United Kingdom
en
Installation and Service Manual
High Efficiency Wall Hung Condensing Gas Boiler
Baxi Combi
224 – 228 – 424 – 428
These instructions include the Benchmark Commissioning Checklist and should be left with the
user for safe keeping.They must be read in conjunction with the Flue Installation Guide.
Dear Customer,
Thank you very much for buying this appliance.
Please read through the manual carefully before using the product, and keep it in a safe place for later reference. In order to
ensure continued safe and efficient operation we recommend that the product is serviced regularly. Our service and customer
service organisation can assist with this.
We hope you enjoy years of problem-free operation with the product.
Contents
Contents
1
Safety . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
1.1 Benchmark . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
1.1.1
Building Regulations and the Benchmark Commissioning Checklist . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .6
1.1.2
The Benchmark Scheme . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
1.1.3
Installer Notification Guidelines . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
1.2 General safety instructions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
1.3 Recommendations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
1.4 Specific safety instructions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
1.4.1
Handling . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .9
1.5 Liabilities . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
1.5.1
Manufacturer's liability . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
1.5.2
Installer's liability . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
1.5.3
User's liability . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
2
About this manual . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
2.1 General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
2.2 Additional documentation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
2.3 Symbols used . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
2.3.1
Symbols used in the manual . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
2.4 Abbreviations/Glossary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
3
Technical specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
3.1 Homologations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
3.1.1
Directives . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
3.1.2
Certifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
3.1.3
Gas category . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
3.1.4
Standards . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
3.2 Technical data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .13
3.2.1
Technical information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .13
3.2.2
Technical parameters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
3.3 Dimensions and connections/clearances . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
3.4 Electrical diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
4
Description of the product . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22
4.1 General description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22
4.2 Operating principle . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22
4.2.1
Air-gas adjustment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .22
4.2.2
Combustion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22
4.2.3
Heating and domestic hot water production . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22
4.3 Main components . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23
4.4 Control panel description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23
4.4.1
Description of the keys . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23
4.4.2
Description of the display . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .23
4.5 Standard delivery . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24
4.5.1
Contents of the carton . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24
4.6 Accessories and options . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24
4.6.1
Optional accessories . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24
5
Before installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25
5.1 Installation regulations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25
5.2 Installation requirements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25
5.2.1
Gas supply . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .25
5.2.2
Electrical supply . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .25
5.2.3
Hard water area . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25
5.2.4
Bypass . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25
5.2.5
System control . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26
5.2.6
Treatment of water circulating systems . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26
5.2.7
Showers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .26
5.2.8
Expansion vessel (CH only) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .26
5.2.9
Pump available head . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27
5.2.10 Safety pressure relief valve . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27
5.3 Choice of the location . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27
5.3.1
Location of the boiler . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27
5.3.2
Data plate and service label . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28
7672024 - 1 - 03112016
3
Contents
5.4
5.5
5.6
5.3.3
Bath and shower rooms . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .29
5.3.4
Ventilation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29
5.3.5
Condensate drain . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30
5.3.6
Clearances . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .32
5.3.7
Flue/chimney location . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32
5.3.8
Horizontal flue/chimney systems . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34
5.3.9
Flue/chimney trim . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35
5.3.10 Terminal guard . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .35
5.3.11 Flue/chimney deflector . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .35
5.3.12 Flue/chimney accessories . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35
Transport . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .35
Unpacking & initial preparation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36
5.5.1
Unpacking . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36
5.5.2
Initial preparation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37
Connecting diagrams . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38
5.6.1
Filling information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .38
5.6.2
Domestic hot water circuit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39
6
Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40
6.1 General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40
6.2 Assembly . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .40
6.2.1
Fitting the pressure relief discharge pipe . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .40
6.2.2
Connecting the condensate drain . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41
6.3 Air supply/flue gas connections . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41
6.3.1
Connecting the flue/chimney . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41
6.4 Electrical connections . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42
6.4.1
Panel removal to make electrical connection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42
6.4.2
Electrical connections of the boiler . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43
6.4.3
Connecting a room thermostat . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43
6.5 Filling the installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .44
6.5.1
Flushing the system . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .44
6.5.2
Fill the installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44
7
Commissioning . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45
7.1 General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45
7.2 Checklist before commissioning . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45
7.2.1
Preliminary electrical checks . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45
7.2.2
Checks . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .45
7.3 Commissioning procedure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46
7.3.1
De-Aeration function . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46
7.4 Gas settings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46
7.4.1
Check the operational (working gas inlet pressure and gas rate) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46
7.4.2
Checking combustion - chimney sweep mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 47
7.5 Configuring the system . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50
7.5.1
System draining . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50
7.6 Final instructions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50
7.6.1
Handover . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50
8
Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .51
8.1 Use of the control panel . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 51
8.1.1
Control . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 51
8.2 Start up . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 51
8.3 Shutdown . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 51
8.4 Frost protection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 51
9
Settings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 52
9.1 Functions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .52
9.2 Information menu . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 52
10 Maintenance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 53
10.1 General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 53
10.2 Standard inspection and maintenance operations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 54
10.2.1 Periodic check and maintenance procedure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 54
10.2.2 Checking the water pressure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 54
10.2.3 Checking the expansion vessel . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 54
10.2.4 Checking the automatic air vent . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 54
4
7672024 - 1 - 03112016
Contents
10.2.5 Checking the burner and cleaning the heat exchanger . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 54
10.3 Specific maintenance instructions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .55
10.3.1 Detection/spark ignition electrode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 55
10.3.2 NTC flue sensor . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .56
10.3.3 Flow and return sensors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 56
10.3.4 Safety overheat thermostat . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 56
10.3.5 HMI control . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 56
10.3.6 Burner/combustion chamber door assembly . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 57
10.3.7 Air/gas unit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .57
10.3.8 Insulation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 59
10.3.9 Heat exchanger . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 59
10.4 Hydraulics maintenance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 60
10.4.1 Expansion vessel . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .60
10.4.2 Pump - complete . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 60
10.4.3 Auto air vent . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .61
10.4.4 Plate heat exchanger . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .61
10.4.5 Hydraulic pressure sensor . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 62
10.4.6 DHW flow sensor (hall effect sensor) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 62
10.4.7 DHW flow regulator and filter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .62
10.4.8 Diverter valve motor . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .63
10.4.9 Diverter valve cartridge . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 63
10.4.10 Pressure relief valve . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 63
11 Troubleshooting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .64
11.1 Error codes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 64
11.2 Fault finding — temporary faults . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 64
11.3 Fault finding - permanent faults . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 65
11.4 Accessing the information menu . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 69
11.5 Reading out operating parameters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 69
11.6 Statuses and sub-statuses . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 70
12 Decommissioning . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 72
12.1 Decommissioning procedure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .72
13 Spare parts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 73
13.1 Short parts list . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 73
14 Appendix . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 74
14.1 Combustion check on small heating systems . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 74
14.2 Benchmark commissioning checklist . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 75
14.3 Service records . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 76
7672024 - 1 - 03112016
5
1 Safety
1
1.1
Safety
Benchmark
1.1.1
Building Regulations and the Benchmark Commissioning
Checklist
Building Regulations (England & Wales) require notification of the installa­
tion of a heating appliance to the relevant Local Authority Building Control
Department. This can be achieved via a Competent Persons Self Certifica­
tion Scheme as an option to notifying the Local Authority directly.
The Health & Safety Executive operates the ’Gas Safe Register’, a selfcer­
tification scheme for gas heating appliances.
This company is a member of the Benchmark initiative and fully supports
the aims of the programme. Its aim is to improve the standards of installa­
tion and commissioning of central heating systems in the UK and to en­
courage the regular servicing of all central heating systems to ensure safe­
ty and efficiency.
Building Regulations require that installations should comply with manu­
facturer’s instructions. It is therefore important that the commissioning
checklist is completed by the installer. The relevant section of Building
Regulations only relates to dwellings. Therefore the checklist only applies
if the appliance is being installed in a dwelling or some related structure.
The flowchart opposite gives guidance for installers on the process neces­
sary to ensure compliance with Building Regulations.
1.1.2
Fig.1
Benchmark
AD-3000725-01
The Benchmark Scheme
Benchmark places responsibilities on both manufacturers and installers.
The purpose is to ensure that customers are provided with the correct
equipment for their needs, that it is installed, commissioned and serviced
in accordance with the manufacturer’s instructions by competent persons
and that it meets the requirements of the appropriate Building Regulations.
The Benchmark Checklist can be used to demonstrate compliance with
Building Regulations and should be provided to the customer for future ref­
erence.
Installers are required to carry out installation, commissioning and servic­
ing work in accordance with the Benchmark Code of Practice which is
available from the Heating and Hotwater Industry Council who manage
and promote the Scheme. Visit www.centralheating.co.uk for more infor­
mation.
6
7672024 - 1 - 03112016
1 Safety
1.1.3
Fig.2
Installer Notification Guidelines
Installer Notification Guidelines
Choose Building
Regulations Notification
Route
Competent Person's
Self Certification Scheme
Building Control
Install and Commission this
appliance to manufacturer's
instructions
Contact your relevant Local
Authority Building Control
(LABC) who will arrange
an inspection or contact
a government approved
inspector
Complete the
Benchmark Checklist
If you notify via the ‘Gas Safe
Register’, the register will issue
the Building Regulations
certificate on members’ behalf
Install and Commission this
appliance to manufacturer's
instructions
Scheme Members only
Call ‘Gas Safe Register’ on:
0800 408 5577
or log onto:
www.gassaferegister.co.uk
within 10 days
Complete the
Benchmark Checklist
You must ensure that the
certificate number issued by
the ‘Gas Safe Register’ is written
onto the Benchmark Checklist
‘Gas Safe Register’ will issue a
Building Regulations Compliance
Certificate to the property owner
and inform the relevant LABC
LABC will record the data
and will issue a
certificate of compliance
AD-3000696-01
7672024 - 1 - 03112016
7
1 Safety
1.2
General safety instructions
Danger
This boiler can be used by children aged 8 years and above and
by persons with reduced physical, sensory or mental capabilities
or lack of experience and knowledge when they have been given
supervision or instruction concerning the safe use of the device
and understand the resulting risks. Children must not be allowed
to play with the appliance. Cleaning and user maintenance must
not be carried out by children without supervision.
Danger
If you smell gas:
1. Do not use a naked flame, do not smoke, do not operate elec­
trical contacts or switches (doorbell, light, motor, lift, etc.).
2. Shut off gas supply.
3. Open the windows.
4. Trace possible leaks and seal them immediately.
5. If the gas leak is before the gas meter, contact the supplier
6. Telephone the National Gas Emergency Service on:- 0800
111 999.
Danger
If you smell flue gases:
1. Switch off the boiler.
2. Open the windows.
3. Trace possible leaks and seal them immediately.
Warning
Do not touch the flue gas pipes. Depending on the boiler settings,
the temperature of the flue gas pipes may exceed 60oC.
Warning
Do not touch the radiators for long periods. Depending on the boil­
er settings, the temperature of the radiators may exceed 60oC.
Warning
Take precautions with the domestic hot water. Depending on the
boiler settings, the domestic hot water temperature may exceed
65oC.
Danger
Before any work, switch off the mains supply to the boiler.
Caution
After maintenance or repair work, check the entire heating installa­
tion to ensure that there are no leaks.
1.3
Recommendations
Warning
Installation and maintenance of the boiler must be carried out by a
qualified installer in accordance with local and national regula­
tions.
Warning
If the mains lead is damaged, it must be replaced by the original
manufacturer, the manufacturer's dealer or another suitably skilled
person to prevent hazardous situations from arising.
Warning
Always disconnect the mains supply and close the main gas tap
when working on the boiler.
8
7672024 - 1 - 03112016
1 Safety
Caution
Make sure the boiler can be reached at all times.
The boiler must be installed in a frost-free area.
In the case of a fixed connection to the power cord, you must al­
ways install a main double pole switch with an opening gap of at
least 3 mm (EN 60335-1).
Drain the boiler and central heating system if you are not going
to use your home for a long time and there is a chance of frost.
The frost protection does not work if the boiler is out of opera­
tion.
The boiler protection only protects the boiler, not the system.
Check the water pressure in the system regularly. If the water
pressure is lower than 0.8 bar, the system must be topped up
(recommended water pressure between 1 and 2 bar).
Important
Keep this document near to the boiler.
Important
Casing panels may only be removed for maintenance and servic­
ing purposes. Refit all panels when maintenance work and servic­
ing are complete.
Note
Instruction and warning labels must never be removed or covered
and must be clearly legible throughout the entire service life of the
boiler. Replace damaged or illegible instruction and warning labels
immediately.
Note
The boiler must not be modified in any way.
1.4
Specific safety instructions
1.4.1
Handling
General
The following advice should be adhered to, from when first handling the
boiler to the final stages of installation, and also during maintenance.
Most injuries as a result of inappropriate handling and lifting are to the
back, but all other parts of the body are vulnerable, particularly should­
ers, arms and hands. Health & Safety is the responsibility of EVERY­
ONE.
There is no "safe" limit for one man - each person has different capabili­
ties. The boiler should be handled and lifted by TWO PEOPLE.
Do not handle or lift unless you feel physically able.
Wear appropriate Personal Protection Equipment e.g. protective gloves,
safety footwear etc.
Preparation
Co-ordinate movements - know where, and when, you are both going.
Minimise the number of times needed to move the boiler - plan ahead.
Always ensure when handling or lifting the route is clear and unobstruc­
ted. If possible avoid steps, wet or slippery surfaces, unlit areas etc. and
take special care on ladders/into lofts.
Technique
When handling or lifting always use safe techniques - keep your back
straight, bend your knees. Don’t twist - move your feet, avoid bending
forwards and sideways and keep the load as close to your body as pos­
sible.
Where possible transport the boiler using a sack truck or other suitable
trolley.
7672024 - 1 - 03112016
9
1 Safety
Always grip the boiler firmly, and before lifting feel where the weight is
concentrated to establish the centre of gravity, repositioning yourself as
necessary. See the "Installation" section of these instructions for recom­
mended lift points.
Remember
The circumstances of each installation are different. Always assess the
risks associated with handling and lifting according to the individual con­
ditions.
If at any time when installing the boiler you feel that you may have in­
jured yourself STOP !! DO NOT "work through" the pain - you may
cause further injury.
IF IN ANY DOUBT DO NO HANDLE OR LIFT THE BOILER — OBTAIN
ADVICE OR ASSISTANCE BEFORE PROCEEDING !
1.5
Liabilities
1.5.1
Manufacturer's liability
Our products are manufactured in compliance with the requirements of the
various Directives applicable. They are therefore delivered with the
marking and any documents necessary. In the interests of the quality of
our products, we strive constantly to improve them. We therefore reserve
the right to modify the specifications given in this document.
Our liability as manufacturer may not be invoked in the following cases:
Failure to abide by the instructions on installing the appliance.
Failure to abide by the instructions on using the appliance.
Faulty or insufficient maintenance of the appliance.
1.5.2
Installer's liability
The installer is responsible for the installation and initial commissioning of
the appliance. The installer must abide by the following instructions:
Read and follow the instructions given in the manuals provided with the
appliance.
Install the appliance in compliance with prevailing legislation and stand­
ards.
Carry out initial commissioning and any checks necessary.
Explain the installation to the user.
If maintenance is necessary, warn the user of the obligation to check the
appliance and keep it in good working order.
Give all the instruction manuals to the user.
1.5.3
User's liability
To guarantee optimum operation of the system, you must abide by the fol­
lowing instructions:
Read and follow the instructions given in the manuals provided with the
appliance.
Call on a qualified professional to carry out installation and initial com­
missioning.
Get your installer to explain your installation to you.
Have the required inspections and maintenance carried out by a quali­
fied installer.
Keep the instruction manuals in good condition close to the appliance.
10
7672024 - 1 - 03112016
2 About this manual
2
2.1
About this manual
General
This manual is intended for the installer of a Baxi Combi boiler.
2.2
Additional documentation
These Installation & Service Instructions must be read in conjunction with
the Flue Accessories Fitting Guide supplied in the Literature Pack.
Various timers, external controls, etc. are available as optional extras. Full
details are contained in the relevant sales literature.
2.3
Symbols used
2.3.1
Symbols used in the manual
This manual uses various danger levels to draw attention to special in­
structions. We do this to improve user safety, to prevent problems and to
guarantee correct operation of the appliance.
Danger
Risk of dangerous situations that may result in serious personal
injury.
Danger of electric shock
Risk of electric shock.
Warning
Risk of dangerous situations that may result in minor personal in­
jury.
Caution
Risk of material damage.
Important
Please note: important information.
See
Reference to other manuals or pages in this manual.
2.4
Abbreviations/Glossary
BS
CH
DHW
GB
HHIC
Hi
Hs
IE
PCU
Pn
Pnc
PWM
Qn
SU
7672024 - 1 - 03112016
British Standard
Central heating
Domestic hot water
Great Britain
Heating and Hotwater Industry Council
Lower heating value (LHV)
Higher heating value (HHV)
Ireland
PCB for managing burner operation
Nominal output
Condensing output
Pulse wide modulation
Nominal input
Safety PCB
11
3 Technical specifications
3
Technical specifications
3.1
Homologations
3.1.1
Directives
Our company declares that these products are provided with the CE mark­
ing in compliance with the essential requirements of the following direc­
tives:
Gas Directive 2009/142/EC;
Electromagnetic Compatibility Directive 2014/30/EU General standards:
EN 61000-6-3, EN 61000-6-1 Standard in reference to: EN 55014;
Electromagnetic Compatibility Directive 2014/30/EU General standards:
EN 61000-6-3, EN 61000-6-1 Standard in reference to: EN 55014.
For appliances connected to the electricity network: Comply with the
prevailing provisions for low-voltage electrical equipment;
Low Voltage Directive 2014/35/EU General standard: EN 60335–1
Standard in reference to: EN 60335–2-102;
Efficiency Directive 92/42/EC
Ecodesign Directive 2009/125/EC;
Directive on energy consumption 2010/30/EC; Regulation (EU) No.
813/2013 and 814/2013.
Energy Labelling Directive 2010/30/EU: Regulation 811/2013 and
812/2013
In addition to the provisions and legal directives, also the complementary
directives described in these instructions must be observed. All the sup­
plements and additional requirements are applicable at the moment of in­
stallation.
3.1.2
Tab.1
Certifications
Certifications
CE certificate number
0085CQ0192
NOx class
5 (EN 15502)
Boiler type
C13, C33
3.1.3
Tab.2
Gas category
Gas category, type and supply pressure
Gas category
Gas type
Supply pressure (mbar)
I2H
G20
20
3.1.4
Standards
Codes of Practice — refer to the most recent version
Tab.3
12
In GB the following Codes of Practice apply:
Standard
Scope
BS 6891
Gas Installation.
BS 5546
Installation of hot water supplies for domestic purposes.
BS EN
12828
Heating systems in buildings.
7672024 - 1 - 03112016
3 Technical specifications
Standard
Scope
BS EN
12831
Heating systems in buildings — Calculation of load.
BS EN
14336
Installation & commissioning of water based heating sys­
tems.
BS 6798
Installation of gas fired hot water boilers.
BS 5440
Part 1
Flues.
BS 5440
Part 2
Ventilation.
BS 7074
Expansion vessels and ancillary equipment for sealed wa­
ter systems.
BS 7593
Treatment of water in domestic hot water central heating
systems.
BS 4814
Specification for Expansion Vessels using an internal dia­
phragm, for sealed hot water systems.
IGE/UP/
7/1998
Guide for gas installations in timber framed housing.
Tab.4
In IE the following Code of Practice apply:
Standard
Scope
IS 813
Domestic Gas Installations.
The following standards give valuable additional information:
3.2
BS 5546
Installation of hot water supplies for domestic purposes.
BS EN
12828
Heating systems in buildings.
BS EN
12831
Heating systems in buildings — Calculation of load.
BS EN
14336
Installation & commissioning of water based heating sys­
tems.
BS 7074
Expansion vessels and ancillary equipment for sealed wa­
ter systems.
BS 7593
Treatment of water in domestic hot water central heating
systems.
Technical data
3.2.1
Technical information
Important
All data in these sections are nominal and subject to normal pro­
duction tolerances.
Tab.5
General
Baxi Combi
224
228
424
428
Gas Council Numbers
47–077–21
47–077–22
47–077–23
47–077–24
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13
3 Technical specifications
Baxi Combi
224
228
424
428
Nominal heat input Domes­ Nett (Qn
tic Hot Water — Maximum Hi)
Rate
Gross
(Qn Hs)
kW
24.7
28.9
24.7
28.9
kW
27.4
32.1
27.4
32.1
Nominal Heat Input Central Nett (Qn
Heating — Maximum Rate Hi)
kW
20.6
24.7
20.6
24.7
Gross
(Qn Hs)
kW
22.9
27.4
22.9
27.4
Nominal Heat Input — Min­ Nett (Qn
imum Rate
Hi)
kW
4.9
4.9
4.9
4.9
Gross
(Qn Hs)
kW
5.4
5.4
5.4
5.4
Pn
kW
24.0
28.0
24.0
28.0
Nominal heat output
Pn
80/60°C — Central Heating
— Maximum Rate
kW
20.0
24.0
20.0
24.0
Nominal heat output
Pn
80/60°C — Central Heating
— Factory Setting
kW
20.0
20.0
20.0
20.0
Nominal heat output
80/60°C — Minimum Rate
kW
4.8
4.8
4.8
4.8
Nominal heat output
Pnc
50/30°C — Central Heating
— Maximum Rate
kW
21.8
26.1
21.8
26.1
Nominal heat output
Pnc
50/30°C — Central Heating
— Minimum Rate
kW
5.2
5.2
5.2
5.2
Nominal heat output
80/60°C — Domestic Hot
Water — Maximum Rate
Tab.6
Pn
Central heating circuit specifications
Baxi Combi
224
228
424
428
Maximum pressure
bar
3
3
3
3
Minimum pressure
bar
0.5
0.5
0.5
0.5
Central heating temperature adjust­
ment ±5°C
°C
25/80
25/80
25/80
25/80
litres
7.0
7.0
7.0
7.0
Expansion vessel pre charge pres­
sure
bar
1.0
1.0
1.0
1.0
Maximum capacity of central heat­
ing system
litres
120
120
120
120
Primary water content of boiler (un­
pressurised)
litres
2.5
2.5
2.5
2.5
224
228
424
428
Expansion vessel water capacity
Tab.7
Domestic hot water circuit specifications
Baxi Combi
Maximum pressure
bar
8.0
8.0
8.0
8.0
Dynamic minimum pressure
bar
0.5
0.5
0.5
0.5
l/min
2.0
2.0
2.0
2.0
Minimum working water flow rate
14
7672024 - 1 - 03112016
3 Technical specifications
Baxi Combi
224
228
424
428
l/min
11.5
13.4
11.5
13.4
°C
35/60
35/60
35/60
35/60
Production of domestic water with
ΔT = 30°C
l/min
11.4
13.3
11.4
13.3
Production of domestic water with
ΔT = 35°C
l/min
9.8
11.5
9.8
11.5
Specific flow rate (D)
Domestic hot water temperature
range adjustment ±5°C
Where low flow taps or fittings are intended to be used in the DHW system connected to the boiler, it is strongly recommended
that the DHW flow rate DOES NOT fall below 2.5 l/min. This will ensure reliable operation of the DHW function.
Tab.8
Characteristics of combustion
Baxi Combi
224
228
424
428
Natural gas rate (G20) Qmax
m3/h
2.61
3.06
2.61
3.06
Natural gas rate (G20) Qmin
m3/h
0.52
0.52
0.52
0.52
Diameter of coaxial discharge
pipes
mm
60/100 & 80/125
60/100 & 80/125
60/100 & 80/125
60/100 & 80/125
Important
Dynamic (nominal) inlet pressure (Natural gas — G20) 20mbar
with a CV of 37.78 MJ/m3
Tab.9
Electrical specifications
Baxi Combi
224
228
424
428
Nominal electrical power supply
voltage
V
230
230
230
230
Nominal electrical power supply
frequency
Hz
50
50
50
50
Nominal power consumption when
firing
W
84
94
84
94
External fuse rating
Amp
3
3
3
3
F2 Internal fuse rating — Connec­
tion board ’B’
Amp
0.5
0.5
0.5
0.5
F1 Internal fuse rating — Main PCB
board ‘A’
Amp
1.6
1.6
1.6
1.6
Important
Boiler must be connected to an earth supply.
Tab.10
Other specifications
Baxi Combi
224
228
424
428
Degree of protection against hu­
midity (EN 60529) without plug-in
timer / receiver fitted
IP
IPX5D
IPX5D
IPX5D
IPX5D
Degree of protection against hu­
midity (EN 60529) with plug-in tim­
er / receiver fitted
IP
IPXO
IPXO
IPXO
IPXO
700/395/279
700/395/279
700/395/279
700/395/279
Dimensions (height/width/depth)
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mm
15
3 Technical specifications
Tab.11
Connections (copper tails)
Baxi Combi
224
228
424
428
Gas inlet
mm
22
22
22
22
Heating flow
mm
22
22
22
22
Heating return
mm
22
22
22
22
Cold water inlet
mm
15
15
15
15
Hot water outlet
mm
15
15
15
15
Pressure relief discharge
mm
15
15
15
15
Condensate discharge drain plastic
waste pipe
mm
21.5
21.5
21.5
21.5
224
228
424
428
Tab.12
Clearances
Baxi Combi
Above casing
mm
183
183
183
183
Below casing (min)
Below casing (recommended)
mm
mm
200
250
200
250
200
250
200
250
Front — for servicing (min)
Front — for servicing (recommen­
ded)
mm
mm
450
1000
450
1000
450
1000
450
1000
Front — for operation
mm
6
6
6
6
Sides LH
mm
5
5
5
5
Sides RH
mm
5
5
5
5
224
228
424
428
Tab.13
Weights
Baxi Combi
Packaged boiler
kg
30.0
30.0
30.5
30.5
Boiler lift weight (dry)
kg
26.0
26.0
26.0
26.0
Installed weight (dry)
kg
28.0
28.0
28.5
28.5
Installed weight when filled with wa­
ter
kg
30.5
30.5
31.0
31.0
3.2.2
Tab.14
Technical parameters
Technical parameters for boiler combination heaters
Baxi Combi
224
228
424
428
Yes
Yes
Yes
Yes
No
No
No
No
B1 boiler
No
No
No
No
Cogeneration space heater
No
No
No
No
Combination heater
Yes
Yes
Yes
Yes
Condensing boiler
Low-temperature boiler
(1)
Rated heat output
Useful heat output at rated heat output
and high temperature regime(2)
16
Prated
kW
20
24
20
24
P4
kW
20.0
24.0
20.0
24.0
7672024 - 1 - 03112016
3 Technical specifications
Baxi Combi
224
228
424
428
Useful heat output at 30% of rated heat
output and low temperature regime
P1
kW
6.7
8.0
6.7
8.0
Seasonal space heating energy efficiency
ƞs
%
93
93
93
93
Useful efficiency at rated heat output and ƞ4
high temperature regime
%
88.1
88.0
88.1
88.0
ƞ1
%
97.8
97.8
97.8
97.8
Full load
elmax
kW
0.028
0.038
0.028
0.038
Part load
elmin
kW
0.011
0.011
0.011
0.011
Standby mode
PSB
kW
0.003
0.003
0.003
0.003
Standby heat loss
Pstby
kW
0.069
0.069
0.069
0.069
Ignition burner power consumption
Pign
kW
0.000
0.000
0.000
0.000
Annual energy consumption
QHE
GJ
62
74
62
74
Sound power level, indoors
LWA
dB
48
50
48
50
Emissions of nitrogen oxides
NOX
mg/kWh
38
40
38
40
XL
XL
XL
XL
Useful efficiency at 30% of rated heat
output and low temperature regime
Auxiliary electricity consumption
Other items
Domestic hot water parameters
Declared load profile
Daily electricity consumption
Qelec
kWh
0.151
0.151
0.151
0.151
Annual electricity consumption
AEC
kWh
33
33
33
33
Water heating energy efficiency
ƞwh
%
86
85
86
85
Daily fuel consumption
Qfuel
kWh
22.770
22.930
22.770
22.939
Annual fuel consumption
AFC
GJ
17
17
17
17
(1) Low temperature means for condensing boilers 30°C, for low temperature boilers 37°C and for other heaters 50°C return temperature
(at heater inlet).
(2) High temperature regime means 60°C return temperature at heater inlet and 80°C feed temperature at heater outlet.
See
The back cover for contact details.
7672024 - 1 - 03112016
17
3 Technical specifications
3.3
Fig.3
Dimensions and connections/clearances
Dimensions and connections
700
1
2
8
3
395
4
2 79
5
6
7
PN-0000264
Fig.4
Clearances
5.0
5.0
183
395
700
Safety valve
Heating circuit water flow
Condensate discharge
Heating system/boiler drain tap
Domestic hot water outlet
Gas inlet
Mains cold water inlet
Heating circuit water return
A*
B*
Clearances below — 200mm minimum, 250mm recommended
Clearances in front — 450mm minimum, 1000mm recommended
The clearances shown in the diagram are minimum requirements to allow
for case removal, spanner access and air movement. These should be ob­
served at all times and kept clear of obstructions.
6
285
1
2
3
4
5
6
7
8
A*
B*
PN-0000205
18
7672024 - 1 - 03112016
3 Technical specifications
Fig.5
Paper template
Clearance above 183
116 Dia Minimum
Aperture For
Flue Tube
50 MIN
Vertical Flue
Centre Line
Ø8
198
198
Side Clearance 5
Side Clearance 5
View from under boiler
Wall
34
82.5
33.5
65
Heating
Flow
(22mm)
65
65
Hot Water
Outlet
(15mm)
Cold Water
Inlet
(15mm)
Combi Only
Not System
Combi Only
Not System
67.5
Heating
Return
(22mm)
32
Ø 22
65
Clearance below 250
PN-0000223
7672024 - 1 - 03112016
19
3 Technical specifications
3.4
Fig.6
Electrical diagram
Electrical diagram
F1 (1,6A)
E
G/Y
W
GND
Gy
Bl
W
Bk
R
Br
Vt
Gn
W
R
Bk
HMI
R
Br
Bk
Wk
Gn
L-BUS
X9-1
13
F1
G/Y
1
X6-A
JP1
Br
L
Bl
N
230V - 50Hz
X1-A
1
X14-A
A
W4
W1
SIG
1
W5
C1
W2
C2
+
ST
F
1
R
W3
1
R
R
Br
Br
Vt
16
Vt
Vt
R
Br
1
X4-A
W8-1
1
L(DW)
N
Bl Br Bk
W8-4
W8-2
L
N
L(CH)
X3-A
W8
1
P
W8-3
R Bk Bk
Bl
Br
Br
Bl
X5-A
R
Vt
R
Bk
Bk
Br
Gn
W
R
G/Y
X2-A
FS DS RS
Br
R
Bl Gn Y
GV
DV
Br Gn W
PWM - P
HS
WPS
L-BUS
TIMER
Bl
W Br
Gn Bk R
Bk Br
R
Gy
Bl
Gy
1
12 34 5
1 2 34 567
12
X12
X11
X10
Br
1
1 2 3
X3
X5
X2
B
J
X9
X13
2
X8
OT
X14 X7
OS
G/Y
Br
Bk
Bl
W Vt
X1 MAINS
X6
X4
RT
L-BUS
F2
0.5A
N L
230V - 50Hz
On
SERVICE
Off
321
PN-0000268
1
2
Circuit board ‘A’
Circuit board ‘B’
Tab.15
Circuit board wiring
Br
Brown
Gy
Grey
Gn
Green
Bl
Blue
R
Red
W
White
Vt
Violet
G/Y Green/Yellow
Bk
20
Mains (230V)
Black
7672024 - 1 - 03112016
3 Technical specifications
Tab.16
Electrical connections inside the boiler (A)
Electrical power supply 230 V — 50 Hz
X1–A
1: Earthing connector
2: L (230 V)
3: N
Pump
X2–A
1: Earth connection
2: L (230 V)
3: N
3-way valve
X3–A
X4–A
1: L (CH) 230 V — Heating circuit opening command
2: L (DW) 230 V — Domestic water circuit opening command
3: N — Common
Pump PWM signal
Sensor connection
X5–A
HS: domestic water request
RS: heating circuit water return
DS: heating circuit water flow
FS: flue gas
WPS: hydraulic pressure switch
ST: safety thermostat
X6–A
Boiler PCB and control panel connection (electrical connection board)
X13–A
Not used
X14–A
Connection L-BUS
Tab.17
Electrical connections to be made to the boiler (B)
Electrical power supply 230 V — 50 Hz
X1–B
1: N
2: L (230 V)
3: Earthing connector
X4–B
Room thermostat/timer (230V)
X6–B
Not used
X7–B
Solar probe connection
X8–B
On-Off/R-Bus - Room thermostat connection (the jumper must be REMOVED to connect a device)
X9–B
Service connection (SERVICE)
X13–B
Connection L-BUS
X14–B
Outside sensor connection (OS)
Dip-Switch
J
1: Maximum heating temperature OFF = 80°C - ON = 45°C (floor system)
2: OFF = Maximum output (heating) - ON = Boiler output 50% (heating)
3: DO NOT ADJUST
7672024 - 1 - 03112016
21
4 Description of the product
4
4.1
Description of the product
General description
The Baxi Combi condensing boiler is a gas-fuelled boiler. The purpose of
this boiler is to heat water to a temperature that is lower than boiling point
at atmospheric pressure. It must be connected to a heating installation and
to a domestic hot water distribution system that is compatible with its pow­
er and performance ratings. Features of this boiler:
Low pollutant emissions.
High-efficiency heating.
Combustion products discharged through a coaxial connector.
Front control panel with display.
Lightweight and compact.
4.2
Operating principle
4.2.1
Air-gas adjustment
The air is drawn in by the fan and gas injected directly at the top of the
mixer valve. The fan rotation speed is regulated automatically by the elec­
tronic board based on temperature adjustment and other parameters. The
gas and air are mixed in the manifold. The gas/air ratio ensures that the
quantity of gas and air are adjusted correctly to always obtain optimal
combustion. The gas/air mixture is fed into the burner at the front of the
heat exchanger. The mixture is ignited by the spark electrode.
4.2.2
Combustion
The burner heats the heating water circulating in the heat exchanger.
When the temperature of the combustion gas is lower than the dew point
(around 55 °C), the water vapour contained in the combustion gas con­
denses in the flue gas side of the heat exchanger. The heat recovered
during this condensation process (the latent heat or condensing heat) is
also transferred to the heating water. Once cooled, the combustion gases
are discharged through the flue exhaust. The condensed water is dis­
charged through a trap.
4.2.3
Heating and domestic hot water production
In boilers used for heating and for producing domestic hot water, an inte­
grated plate heat exchanger heats the domestic water. The heated water
is then channelled to the heating installation or to the plate heat exchanger
via a three-way valve. A flow sensor detects that a hot water tap has been
turned on and communicates this to the PCB, which switches the threeway valve to the hot water position and activates the pump. The three-way
valve is spring-loaded but only consumes electricity when switching from
one position to another. Priority is given to domestic hot water.
22
7672024 - 1 - 03112016
4 Description of the product
4.3
Main components
Component description
Fig.7
1
3
2
4
28
5
6
27
7
8
26
9
25
24
23
10
22
11
12
21
13
20 19
18 17 16 15
14
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
Boiler case
Mounting slots for wall bracket
Flue adaptor
Expansion vessel air control/filling valve
Expansion vessel
Burner door
Detection/ignition electrode
Water circuit-expansion vessel connection pipe
Air-gas assembly (control board, fan, mixer valve)
Automatic air vent
Gas valve
Pump
3-way valve
Pressure gauge (fitted on the panel)
Domestic hot water priority sensor
Boiler electrical connection board
Domestic hot water plate heat exchanger fastening screws
Domestic hot water plate heat exchanger
Pressure relief valve
Condensate trap
Hydraulic pressure sensor
Silencer
Trap quick connection (with gaskets)
Heating circuit water flow sensor
Overheat safety thermostat
Heating circuit water return sensor (behind the silencer)
Heat exchanger
Flue gas temperature sensor
PN-0000286
4.4
Control panel description
4.4.1
Fig.8
Control panel
Description of the keys
Heating temperature control knob
Level access button: Information, Installer or Chimney Sweep
Manual reset button
Domestic hot water temperature control knob
PN-0000266
4.4.2
Fig.9
Display screen
Description of the display
Hour run meter
Malfunction
Maintenance
Reset necessary
Burner status
Heating mode
PN-0000267
7672024 - 1 - 03112016
Outside temperature sensor
Domestic hot water mode
23
4 Description of the product
4.5
Standard delivery
4.5.1
Contents of the carton
The boiler is delivered in a carton comprising:
a wall-hung gas boiler;
a bracket for fastening the boiler to the wall;
a paper template;
an installation and service manual;
a user manual.
a fitting kit, including taps and tail pipes.
4.6
Accessories and options
4.6.1
Optional accessories
The table below shows the accessories available for this boiler range.
Tab.18
Optional accessories
Part number
Accessory
7658276
Baxi plug-in 24 hr mechanical timer combi - RH
7658523
Baxi plug-in 7 day digital timer combi - RH
7658781
Baxi plug-in receiver 24 hr RF programmable mech room
thermostat-combi
7658789
Baxi plug-in receiver 7 day RF digital programmable room
thermostat-combi
7212438
Baxi single channel wired programmable room thermostat
7212444
Baxi single channel wired timer
720971601
Baxi room thermostat
720330001
Baxi wired weather sensor
720648301
Multifit condensate & PRV combined pump
720644401
Multifit 1m condensate drain pipe 'trace heating' element
720664101
Multifit 2m Condensate drain pipe 'trace heating' element
720664201
Multifit 3m condensate drain pipe 'trace Heating' element
720664401
Multifit 5m condensate drain pipe 'trace heating' element
7659335
Baxi 200-400 stand off kit
5121379
Multifit remote secondary PRV kit
248221
Multifit filling loop (Not required for 424 and 428)
For Flue Accessories (elbows, extensions, clamps etc.) refer to the Flue
Installation Guide supplied in the literature pack.
Any of the above MUST be fitted ONLY by a qualified competent person.
Further details can be found in the relevant sales literature and at
www.baxi.co.uk
24
7672024 - 1 - 03112016
5 Before installation
5
5.1
Before installation
Installation regulations
Warning
Installation, repair and maintenance must only be carried out by a
competent person. This document is intended for use by compe­
tent persons.
Installation must be carried out in accordance with the prevailing regula­
tions, the code of practice and the recommendations in these instructions.
Installation must also respect the following points:
This instruction manual and any other applicable documentation.
Building Regulations.
British Standards.
Gas Safety Regulations.
Water Supply Regulations,
5.2
Installation requirements
5.2.1
Gas supply
The gas installation should be in accordance with the relevant standards.
In GB this is BS 6891 (NG). In IE this is the current edition of IS 813 Do­
mestic Gas Installations.
The connection to the appliance is a 22mm copper tail located at the rear
of the gas service cock.
Ensure that the pipework from the meter to the appliance is of adequate
size, and the demands of any other gas appliances in the property are tak­
en into consideration. Do not use pipes of a smaller diameter than the boil­
er gas connection (22mm) UNLESS the stated gas rate can be achieved
with pipe of lesser diameter and with all other gas appliances operating at
maximum rate.
5.2.2
Electrical supply
External wiring must be correctly earthed, polarised and in accordance
with relevant regulations/rules. In GB this is the current IEE Wiring Regula­
tions. In IE reference should be made to the current edition of ETCI rules.
The mains supply is 230V ~ 50Hz fused at 3A.
Important
The method of connection to the electricity supply must facilitate
complete electrical isolation of the appliance.
Connection may be via a fused double-pole isolator with a contact
separation of at least 3mm in all poles and servicing the boiler and
system controls only.
5.2.3
Hard water area
Important
Only water that has NOT been artificially softened must be used
when filling or re-pressurising the primary system. If the mains
cold water to the property is fitted with an artificial softening/treat­
ment device the source utilised to fill or re-pressurise the system
must be upstream of such a device.
5.2.4
Bypass
The boiler is fitted with an automatic integral bypass.
7672024 - 1 - 03112016
25
5 Before installation
5.2.5
System control
Further external controls (e.g. room thermostat sensors) MUST be fitted to
optimise the economical operation of the boiler in accordance with Part L
of the Building Regulations. A range of optional controls is available. Full
details are contained in the relevant Sales Literature.
5.2.6
Treatment of water circulating systems
All recirculatory water systems will be subject to corrosion unless an ap­
propriate water treatment is applied. This means that the efficiency of the
system will deteriorate as corrosion sludge accumulates within the system,
risking damage to pump and valves, boiler noise and circulation problems.
When fitting new systems flux will be evident within the system, which can
lead to damage of system components.
BS 7593 gives extensive recommendations on system cleansing and wa­
ter treatment.
All systems must be thoroughly drained and flushed out using appropriate
proprietary flushing agent.
A suitable inhibitor must then be added to the system.
All system additives (flushing agents, cleansers, inhibitors etc.) must com­
ply with the requirements of BS 7593. Full instructions are supplied with
the products and for further information contact the additive manufacturer
directly or consult their website.
Important
Failure to flush and add inhibitor to the system will invalidate the
appliance warranty.
It is important to check the inhibitor concentration after installation, system
modification and at every service in accordance with the inhibitor manufac­
turer. (Test kits are available from inhibitor stockists.)
For information or advice regarding any of the above contact Baxi Custom­
er Support 0344 871 1545.
5.2.7
Showers
If a shower control is supplied from the appliance it should be of the ther­
mostatic or pressure balanced type. Thermostatic type shower valves pro­
vide the best comfort and guard against water at too high a temperature.
Existing controls may not be suitable - refer to the shower valve manufac­
turer.
5.2.8
Expansion vessel (CH only)
The appliance expansion vessel is pre-charged to 1.0 bar. Therefore, the
minimum cold fill pressure is 1.0 bar. The vessel is suitable for correct op­
eration for system capacities up to 120 litres. For greater system capaci­
ties an additional expansion vessel must be fitted.
For GB refer to BS 7074 Pt 1. For IE, the current edition of IS 813 Domes­
tic Gas Installations.
Checking the charge pressure of the vessel - to check the charge accu­
rately ensure the system is cold. It is also necessary to relieve the pres­
sure by draining the boiler. Using a suitable gauge check the pressure at
the valve on the underside of the vessel. Adjust the pressure as required
and repressurise the system.
26
7672024 - 1 - 03112016
5 Before installation
5.2.9
Pump available head graph
Fig.10
This is a two-speed (85% CH and 100% DHW) high static head pump fit
for installation on any type of single or double pipe CH system. The auto­
matic air valve incorporated in the pump allows quick venting of the heat­
ing systems.
6.0
5.5
5.0
H (mH20)
Pump available head
4.5
Tab.19
100%
4.0
3.5
85%
Pump head
Q
Flow
85%
Speed in the CH
mode
H
Head
100%
Speed in the
DHW mode
3.0
2.5
2.0
1.5
0
200
400
800
600
1000
Q (l/h)
PN-0000270
5.2.10
Fig.11
Discharge pipe
1
2
A
Discharge pipe
Pressure relief valve
The end of the pipe should terminate facing down and towards the
wall
See
See BS 6798 for full details.
1
The pressure relief valve is set at 3 bar, therefore all pipework, fittings, etc.
should be suitable for pressures in excess of 3 bar and temperature in ex­
cess of 100°C.
2
A
Safety pressure relief valve
The pressure relief discharge pipe should be not less than 15mm diame­
ter, run continuously downward, and discharge outside the building, pref­
erably over a drain. It should be routed in such a manner that no hazard
occurs to occupants or causes damage to wiring or electrical components.
If it is anticipated that any part of the pipe may be subject to freezing it
should be suitably insulated. The end of the pipe should terminate facing
down and towards the wall.
1
PN-0000272
The discharge must not be above a window, entrance or other public ac­
cess. Consideration must be given to the possibility that boiling water/
steam could discharge from the pipe.
Important
The relief valve must never be used to drain the system.
A remote relief valve kit is available to enable the boiler to be installed in
cellars or similar locations below outside ground level.
A boiler discharge pump is available which will dispose of both condensate
& high temperature water from the relief valve. It has a maximum head of
5 metres.
5.3
Choice of the location
5.3.1
Location of the boiler
The boiler may be fitted to any suitable wall with the flue passing through
an outside wall or roof and discharging to atmosphere in a position permit­
ting satisfactory removal of combustion products and providing an ade­
quate air supply. The boiler should be fitted within the building unless oth­
erwise protected by a suitable enclosure i.e. garage or outhouse. (The
boiler may be fitted inside a cupboard.)
Where the boiler is sited in an unheated enclosure and during periods
when the heating system is to be unused it is recommended that the per­
manent live is left on to give BOILER frost protection. NOTE: THIS WILL
NOT PROTECT THE SYSTEM !
7672024 - 1 - 03112016
27
5 Before installation
If the boiler is fitted in a room containing a bath or shower reference must
be made to the relevant requirements.
In GB this is the current IEE Wiring Regulations and Building Regulations.
In IE reference should be made to the current edition of IS 813 Domestic
Gas Installations and the current ETCI rules.
If the boiler is to be fitted into a building of timber frame construction then
reference must be made to the current edition of Institute of Gas Engi­
neers Publication IGE/UP/7 (Gas Installations in Timber Framed Housing).
5.3.2
Fig.12
Data plate position
The data plate is located on the top inner part of the boiler. To see it, re­
move the front panel of the boiler. The data plate provides important infor­
mation about the boiler.
“Code”
“ BRAND ” “Product
name”
kW
Qn Hi
4,9-20,6 4,9-24,7 kW
Pn 80/60°C 4,8-20
kW
kW
4,8-24
Pn 50/30°C 5,2-21,8
kW
kW
3 bar <95 °C
PMS
0085
PMW
8 bar
D
10,9 l/min
230 V~50 Hz - 84 W - IP X5D
NOx
5
Tab.20
C13 C33
I 2H
GB
X
2H - G20 - 20 mbar
3P - G31 - 37 mbar
CN1=1 CN2=1
s/n: 143800001
Data plate and service label
Description of the data plate
"BRAND"
Commercial brand
"Product name"
Model name
"Code"
Product code
Qn Hi
Nominal input
Pn
Effective rated output (delivery 80°
C return 60° C)
PMS
Maximum heating circuit pressure
(bar)
72xxxxx.xx
Maximum domestic water circuit
pressure (bar)
PN-0000273
Fig.13
D
Specific flow rate (l/min)
NOx
NOx class
IP
Protection rating
V-Hz-W
Power supply and output
Cxx/Bxx
Flue gas exhaust type
II2HM3B/P — IT (example)
Gas category used (depends on
the country of destination)
C1/C2
Factory parameters
s/n
Serial number
Service label position
BO-0000011
28
7672024 - 1 - 03112016
5 Before installation
Fig.14
Service label
The service label is at the base of the cover of the terminal block under the
control panel.
Tab.21
“Code”
“Product name”
“s/n”
BO-0000012
"Code"
Product code
"Product name"
Model name
"s/n"
Serial number
5.3.3
Fig.15
Bathroom 1
B
A
B
C
D
E
F
D
Description of the service label
Bath and shower rooms
Zone 0
Zone 1
Zone 2
Window recess Zone 2
Ceiling
Outside zones
C
A
0.6m
D
PN-0000200
Fig.16
Bathroom 2
Important
Where an optional plug-in integral timer, RF receiver or thermostat
is NOT FITTED the boiler has a protection rating of IPX5D and if
installed in a room containing a bath or shower can be within Zone
2 (but not 0 or 1).
E
D
Important
A boiler fitted with an optional plug-in integral timer, RF receiver or
thermostat CANNOT be fitted in any zone.
F
Bathroom 1 and 2 ( in GB only) shows zone dimensions for a bathtub. For
other examples refer to the Current IEE Wiring Regulations). Reference
must be made to the relevant requirements.
2.25m
B
C
In GB this is the current IEE. Wiring Regulations and Building Regulations.
A
In IE reference should be made to the current edition of IS 813 “Domestic
Gas Installations” and the current ETCI rules.
0.6m
PN-0000201
5.3.4
Ventilation
Where the appliance is installed in a cupboard or compartment, no air
vents are required. BS 5440: Part 2 refers to room sealed appliances in­
stalled in compartments. The appliance will run sufficiently cool without
ventilation.
7672024 - 1 - 03112016
29
5 Before installation
5.3.5
Fig.17
Key to pipework
32mm
21.5mm
It is strongly recommended to discharge internally into the household
drainage system. If connecting to a rain water drain, that drain MUST dis­
charge into a foul drain.
2
1
PN-0000202
1
2
3
4
5
6
7
8
9
10
11
12
Fig.18
Tab.22
Methods of termination
5
A
4
A
Termination to an internal soil and vent pipe.
B
External termination via internal discharge branch e.g. sink waste
— downstream (It is NOT RECOMMENDED to connect upstream
of the sink or other waste water receptacle!)
C
Termination to a drain or gully.
D
Termination to a purpose made soakaway Further specific re­
quirements for soakaway design are referred to in BS 6798
E
Pumped into an internal discharge branch (e.g. sink waste) down­
stream of the trap.
F
Pumped into an external soil and vent pipe.
G
Termination to a drain or gully with extended external run and
trace heating. The "Trace Heating" element must be installed in
accordance with the instructions supplied. External runs and
those in unheated locations still require insulation.
3
7
5
Examples are shown of the following methods of termination
Description
5
B
Key to pipework.
Insulation.
50mm per metre of pipe run — 2.5° minimum run.
450mm minimum is applicable to properties up to 3 storeys. For
multi-storey building installations consult BS 6798.
Boiler.
Sink.
Pipe must terminate above water level but below surrounding sur­
face. Cut end at 45°.
Holes in the soak-away must face away from the building.
500mm mimimum.
Basement or similar (heated)
Condensate pump
Unheated Location (e.g. Garage)
Key
3
6
Condensate drain
C
3
7
5
D
9
3
8
PN-0000203
30
7672024 - 1 - 03112016
5 Before installation
Fig.19
Methods of termination continued
6
3
7
10
5
E
11
3
12
The condensate outlet will accept 21.5mm (3/4in) plastic overflow pipe. It is
strongly recommended that this discharges internally into the household
drainage system. Where this is not possible, discharge into an outside
drain is permissible providing every possible precaution is taken to prevent
freezing.
10
5
F
11
5
Ensure the discharge of condensate complies with any national or local
regulations in force. BS 6798 & Part H1 of the Building Regulations give
further detailed guidance.
G
3
Important
Failure to install the condensate discharge pipework correctly will
affect the reliable operation of the boiler.
Careful consideration must be given to the possibility of the pipe­
work being subject to freezing conditions and appropriate meas­
ures taken to prevent blockage. Correct installation in accordance
with this section will considerably minimise the likelihood of block­
age and subsequent boiler lock-out.
A condensate discharge pump and pipe "Trace Heating" are avail­
able as accessories.
The condensate discharge pipe MUST NOT RISE at any point
along its length. There MUST be a fall of AT LEAST 2.5° (50mm
per metre) along the entire run EXCEPT when employing a suita­
ble condensate pump in basement and cellar or similar applica­
tions.
The boiler condensate trap incorporates a seal of 75mm, therefore
it is unnecessary to install an air break and trap in the discharge
pipework.
The discharge pipe should be run in a proprietary drain pipe material e.g.
PVC, PVC-U, ABS, PVC-C or PP.
7
Metal pipework is NOT suitable for use in condensate discharge systems.
PN-0000204
The pipe should be a minimum of 21.5mm diameter and must be suppor­
ted using suitably spaced clips of the correct design to prevent sagging.
It is advisable that the full length of condensate pipe is run internally and
preferably be less than 3 metres.
Internal runs greater than 3 metres or runs in cold areas should use 32mm
waste pipe.
External runs MUST be a MINIMUM of 32mm and fully insulated with ma­
terial suitable for external use.
If the boiler is fitted in an unheated location the entire condensate dis­
charge pipe should be treated as an external run and sized and insulated
accordingly.
In all cases discharge pipe must be installed to aid disposal of the conden­
sate. To reduce the risk of condensate being trapped, as few bends and
fittings as possible should be used and any burrs on cut pipe removed.
When discharging condensate into a soil stack or waste pipe the effects of
existing plumbing must be considered. If soil pipes or waste pipes are sub­
jected to internal pressure fluctuations when WC's are flushed or sinks
emptied then backpressure may force water out of the boiler trap and
cause appliance lockout.
A boiler discharge pump is available which will dispose of both condensate
& high temperature water from the relief valve. It has a maximum head of
5 metres. Follow the instructions supplied with the pump.
Condensate Drain Pipe "Trace Heating" Elements are available in various
lengths, 1, 2, 3 & 5 metres. Where the drain is between 3 & 5 metres a 5
metre kit can be used and "doubled back" upon itself.
It is possible to fit the element externally on the condensate drain or inter­
nally as detailed in the instructions provided.
The fitting of a "Trace Heating" Element is NOT a substitute for correct in­
stallation of the condensate drain. ALL requirements in this section must
still be adhered to.
7672024 - 1 - 03112016
31
5 Before installation
5.3.6
Fig.20
Clearances
Clearances
A flat vertical area is required for the installation of the boiler and it should
be capable of bearing the weight of the boiler when full of water.
These dimensions include the necessary clearances around the boiler for
case removal, spanner access and air movement. Additional clearances
may be required for the passage of pipes around local obstructions such
as joists running parallel to the front face of the boiler.
5.0
5.0
183
A*
B*
395
Clearance below — 200mm minimum, 250mm recommended
Clearance in front — 450mm minimum, 1000mm recommended
700
6
A*
285
B*
PN-0000205
Flue/chimney location
5.3.7
The following guidelines indicate the general requirements for siting bal­
anced flue terminals. For GB recommendations are given in BS 5440 Pt 1.
For IE recommendations are given in the current edition of I.S. 813 Do­
mestic Gas Installations.
Important
Due to the nature of the boiler a plume of water vapour will be dis­
charged from the flue. This should be taken into account when sit­
ing the flue terminal.
Fig.21
Flue outlets
J,K
T
U
N
R
M
I
I
A
D
E
C
I
F
S
I
F
J,K
B
L
A
A
G
H
H
I
1
PN-0000206
1
Tab.23
Flue positions marked
Terminal position with minimum distance
Key
Description
A (1)
Directly below an opening, air brick open­ 300
ing window etc.
32
require a flue terminal guard.
mm
Key
Description
mm
J
From a surface or boundary line facing 600
a terminal
7672024 - 1 - 03112016
5 Before installation
Key
Description
mm
B (1)
Above an opening, air brick, opening win­ 300
dow etc.
Key
Description
mm
K
From a terminal facing a terminal
(Horizontal flue)
1200
From a terminal facing a terminal (Ver­ 600
tical flue)
C (1)
Horizontally to an opening, air brick,
opening window etc.
300
L
From an opening in carport (e.g. door, 1200
window) into the dwelling
D (2)
Below gutters, soil pipes or drain pipes
25 (75)
M
Vertically from a terminal on the same
wall
1500
E (2)
Below eaves
25 (200)
N
Horizontally from a terminal on the
same wall
300
F (2)
Below balconies or car port roof
25 (200)
R
From adjacent wall to flue (vertical on­ 300
ly)
G (2)
From a vertical drain pipe or soil pipe
25 (150)
S
From an adjacent opening window
(vertical only)
1000
H (2)
From an internal or external corner
25 (300)
T
Adjacent to windows or openings on
pitched and flat roofs
600
I
Above ground, roof, or balcony level
300
U
Below windows or openings on pitch­
ed roofs
2000
(1) In addition, the terminal should be no nearer than 150mm to an opening in the building fabric formed for the purpose of accommodating
a built-in element such as a window frame.
(2) Only ONE 25mm clearance is allowed per installation. If one of the dimension D,E,F,G or H is 25mm then the remainder MUST be as
shown in brackets, in accordance with BS 5440–1.
Important
Under car ports we recommend the use of the plume displace­
ment kit. The terminal position must ensure the safe and nuisance
- free dispersal of combustion products.
If the terminal discharges onto a pathway or passageway, check that com­
bustion products will not cause a nuisance and that the terminal will not
obstruct the passageway.
If a terminal is less than 2 metres above a balcony, above ground or
above a flat roof to which people have access, then a suitable terminal
guard must be provided.
Fig.22
Property boundary
1
2
3
A
A*
2
Property boundary line
Terminal assembly
Top view rear flue
300mm minimum*
*Reduction to the boundary is possible down to 25mm but the flue deflec­
tor must be used.
Important
The distance from a fanned draught appliance terminal installed
parallel to a boundary may not be less than 300mm in accordance
with the diagram opposite.
3
1
PN-0000207
7672024 - 1 - 03112016
33
5 Before installation
Fig.23
Plume displacement kit
1
2
3
A
3
Opening window or door
Air inlet
Plume displacement kit
150mm minimum
Important
If fitting a Plume Displacement Flue Kit, the air inlet must be a
minimum of 150mm from any opening windows or doors.
Important
The Plume Displacement flue gas discharge terminal and air inlet
must always terminate in the same pressure zone i.e. on the same
facing wall.
2
1
A
PN-0000208
5.3.8
Fig.24
Horizontal flues
Horizontal flue/chimney systems
1
2
3
1
315mm to 500mm
Flue trims
This bend is equivalent to 1 metre
Total equivalent length = A+B+C+2x90° bends
Important
Horizontal flue extensions should always be installed with a fall of
at least 1.5° from the terminal to allow condensate to run back to
the boiler.
2
The standard telescopic flue is suitable only for horizontal termination ap­
plications. It allows for lengths between 315mm and 500mm from elbow to
terminal without the need for cutting. Extensions of 250mm, 500mm and
1m are available.
All fittings should be fully engaged. The approximate engagement is
40mm. Apply the lubricant supplied to the seal on each fitting to aid as­
sembly.
Tab.24
Maximum permissible equivalent flue lengths are:-
Horizontal concentric
3
C
A
60/100 Diameter
80/125 Diameter
10 metres
20 metres
Any additional "in line" bends in the flue system must be taken into consid­
eration.
B
3
Tab.25
(i)
(ii)
Their equivalent lengths are:-
Concentric pipes
135° bend
0.5 metres
93° bend
1.0 metres
The elbow supplied with the standard horizontal telescopic flue kit is not
included in any equivalent length calculations.
PN-0000209
Important
Flue length is measured from point (i) to (ii) as shown.
See
Read this section in conjunction with the Flue Installation Guide
supplied with the boiler. This document includes details of vertical
flue/chimney systems and plume displacement kits.
34
7672024 - 1 - 03112016
5 Before installation
Warning
SUPPORT - All flue systems MUST be securely supported at a
MINIMUM of once every metre & every change of direction. It is
recommended that every straight piece is supported irrespective
of length. Additional supports are available as accessories.
VOIDS - Consideration must be given to flue systems in voids and
the provision of adequate access for subsequent periodic visual
inspection.
5.3.9
Flue/chimney trim
The flexible flue trims supplied can be fitted on the outer and inner faces of
the wall of installation.
5.3.10
Fig.25
Terminal guard
1
Terminal guard
Ensure that no part of the white outer chimney duct is visible.
When codes of practice dictate the use of terminal guards Multifit accesso­
ry part no. 720627901 can be used
1
Important
This guard is not compatible with Flue Deflector referred to below.
There must be a clearance of at least 50mm between any part of the ter­
minal and the guard.
When ordering a terminal guard, quote the appliance name and model
number.
PN-0000210
The flue terminal guard should be positioned centrally over the terminal
and fixed as illustrated.
5.3.11
Fig.26
Flue deflector
1
1
Flue/chimney deflector
Flue deflector
Push the flue deflector over the terminal end. It may point upwards as
shown, or up to 45° either way from vertical. Secure the deflector to the
terminal with screws provided.
PN-0000211
5.3.12
Flue/chimney accessories
See
For full details of Flue Accessories (elbows, extensions, clamps
etc.) refer to the Flue Installation Guide supplied in the literature
pack.
5.4
Transport
This product should be lifted and handled by two people. When lifting al­
ways keep your back straight and wear protective equipment where nec­
essary. Carrying and lifting equipment should be used as required. e.g.
when install in a loft.
7672024 - 1 - 03112016
35
5 Before installation
5.5
Unpacking & initial preparation
5.5.1
Unpacking
Important
RISK ASSESSMENT - Before commencing the installation it is
recommended that the "Five Steps to Risk Assessment" docu­
ment published by the HSE is consulted, and an assessment per­
formed as described. GAS SUPPLY - The gas supply, gas type
and pressure must be checked for suitability before connection.
See
Handling, page 9 before unpacking or lifting the boiler.
Follow the procedure on the carton or see the diagrams below to unpack
the boiler.
Lift the boiler to a vertical position (1).
Remove the straps and the strip of tape (2)-(3)-(4).
Remove the accessories (5).
Remove the polystyrene by slipping it off upwards (6).
Remove the carton by pulling it upwards (7).
Snap off the rear part of the polystyrene at the bottom (8).
Important
Polystyrene base should be removed completely if fitting the boiler
into a space with minimum side clearances of 5mm each side.
If removing the polystyrene base the sealing caps can also be removed at
this stage.
Important
Care must be taken to avoid damage from any residual water in
the boiler
36
7672024 - 1 - 03112016
5 Before installation
Fig.27
Unpacking
1
2
3
4
5
6
7
8
PN-0000214
5.5.2
Fig.28
Template
1. After considering the location position the fixing template on the wall
ensuring it is level both horizontally and vertically.
2. Mark the position of the fixing slots for the wall bracket indicated on
the template.
3. Mark the position of the centre of the flue hole (rear exit). For side flue
exit, mark as shown.
4. If required, mark the position of the gas and water pipes. Remove the
template.
5. Cut the hole for the flue (minimum diameter 116mm).
6. Drill the wall as previously marked to accept suitable wall plugs. Se­
cure the wall bracket using appropriate fixing screws.
Clearance above 183
116 Dia Minimum
Aperture For
Flue Tube
50 MIN
Vertical Flue
Centre Line
Ø8
198
198
Side Clearance 5
Initial preparation
Side Clearance 5
View from under boiler
Wall
82.5
34
33.5
Heating
Flow
(22mm)
65
65
65
Hot Water
Outlet
(15mm)
Cold Water
Inlet
(15mm)
Combi Only
Not System
Combi Only
Not System
67.5
Heating
Return
(22mm)
32
Ø 22
65
Clearance below 250
PN-0000217
7672024 - 1 - 03112016
37
5 Before installation
Fig.29
Mounting the boiler
9
7. Using a spirit level ensure that the wall bracket is level before finally
tightening the screws
8. Lift the boiler by gripping "a" and "b" and hook the boiler onto the wall
bracket (9).
9. Remove the polystyrene by slipping it off downwards (10).
10. Remove the sealing caps from the pipes underneath the boiler
10
Warning
Some residual water may escape when removing the sealing
caps. Take precautions to avoid damage to components!
b
.
a
PN-0000216
5.6
Connecting diagrams
5.6.1
Fig.30
System filling circuit
D
C
A
B
C
D
E
C
Fig.31
Domestic hot water mains inlet
Central heating return
Stop valve
Double check valve
Temporary loop
A filling point connection on the central heating return pipework must be
provided to facilitate initial filling and pressurising and also any subsequent
water loss replacement/refilling.
E
A
Filling information
B
PN-0000212
Filling loop
A
B
Filling loop
Flow and return taps
A filling loop is supplied with the 424 and 428 models.
The filling method adopted must be in accordance with all relevant water
supply regulations and use approved equipment.
Your attention is drawn to:
for GB: Guidance G24.2 and recommendation R24.2 of the Water Regu­
lations Guide.
for IE: the current edition of I.S. 813 Domestic Gas Installations.
The sealed primary circuits may be filled or replenished by means of a
temporary connection between the circuit and a supply pipe, provided a
"Listed" double check valve or some other no less effective backflow pre­
vention device is permanently connected at the inlet to the circuit and the
temporary connection is removed after use.
B
A
PN-0000231
38
7672024 - 1 - 03112016
5 Before installation
5.6.2
Fig.32
Circuit plan
A
B
C
D
E
F
G
G
B
A
C
D
Domestic hot water circuit
Boiler
Expansion vessel
Check valve
Pressure reducer
Stop tap
To hot tap
Other tap outlets
All DHW circuits, connections, fittings, etc. should be fully in accordance
with relevant standards and water supply regulations.
F
E
Your attention is drawn to:
PN-0000215
for GB: Guidance G17 to G24 and recommendation R17 to R24 of the
Water Regulations Guide.
for IE: the current edition of IS 813 Domestic Gas Installations.
The Water Regulations recommendations for England and Wales prohibits
backflow from appliances into the wholesome water supply due to thermal
expansion. However this type of instantaneous combination boiler, with
less than 15 litres of stored capacity, does not require any backflow pre­
vention device as any thermal expansion is accommodated within the ap­
pliance. It is possible in certain circumstances that other cold water de­
mands (e.g. washing machines, flushing of WCs) may affect the DHW
function of the boiler. In these instances the fitting of a backflow prevention
device and expansion vessel is recommended.
Important
In instances where the mains water supply incorporates a non-re­
turn backflow prevention device, or any other device that includes
one*, it is possible for a build-up of pressure to occur. This may re­
sult in damage to the boiler and other appliances. To prevent
damage to the boiler it is strongly recommended that a suitable
mini expansion vessel is fitted on the mains water inlet between
the boiler and the non-return device.
*(The manufacturer of the device should be consulted if there is
any doubt regarding the presence of a non-return feature).
Even in circumstances where a non-return device is not fitted any
future modifications to the mains inlet (e.g. fitting of a water meter)
should be considered and an expansion vessel fitted. Baxi cannot
accept any responsibility for damage to the boiler if these recom­
mendations are not followed.
The boiler’s maximum working mains pressure is 8 bar, therefore all pipe­
work, connections, fittings, etc. should be suitable for pressures in excess
of 8 bar. A pressure reducing valve must be fitted for pressures in excess
of 8 bar. The manufacturer of any outlet fittings, such as a shower valve,
may require a lower maximum pressure. The pressure reduction must take
account of all fittings connected to the DHW system.
7672024 - 1 - 03112016
39
6 Installation
6
Installation
6.1
General
Installation must be carried out in accordance with the prevailing regula­
tions, codes of practice and the recommendations in this manual.
Danger
If the boiler is installed in a compartment do not use it for storage
purposes. Do not obstruct any purpose provided ventilation open­
ings.
Caution
Where the boiler is sited in an unheated enclosure provision must
be made to protect against frost, e.g. frost thermostat, pipe ther­
mostat.
Important
If the boiler stand-off kit has been used the copper tails are rever­
sible and can be used here.
Ensure the sealing caps are removed from the boiler connections under
the boiler (including the condensate trap).
Important
A small amount of water may drain from the boiler once the caps
are removed.
Remove the taps, elbow and sealing washers from the fitting kit.
Connect the appropriate tap to the heating flow and return pipework, gas
supply and mains cold inlet. The elbow must be connected to the DHW
flow pipe.
Using the sealing washers provided connect the taps and elbow to the
boiler.
Ensure all joints are tight.
6.2
Assembly
6.2.1
Fig.33
Pressure relief pipe connection
Fitting the pressure relief discharge pipe
1. Remove the discharge pipe from the kit.
2. Determine the routing of the discharge pipe in the vicinity of the boil­
er. Make up as much of the pipework as is practical, including the
discharge pipe supplied.
Important
Make all soldered joints before connecting to the pressure relief
valve. Do not adjust the position of the valve. The discharge pipe
must be installed before pressurising the system.
PN-0000283
40
3. The pipework must be at least 15mm diameter and run continuously
downwards to a discharge point outside the building.
4. Firmly engage the flange on the pipe into the pressure relief valve
outlet grommet, ensuring it is pushed fully in.
5. Complete the discharge pipework and route it to the outside dis­
charge point.
6. The pipework must be clipped at suitable intervals to support it, com­
mencing as close to the boiler as possible.
7672024 - 1 - 03112016
6 Installation
6.2.2
Connecting the condensate drain
1. Remove the blanking cap, and using the straight rubber coupling
supplied, connect the condensate drain pipework to the boiler con­
densate trap outlet pipe.
See
Ensure the discharge of condensate complies with any national or
local regulations in force (see HHIC recommendations).
See
Condensate drain, page 30.
2. The straight rubber coupling will accept 21.5mm (3/4 in) plastic over­
flow pipe which should generally discharge internally into the house­
hold drainage system. If this is not possible, discharge into an out­
side drain is acceptable.
3. The boiler condensate trap should be primed by pouring approxi­
mately 300ml of water into the flue spigot. Do not allow any water to
fall into the air inlet.
6.3
Air supply/flue gas connections
6.3.1
Fig.34
Telescopic flue
Connecting the flue/chimney
HORIZONTAL TELESCOPIC FLUE (concentric 60/100)
1
2
3
1
315mm to 500mm
Connection assembly
Terminal assembly
There are two telescopic sections, the terminal assembly and the connec­
tion assembly, a roll of sealing tape and two self tapping screws. A 93° el­
bow is also supplied.
3
2
PN-0000218
The two sections can be adjusted to provide a length between 315mm and
500mm when measured from the flue elbow (there is 40mm engagement
into the elbow).
1. Locate the flue elbow on the adaptor at the top of the boiler. Set the
elbow to the required orientation.
Important
The flue elbow is angled at 93° to ensure a fall back to the boiler.
Fig.35
2. Measure the distance from the outside wall face to the elbow. This
dimension will be known as " X" .
3. If the distance from the flue elbow to the outside face of the wall is
less than 250mm the connection assembly can be discarded and
the terminal assembly fitted directly into the elbow.
4. In instances where the dimension " X" is between 250mm and
315mm it will be necessary to shorten the terminal assembly by
careful cutting to accommodate walls of these thicknesses.
Flue dimension X
X
X
PN-0000219
7672024 - 1 - 03112016
41
6 Installation
Fig.36
Flue dimension Y
1
4
2
Y
1
3
PN-0000220
Fig.37
Attaching the flue
C
4
4
A
3
B
2
1
5
5. To dimension " X" add 40mm. This dimension to be known as "Y" .
1
TOP label
2
Sealing tape
3
Securing screw
4
Peak to be uppermost
6. Adjust the two telescopic sections to dimension "Y" and seal the joint
with the tape provided. Ensure that the labels marked "TOP" on the
terminal and connection assemblies are uppermost.
7. Using the clearance holes in the connection assembly secure it to
the terminal assembly using the screws supplied with the telescopic
flue.
8. Remove the flue elbow and insert the flue through the hole in the
wall. Fit the flue trims if required, and refit the elbow to the boiler
adaptor, ensuring that it is pushed fully in. Secure the elbow with the
screws supplied in the boiler fitting kit.
1
Flue elbow
2
Boiler adaptor
3
Telescopic flue
4
Flue trim
5
Securing screw
A
Apply the lubricant supplied for ease of assembly (do not use
any other type). Ensure flue is fully engaged into elbow.
B
Apply the lubricant supplied for ease of assembly (do not use
any other type). Ensure elbow is fully engaged into boiler
adaptor.
C
Peak to be uppermost
9. Draw the flue back through the wall and engage it in the elbow. It
may be necessary to lubricate to ease assembly of the elbow and
flue.
10. Ensure that the terminal is positioned with the slots to the bottom.
Secure to the elbow with the screws supplied with the telescopic
flue.
Important
It is essential that the flue terminal is fitted as shown to ensure
correct boiler operation and prevent water entering the flue.
PN-0000221
11. Make good between the wall and air duct outside the building, ap­
propriate to the wall construction and fire rating.
12. If necessary fit a terminal guard.
Important
There must be no part of the air duct (white tube) visible outside
the property.
6.4
Electrical connections
See
Electrical supply, page 25 for details of the electrical supply.
Warning
Check that the total nominal consumption of the accessories con­
nected to the appliance is less than 1 amp. If it is higher, a relay
must be installed between the accessories and the electronic
board.
6.4.1
Panel removal to make electrical connection
Remove the plastic protective coating from the front of the boiler.
Unscrew the two screws retaining the electrical cover at the bottom of the
front panel and then remove the cover.
42
7672024 - 1 - 03112016
6 Installation
6.4.2
Fig.38
Electrical connections
Electrical connections of the boiler
Access the connection board located below the control panel to make the
electrical connections by:
1. Fully unscrewing the two screws retaining the electrical cover at the
bottom of the front panel and then remove the cover.
2. Connect the electrical power supply to the X1 terminal on the con­
nection board as shown on the label located on the inside of the
electrical cover. Route the cables to the rear using the integral chan­
nel guides. Additional cable ties can be used if 5–core cable is used.
Important
The blue X1 Mains terminal block can be removed to ease the ac­
cess for wiring.
B
TIMER
Bl
W Br
Gn Bk R
Bk Br
R
Gy
Bl
Bl
W Vt
Gy
12 34 5
1 2 34 567
12
X12
X11
X10
1
X5
1 2 3
X3
X2
B
J
X9
X13
X8
OT
X14 X7
OS
L-BUS
On
G/Y
Br
Bk
Br
X1 MAINS
X6
X4
RT
F2
0.5A
N L
230V - 50Hz
X1
X4
X6
X7
X8
X9
X13
X14
Electrical power supply 230V~50Hz
230V Room thermostat (remove the link)
Not used
Not used
On/Off — R-Bus — Low voltage/voltage free Room thermostat (re­
move the link)
Service connection (PC)
L-Bus connection
Outside sensor (OS) connection
J
X14 – 1. Outside sensor
X14 – 2. Common
Dip-switch
SERVICE
Off
321
PN-0000274
J1. Maximum heating temperature: OFF = 80°C = 45°C (floor
system)
J2. OFF = Maximum output (heating) — ON = Boiler output 50%
(heating)
J3. DO NOT ADJUST!
See
Electrical diagram, page 20 for more information.
6.4.3
Connecting a room thermostat
The terminals can be accessed by removing the electrical cover as descri­
bed in Electrical connections of the boiler, page 43.
230V Room Thermostat
When using a 230V Room Thermostat it must be connected to Terminal
X4 on circuit board B. See diagram.
The X4 link wire must be removed from the terminal.
Important
The X4 terminal block for the 230V Room Thermostat can be re­
moved to ease the access for wiring.
Low Voltage/Voltage Free Room Thermostat
These connections are not polarity sensitive.
When using a Low voltage/Voltage free Open Therm type room thermostat
it must be connected to Terminal X8 on connection board B. See diagram.
The X8 link wire must be removed from the terminal.
Replace the electrical cover and secure with the 2 screws.
7672024 - 1 - 03112016
43
6 Installation
6.5
Filling the installation
6.5.1
Flushing the system
Flush thoroughly and treat the system according to guidance given in BS
7593.
6.5.2
Fill the installation
1. A filling loop is supplied with the 424/428 models. It can be fitted to
the cold mains inlet and the CH return isolation taps.
2. Fill the installation using approved equipment and in accordance
with all relevant water supply regulations.
Important
Your attention is drawn to:
for GB: Guidance G24.2 and recommendation R24.2 of the Wa­
ter Regulations Guide.
for IE: The current edition of IS 813 “Domestic Gas Installa­
tions”.
3. The sealed primary circuits may be filled or replenished by means of
a temporary connection between the circuit and a supply pipe, provi­
ded a "Listed" double check valve or some other no less effective
backflow prevention device is permanently connected at the inlet to
the circuit and the temporary connection is removed after use.
4. Fill or replenish the sealed primary circuits by means of a temporary
connection between the circuit and a supply pipe:
— Permanently connect a "Listed" double check valve or some other
no less effective backflow prevention device at the inlet to the circuit.
— Remove the temporary connection after use
44
7672024 - 1 - 03112016
7 Commissioning
7
7.1
Commissioning
General
Reference should be made to BS:EN 12828, 12831 & 14336 when com­
missioning the boiler. Ensure that the condensate drain trap has been
primed.
At the time of commissioning, complete all relevant sections of the Bench­
mark Checklist at the rear of this publication.
Open the mains water supply to the boiler and all hot water taps to purge
the DHW system.
Ensure that the filling loop is connected and open, then open the heating
flow and return valves on the boiler. Ensure that the cap on the automatic
air vent on the pump body is opened.
The system must be flushed in accordance with BS 7593 and the flushing
agent manufacturer’s instructions.
Pressurise the system to 1.5 bar then close and disconnect the filling loop.
Test for gas tightness, turn the gas supply on and purge according to in
GB BS 6891 and in IE I.S. 813 "Domestic Gas Installations" .
7.2
Checklist before commissioning
7.2.1
Preliminary electrical checks
Prior to commissioning the boiler preliminary electrical system checks
should be carried out.
These should be performed using a suitable meter, and include checks
for Earth Continuity, Resistance to Earth, Short Circuit and Polarity.
7.2.2
Checks
Check:
That the boiler has been installed in accordance with these instructions.
The integrity of the flue system and the flue seals.
The integrity of the boiler combustion circuit and the relevant seals.
That the condensate trap has been primed.
That the electrical cover has been refitted.
7672024 - 1 - 03112016
45
7 Commissioning
7.3
Commissioning procedure
7.3.1
Fig.39
Initialisation process
De-Aeration function
Before turning on the power to the boiler, rotate the Central Heating con­
trol knob fully clockwise.
The purpose of the function is to remove as much air as possible from the
heating system. It operates automatically on the boiler’s first power up and
lasts approximately 5 minutes.
Turn on the power to the boiler. The display shows an initialisation se­
quence briefly before displaying t.17 to indicate the sequence has started.
At the end of the de-aeration process the flame symbol is seen in the dis­
play whilst the boiler does a flame ionisation check.
A
Initialisation sequence before de-aeration starts
Important
If during this first commissioning process the power to the boiler is
interrupted the de-aeration function will restart automatically.
A
Caution
Only the initial de-aeration process during commissioning is per­
formed automatically. Any subsequent de-aeration carried out, for
example after a system drain down, must be done manually.
To start the process manually, press the RESET button for approximately
5 seconds and release. The display will show dAf briefly and then t.17 to
indicate that the process has started.
Caution
If the power is lost to the boiler during a manual de-aeration the
process does NOT restart automatically! Re-establish the power
and manually restart the de-aeration.
PN-0000224
7.4
Gas settings
7.4.1
Gas meter to valve
If the pressure drops are greater than shown in the diagram oppo­
site, a problem with the pipework or connections is indicated. Per­
missible pressure drop across system pipework ≤ 1mbar.
VENT
RQ
ADJ.
A
P. OUT
Fig.40
Check the operational (working gas inlet pressure and
gas rate)
EV2
17-21 mbar
1
2
3
EV1
4
18-22 mbar
Important
The system MUST be cold to ensure the boiler is operating under
full demand. To obtain an accurate measurement on smaller ca­
pacity systems it may be necessary to open one or more hot taps
and remove the diverter valve motor in order to maintain the boiler
output.
19-23 mbar
A
PN-0000269
46
7672024 - 1 - 03112016
7 Commissioning
Fig.41
Gas inlet test point
A
Gas inlet test point
1. With the boiler operating in the maximum rate condition check that
the operational (working) gas pressure at the inlet gas pressure test
point is in accordance with BS 6798 & BS 6891. This must be AT
LEAST 17mb !
2. Ensure that this inlet pressure can be obtained with all other gas ap­
pliances in the property working. The pressure should be measured
at the test point on the gas cock.
3. Measure the gas rate — With any other appliances & pilot lights
turned OFF the gas rate can be measured. It should be:-
A
PN-0000275
Tab.26
7.4.2
Natural gas
224 model
2.61 m3/h
228 model
3.06 m3/h
424 model
2.61 m3/h
428 model
3.06 m3/h
Checking combustion - chimney sweep mode
See
If the appliance cannot be operated on central heating for more
than 10 minutes without reaching maximum temperature refer to
Combustion check on small heating systems, page 74.
The case front panel must be fitted when checking combustion.
Ensure the system is cold and the gas and electric supplies are turned
on.
Fig.42
Flue adaptor test points
Important
The person carrying out a combustion measurement should have
been assessed as competent in the use of a flue gas analyser and
the interpretation of the results.
1
2
Combustion test point
Incoming air for combustion test point
1
2
PN-0000233
Important
Allow the combustion to stabilise before inserting the Combustion
Analyser Probe into the Test Point (1). This will prevent saturation
of the analyser.
The combustion must be measured and recorded at the Maximum and
Minimum heat inputs.
7672024 - 1 - 03112016
47
7 Commissioning
Fig.43
Chimney sweep procedure
Measuring the combustion
Important
The system MUST be cold to ensure the boiler is operating under
full demand.
A
1. Turn the Central Heating and Domestic Hot Water control knobs fully
clockwise.
2. Activate the Chimney Sweep mode by pressing the Chimney Sweep
button for 3 seconds (A). The display will show the activation se­
quence (B) then a "P" with 3 bars alongside it alternating with the
current water temperature (C). This indicates the Maximum Domes­
tic Hot Water rate.
3. Check the CO and CO2 levels at the Maximum rate and record the
result in the Benchmark log at the back of this manual.
4. Press the Chimney Sweep button (A) again to set the boiler to its
minimum rate. The display shows a "P" with 1 bar alongside it alter­
nating with the current water temperature (D).
5. Check the CO and CO2 levels at the Minimum rate and record the
result in the Benchmark log at the back of this manual.
6. A further press of the Chimney Sweep button (A) will set the boiler to
its Maximum Central Heating Rate. The display shows a "P" with 2
bars alongside it alternating with the current water temperature (E).
7. To exit the Chimney sweep function press and hold the Chimney
sweep button for approximately 3 seconds and release.
8. Replace the plug in the flue adaptor test point. Fig. 42.
B
C
See
If the appliance cannot be operated on central heating for more
than 10 minutes without reaching maximum temperature refer to
Combustion check on small heating systems, page 74.
A
D
E
PN-0000227
48
7672024 - 1 - 03112016
7 Commissioning
Fig.44
Combustion procedure
Set Boiler to Maximum Rate
Allow the combustion to
stabilise. Do not insert probe
to avoid ‘flooding’ the analyser.
Verify Flue Integrity
Indication that products of
combustion & inlet air are
mixing - further
investigation is required.
Check all flue components
are correctly assembled,
fixed & supported. Check
the flue & terminal are
unobstructed.
Is O2 ≥ 20.6% and
CO2 < 0.2% ?
Perform Flue Integrity
Combustion Check
Insert the analyser probe into
the air inlet test point, allowing
the reading to stabilise.
No
Is O2 ≥ 20.6% and
CO2 < 0.2% ?
Yes
Yes
No
Check CO & Combustion
Ratio at Maximum Rate
Whilst the boiler is still
operating at maximum insert
the analyser probe into the
flue gas test point, allowing
the reading to stabilise.
Is CO < 350ppm
and CO/CO2 ratio
< 0.004 ?
Yes
No
TURN APPLIANCE OFF !
Call 0344 871 1545 for
advice.
The appliance MUST NOT
be commissioned until all
problems are identified
and resolved.
Verify Integrity of Seals
Check all burner seals,
internal flue seals, door &
case seals. Replace any
seals that appear unsound.
Is CO < 350ppm
and CO/CO2 ratio
< 0.004 ?
No
TURN APPLIANCE OFF !
Call 0344 871 1545 for advice.
The appliance MUST NOT be
commissioned until all
problems are identified and
resolved.
If commissioning cannot be
fully completed the appliance
must be disconnected from the
gas supply in accordance with
the GSIUR.
Note: Check & record the CO
& combustion ratio at both
maximum & minimum rates
before calling 0344 871 1545.
Set Boiler to Minimum Rate
Allow the combustion to
stabilise. Do not insert probe
to avoid ‘flooding’ the analyser.
Check CO & Combustion
Ratio at Minimum Rate
Whilst the boiler is
operating at minimum insert
the analyser probe into the
flue gas test point, allowing
the reading to stabilise.
Yes
No
Is CO < 350ppm
and CO/CO2 ratio
< 0.004 ?
Yes
BOILER OPERATING
SATISFACTORILY. NO
FURTHER ACTION
REQUIRED
Ensure test points are capped,
the boiler case front panel is
correctly fitted & secured and
all other commissioning
procedures completed.
Complete the ‘Benchmark’
Checklist, recording the CO &
combustion ratio readings as
required.
PN-0000222
7672024 - 1 - 03112016
49
7 Commissioning
7.5
Configuring the system
7.5.1
System draining
If at any time after installation it is necessary to drain and refill the central
heating system (e.g. when replacing a radiator) the De-Aeration function
must be activated to avoid air being trapped in the system.
See
De-Aeration function, page 46.
Once De-Aeration is complete recommission the boiler and check that the
inhibitor concentration is sufficient.
7.6
Final instructions
7.6.1
Handover
1. Carefully read and complete all sections of the Benchmark Commis­
sioning Checklist at the rear of this publication that are relevant to
the boiler and installation. These details will be required in the event
of any warranty work.
Important
The warranty will be invalidated if the Benchmark section is in­
complete.
2. The publication must be handed to the user for safe keeping and
each subsequent regular service visit recorded.
3. Hand over the User’s Operating, Installation and Servicing Instruc­
tions, giving advice on the necessity of regular servicing.
4. For IE, it is necessary to complete a "Declaration of Conformity" to
indicate compliance with I.S. 813. An example of this is given in I.S.
813 "Domestic Gas Installations" . This is in addition to the Bench­
mark Commissioning Checklist.
5. Set the central heating and hot water temperatures to the require­
ments of the user. Instruct the user in the operation of the boiler and
system.
6. Instruct the user in the operation of the boiler controls.
7. Demonstrate to the user the action required if a gas leak occurs or is
suspected. Show them how to turn off the gas supply at the meter
control, and advise them not to operate electric light or power
switched, and to ventilate the property.
8. Show the user the location of the system control isolation switch,
and demonstrate its operation.
9. Advise the user that they may observe a plume of vapour from the
flue terminal, and that it is part of the normal operation of the boiler.
50
7672024 - 1 - 03112016
8 Operation
8
Operation
8.1
Use of the control panel
8.1.1
Control
The controls are operated by the buttons and knobs shown.
Fig.45
Operating the controls
1
1
2
3
2
Central heating water temperature control
Domestic Hot Water temperature control
Reset button
3
PN-0000289
8.2
Start up
If there is no power to the boiler, switch on at the fused spur unit and en­
sure that the time control is in the on position and any other controls (e.g.
room thermostat) are calling for heat.
Press the RESET button once to bring the boiler out of Standby mode.
The boiler will begin its start sequence. This procedure performs a series
of tests, after which the installation is purged (this takes approximately five
minutes).
8.3
Shutdown
Isolate the mains power supply at the fused spur unit.
Isolate the gas supply at the boiler valve.
Protect the boiler from frost.
Important
The boiler is not protected against frost once it has been shut
down.
8.4
Frost protection
Where possible, draining the system should be avoided. If the system is to
be unused during winter months several precautions must be taken:
A suitable antifreeze solution added to the system.
Any parts of the system that are in unheated areas of the dwelling fitted
with a device such as a pipe thermostat or frost thermostat.
Power must remain supplied to the boiler and controls.
Gas must remain supplied to the boiler.
The boiler pump will operate if the system temperature drops below 7°C. If
the temperature falls to 4°C the burner will ignite and remain lit until the
temperature reaches 10°C. At this temperature the burner will extinguish
but the pump will continue to operate for 15 minutes. This feature will pro­
tect the boiler and to some extent adjacent parts of the system but addi­
tional devices must be incorporated to guarantee frost protection.
7672024 - 1 - 03112016
51
9 Settings
9
Settings
9.1
Functions
The operating functions of the boiler have been factory set to suit most
systems. See table below for a list of display functions.
See
Accessing the information menu, page 69
for further information.
9.2
Tab.27
Information menu
Information list
Information
Description
Status
Sub-status
°C
Heating water temperature (°C)
The
°C
symbol flashes
Domestic hot water temperature (°C)
The
symbol flashes
If no domestic hot water sensor connected: display — — —
°C
Outside temperature (°C)
The
symbol flashes.
Burner status
Energy meter on the heating water circuit
The
symbol flashes.
The displayed value flashes.
Energy meter on the domestic hot water circuit
The
symbol flashes.
The displayed value flashes.
Information on the boiler not available
52
7672024 - 1 - 03112016
10 Maintenance
10 Maintenance
10.1
General
Warning
When changing components ensure that both the gas and electri­
cal supplies to the boiler are isolated before any work is started.
When the component has been changed recommission the boiler.
Always examine any seals or gaskets, replacing where necessary.
The case front panel MUST seal effectively against the boiler side
panels.
For reasons of safety and economy, it is recommended that the boiler is
serviced annually. Servicing must be performed by a competent person in
accordance with BS 7967-4.
After servicing, complete the relevant Service Interval Record section of
the Benchmark Commissioning Checklist at the rear of this publication.
Important
During routine servicing, and after any maintenance or change of
part of the combustion circuit, the following must be checked:The integrity of the complete flue system and the flue seals by checking
air inlet sample to eliminate the possibility of recirculation. O2 ≥ 20.6% &
CO2< 0.2%
The integrity of the boiler combustion circuit and relevant seals.
The operational gas inlet pressure and the gas rate.
The combustion performance as described in "Check the Combustion
Performance" below.
Competence to carry out checking combustion performance BS 6798
"Specification for Installation & Maintenance of Gas Fired Boilers not ex­
ceeding 70kWh" advises that:The person carrying out a combustion measurement should have been
assessed as competent in the use of a flue gas analyser and the inter­
pretation of the results.
The flue gas analyser used should be one meeting the requirements of
BS 7927 or BS-EN50379-3 and be calibrated in accordance with the an­
alyser manufacturers’ requirements.
Competence can be demonstrated by satisfactory completion of the
CPA1 ACS assessment, which covers the use of electronic portable
combustion gas analysers in accordance with BS 7967, Parts 1 to 4.
Check the Combustion Performance (CO/CO2 ratio)
Set the boiler to operate at maximum rate.
See
Checking combustion - chimney sweep mode, page 47 for details.
Remove the plug from the flue sampling point, insert the analyser probe
and obtain the CO/CO2 ratio. This must be less than 0.004. If the combus­
tion reading (CO/CO2 ratio) is greater than this, and the integrity of the
complete flue system and combustion circuit seals has been verified, and
the inlet gas pressure and gas rate are satisfactory either:Perform the "Standard Inspection and Maintenance" .
Perform "Setting the Gas Valve" .
Replace and set the gas valve.
7672024 - 1 - 03112016
53
10 Maintenance
10.2
Standard inspection and maintenance operations
10.2.1
Periodic check and maintenance procedure
Warning
Before performing any operation, make sure the boiler is not pow­
ered on. Once the maintenance operations are complete, reset
the original boiler operating parameters if they were changed.
Warning
Wait for the combustion chamber and pipes to cool down.
Important
The appliance must not be cleaned using abrasive, aggressive
and/or easily flammable substances (e.g. petrol or acetone).
The following checks must be performed every year in order to ensure effi­
cient boiler operation:
1. Check the appearance and seal of the gaskets in the gas circuit and
the combustion circuit;
2. Check the condition and correct position of the flame detection and
ignition electrode;
3. Check the condition of the burner and that it is correctly fastened;
4. Check for any impurities located inside the combustion chamber. To
do so, use a vacuum cleaner or the cleaning kit available as an ac­
cessory;
5. Check the pressure of the heating system;
6. Check the pressure of the expansion vessel;
7. Check that the fan is working correctly;
8. Check that the intake and exhaust pipes are not obstructed;
9. Check for any impurities inside the siphon;
10.2.2
Checking the water pressure
In order for the boiler to operate correctly, the pressure of the water in the
heating circuit must be between 1.0 and 1.5 bar. Restore the water pres­
sure if necessary.
10.2.3
Checking the expansion vessel
Check the expansion vessel and replace it if necessary. Check its pre­
charge every year and restore the pressure to 1 bar if necessary.
10.2.4
Checking the automatic air vent
Check that the pump venting valve is working. In the event of a leak, re­
place the valve.
10.2.5
Checking the burner and cleaning the heat exchanger
1. Isolate the unit from the gas & electrical supplies.
2. Remove the front panel.
3. Remove the silencer.
Important
Reposition the silencer inside the boiler before refitting the air-gas
unit.
4. Open the air/gas cover and remove all the connectors from the PCB.
5. Close the air/gas cover.
6. Completely remove the air/gas and burner/unit by unscrewing the
four M6 nuts and undoing the 3/4” nut below the gas valve.
7. Check that the detection/spark electrode is not worn. Replace the
electrode if necessary.
54
7672024 - 1 - 03112016
10 Maintenance
8. Check the condition of the burner, the gasket and the insulation
board.
9. Any loose deposits in the heat exchanger should be removed using
a vacuum cleaner.
10. A brush with plastic bristles can be used to dislodge any stubborn
deposits, which should then also be removed by vacuum.
11. Do not use any chemicals to clean the heat exchanger.
12. The burner does not require any maintenance as it is self-cleaning.
Check that there are no cracks and/or other damage on the surface
of the burner. If the burner is damaged, replace it.
13. Reassemble in reverse order.
10.3
Specific maintenance instructions
Warning
When changing components ensure that both the gas and electri­
cal supplies to the boiler are isolated before any work is started.
When the component has been changed recommission the boiler.
Always examine any seals or gaskets, replacing where necessary.
The case front panel MUST seal effectively against the boiler side
panels.
Fig.46
Remove front panel
To remove the case front panel proceed as follows:
Remove the two screws retaining the electrical cover.
Remove the electrical cover.
Disengage the two clips on the case front panel and lift the panel slightly
to remove it from the lip on top of the case.
PN-0000235
10.3.1
Fig.47
Removing the detection/spark igni­
tion electrode
Detection/spark ignition electrode
1. Disconnect the electrode lead and earthing cable.
2. Using a T15 Torx key, remove the retaining screws securing the
electrode to the combustion chamber door and remove the elec­
trode, noting its orientation.
3. Fit the new electrode with the sealing gasket.
4. Reassemble in reverse order.
PN-0000236
7672024 - 1 - 03112016
55
10 Maintenance
10.3.2
Fig.48
Removing the NTC flue sensor
NTC flue sensor
1. Turn the sensor 90° anticlockwise to remove — it is a bayonet con­
nection.
2. Ease the retaining tab on the sensor away and disconnect the elec­
trical plug.
3. Fit new sensor and reassemble in reverse order.
PN-0000237
10.3.3
Fig.49
Removing the flow and return sen­
sors
Flow and return sensors
There is one sensor on the flow (red wires) and one sensor on the return
(black wires).
1. Remove the air/gas unit.
See
Air/gas unit, page 57 to remove.
2. After noting the position prise the sensor clip off the pipe and discon­
nect the plug.
3. Connect the plug to the new sensor and ease the clip onto the pipe
in its original position.
PN-0000249
10.3.4
Fig.50
Removing the safety overheat ther­
mostat
Safety overheat thermostat
1. Pull the two spade connections off the safety overheat thermostat.
2. Prise the thermostat clip with the safety overheat thermostat off the
pipe
3. Fit new safety thermostat on the pipe using heat-sink paste.
4. Connect the two spade connections to the safety overheat thermo­
stat ensuring that they are pushed fully on.
PN-0000250
10.3.5
Fig.51
HMI removal
1. Remove the screws from the link/timer
2. Hinge the control box downwards.
3. Disengage the optional timer plug and ease the cable out of its
housing.
4. Unclip the back cover of the control box and remove it.
5. Unplug the wire harness on the HMI control.
6. Release the clips securing the HMI control and remove it.
1
1
HMI control
2
2
PN-0000287
56
7672024 - 1 - 03112016
10 Maintenance
7. Fit the new HMI control and reassemble in reverse order ensuring all
plugs and cables are seated correctly.
Important
Ensure that wiring is correctly routed with no wires trapped during
reassembly.
10.3.6
Fig.52
Removing the burner
Burner/combustion chamber door assembly
1. Remove the detection/spark electrode.
See
Detection/spark ignition electrode, page 55
2. Hinge the control box down.
3. Hinge down the air/gas cover and disconnect all wiring plugs from
the PCB, noting their positions. Close the air/gas cover.
4. Using a 10mm spanner/socket, undo the 4 nuts holding the combus­
tion chamber door cover to the heat exchanger.
5. Undo the gas valve nut (30mm A/F).
6. Draw the combustion chamber/burner door assembly with the
air/gas unit away.
7. Remove the two Torx T30 screws holding the combustion chamber/
burner door assembly to the air/gas unit and disengage the tab on
the cover from the air/gas unit.
8. Fit new combustion chamber/burner door assembly to the air/gas
unit and reassemble in reverse order.
PN-0000247
10.3.7
Fig.53
Removing the air/gas unit
Air/gas unit
1. Disconnect the electrode lead and earthing cable.
2. Hinge the control box down.
3. Hinge down the air/gas cover and disconnect all wiring plugs from
the PCB, noting their positions. Close the air/gas cover.
4. Disconnect the silencer from behind the air/gas unit.
5. Undo the gas valve nut.
6. Remove the two Torx T30 screws securing the air/gas unit to the
burner combustion chamber door assembly.
7. Push the flexible gas pipe downwards and ease the air/gas unit
away from the burner combustion chamber door assembly.
8. Fit the new air/gas unit to the burner combustion chamber door as­
sembly and reassemble in reverse order.
Important
Ensure the silencer is correctly positioned.
Setting the gas valve
PN-0000246
7672024 - 1 - 03112016
Important
The CO2 must only be checked and adjusted to set the valve if a
suitable calibrated combustion analyser is available, operated by a
responsible person.
57
10 Maintenance
Fig.54
Adjusting the gas valve
C
1
1
A
B
C
D
Minimum rate (offset) adjustment screw.
Maximum rate adjustment screw.
Burner gas pressure outlet.
Gas supply pressure outlet.
B
Important
The case front panel must be fitted when checking combustion.
2
Run the boiler for several minutes before checking the CO and CO2. To
do this it is necessary to operate the boiler in Chimney sweep mode. En­
sure the boiler is at Maximum rate.
Insert the test probe in the flue sample point and allow the reading to
stabilise.
A
2
D
PN-0000234
See
Checking combustion - chimney sweep mode, page 47. If the ap­
pliance cannot be operated on central heating for more than 10
minutes without reaching maximum temperature refer to Combus­
tion check on small heating systems, page 74.
The CO2 at MAXIMUM rate should be 9% +0.4, –0.2. Alter the CO2 if nec­
essary by adjusting the gas valve.
Use the Maximum rate adjustment screw (B) to alter the CO2. Turn anticlockwise (B1) to increase the CO2 or clockwise (B2) to reduce the CO2.
Important
Do not turn the adjustment screw more than 1/8 of a turn at a
time. Allow the analyser reading to settle before any further adjust­
ment.
Set the boiler to Minimum rate and check the CO2. The CO2 at MINI­
MUM rate should be 8.5% +0.1, –0.4. Alter the CO2 if necessary by ad­
justing the gas valve.
Use the Minimum rate adjustment screw (A) to alter the CO2. Turn
clockwise (A2) to increase the CO2 or anti-clockwise (A1) to decrease
the CO2.
Check the combustion performance (CO/CO2 ratio). This must be less
than 0.004.
Important
If the CO2 is reset at minimum rate it must be rechecked at maxi­
mum rate again and adjusted if required. If the CO2 is reset at
maximum rate it must be rechecked at minimum rate and adjusted
if required.
Press the Chimney sweep button for 3 seconds to exit the function.
Refit the sampling point plug and ensure there is no leakage of prod­
ucts.
58
7672024 - 1 - 03112016
10 Maintenance
10.3.8
Fig.55
Removing the insulation
Insulation
1. Remove the Detection/spark ignition electrode.
See
Detection/spark ignition electrode, page 55.
PN-0000244
2. Hinge the control box down.
3. Hinge down the air/gas cover and disconnect all wiring plugs from
the PCB, noting their positions. Close the air/gas cover.
4. Undo the nuts holding the combustion chamber/burner door cover to
the heat exchanger.
5. Undo the gas valve nut.
6. Draw the combustion chamber/burner door with the air/gas unit
away.
7. Remove the cover insulation piece.
8. Fit the new insulation piece carefully over the burner and align it with
the slot for the electrode.
9. If the rear insulation requires replacement, remove it and all debris
from the heat exchanger.
10. Examine the cover seal and replace if necessary. Reassemble in re­
verse order.
10.3.9
Fig.56
Heat exchanger location bracket
Heat exchanger
1. Remove the boiler front panel.
2. Hinge down the controls door.
Warning
Ensure all wiring and electronics are protected before draining
down.
3.
4.
5.
6.
7.
8.
9.
Close the flow and return isolation taps.
Drain the primary circuit using the drain point provided.
Remove the flue thermistor.
Remove the condensate trap by lifting clear and pulling forward.
Disconnect the flow and return overheat thermistor.
Disengage the wires from the securing clip and move to one side.
Hinge down the air/gas cover and disconnect the wiring from the
PCB. Remove the air gas unit.
10. Remove the flow pipe by disengaging the clips and easing the pipe
down.
PN-0000285
Warning
Care must be taken to avoid damage due to residual water in the
heat exchanger.
11. Remove the return pipe by disengaging the clip to the heat exchang­
er and the screw at the rear of the pump. Rotate the pipe to allow
removal of heat exchanger.
12. Disconnect the condensate pipe from the condensate trap spigot.
Important
Disconnecting the condensate system may ease trap removal.
13. Ease the rear condensate trap from the heat exchanger and re­
move.
14. Whilst supporting the heat exchanger, disengage the clip from the
front. Ease the heat exchanger down and away from the boiler.
15. Reassemble in reverse order.
Warning
Care must be taken with the heat exchanger support/spring clip
when reassembling. Ensure the guides on the rear of the heat ex­
changer engage fully with the 2 retaining tags on the boiler chas­
sis.
7672024 - 1 - 03112016
59
10 Maintenance
10.4
Hydraulics maintenance
10.4.1
Expansion vessel
Warning
Take precautions to protect other components from water damage
when removing the expansion vessel.
Fig.57
Removing the expansion vessel
1. Close the flow and return isolation taps and drain the primary circuit.
2. Relieve the pressure from the expansion vessel.
3. Prise off the securing clips and disconnect the braided hose from the
vessel and hydraulic inlet assembly, taking care as water may still
be in the vessel.
4. Ensure that the braided hose is free of restriction, as a boiler with a
blocked hose will exhibit symptoms similar to one with a failed ves­
sel.
Important
Where the hose is found to be blocked it must be cleared or re­
placed and the vessel re-charged to 1 bar.
5. If the hose is clear support the vessel, undo the locknut and ma­
noeuvre the vessel out of the boiler.
6. Reassemble in reverse order and recharge to 1 bar.
PN-0000239
10.4.2
Fig.58
Removing the pump
Pump - complete
Warning
Take precautions to protect other components from water damage
when removing the pump and auto air vent.
1. Hinge the control box down.
2. Close the flow and return isolation taps and drain the boiler primary
circuit. Disconnect the electrical plugs from the pump motor.
3. Undo the screws securing the body to the pipe and manifold and
draw the pump forward to remove.
4. Examine the "O" ring seals on the return pipe and manifold, replac­
ing if necessary.
5. Reassemble in reverse order.
PN-0000238
60
7672024 - 1 - 03112016
10 Maintenance
10.4.3
Auto air vent
Warning
Take precautions to protect other components from water damage
when removing the air vent.
Fig.59
Removing the auto air vent
1. Close the flow and return isolation taps and drain the boiler primary
circuit.
2. Unscrew the automatic air vent anti-clockwise and lift away from the
pump body.
3. Fit the new air vent and O-ring seal.
4. Reassemble in reverse order.
PN-0000282
10.4.4
Fig.60
Removing the plate heat exchanger
Plate heat exchanger
Important
It is recommended to isolate the cold water mains stop cock to the
dwelling.
1.
2.
3.
4.
Close the flow and return isolation taps and the cold mains inlet.
Drain the primary circuit and draw off any residual DHW.
Hinge the control box downwards.
Remove the air/gas unit.
See
Air/gas unit, page 57, paragraph 1 to 6 to remove.
PN-0000240
7672024 - 1 - 03112016
5. Undo the screws securing the plate heat exchanger to the hydraulic
assembly.
6. Withdraw the plate heat exchanger by manoeuvring it to the rear of
the boiler, then upwards and to the left to remove.
Seals
7. There are four rubber seals between the hydraulic assembly and
heat exchanger which may need replacement.
8. Ease the seals out of the hydraulic assembly. Replace carefully, en­
suring that the each seal is inserted parallel and pushed fully in.
9. Reassemble in reverse order.
61
10 Maintenance
10.4.5
Fig.61
Removing the hydraulic pressure
sensor
1.
2.
3.
4.
Hydraulic pressure sensor
Close the flow and return isolation taps.
Drain the primary circuit.
Hinge the control box down.
Remove the air/gas unit.
See
Air/gas unit, page 57, paragraph 1 to 6 to remove.
5. Pull the two spade connections off the hydraulic pressure sensor.
6. Draw the securing clip forwards to release the sensor and remove.
7. Fit new sensor and reassemble in reverse order.
PN-0000241
10.4.6
Fig.62
Removing the DHW flow sensor
(Hall effect sensor)
DHW flow sensor (hall effect sensor)
1. Hinge the control box down.
2. Remove the air/gas unit.
See
Air/gas unit, page 57, paragraph 1 to 6 to remove.
3. Pull the sensor off the DHW inlet manifold.
4. Disconnect the plug from the sensor and connect it to the new com­
ponent.
5. Fit the new sensor, ensuring it is correctly oriented and fully engag­
ed over the manifold.
PN-0000242
10.4.7
Fig.63
Removing the DHW flow regulator
and filter
DHW flow regulator and filter
Important
It is recommended to isolate the cold water mains stop cock to the
dwelling.
1.
2.
3.
4.
Close the cold mains inlet.
Drain off any residual DHW.
Hinge the control box down.
Remove the air/gas unit.
See
Air/gas unit, page 57, paragraph 1 to 6 to remove.
5. Pull out the securing clip and prise the regulator and filter assembly
out of the hydraulic inlet assembly.
6. Twist the body to unlock the bayonet connection on the filter and re­
move the regulator.
7. Examine and clean the filter or replace.
8. Fit the new regulator and reassemble in reverse order.
PN-0000248
62
7672024 - 1 - 03112016
10 Maintenance
10.4.8
Fig.64
Removing the diverter valve motor
Diverter valve motor
1. Hinge the control box down.
2. Remove the air/gas unit.
See
Air/gas unit, page 57, paragraph 1 to 6 to remove.
PN-0000243
3. Undo the screw securing the electrical plug to the motor unit. Dis­
connect the plug.
4. Hold the motor in place against the spring pressure of the valve and
removing the securing clip.
5. Remove the motor.
6. When fitting the new motor it will be necessary to hold the unit firmly
while depressing the valve return spring.
7. Reassemble in reverse order.
10.4.9
Fig.65
Removing the diverter cartridge
1.
2.
3.
4.
5.
Diverter valve cartridge
Close the flow and return isolation taps.
Drain the primary circuit.
Hinge the HMI control box down.
Remove the air/gas unit.
Remove the diverter valve motor.
See
Diverter valve motor, page 63
6. Remove the pressure gauge clip and ease the pressure gauge away
from its housing.
PN-0000281
Important
It is recommended to completely remove the pressure gauge to
ease the access to the diverter cartridge. Push the plastic retain­
ing spring clips away and press the gauge out.
7. Remove the clip securing the central heating filter.
8. Grip the central heating filter firmly and pull away. Note the orienta­
tion of the o-ring seal.
9. Remove the diverter valve cartridge clip.
10. Grip the cartridge firmly and pull away from the o-ring seal.
11. Reassemble in reverse order.
10.4.10 Pressure relief valve
Fig.66
Removing the pressure relief valve
Important
It may be necessary to dismantle the PRV pipework.
1. Remove the pipe from the pressure relief valve outlet by gripping
firmly and pulling down.
2. Reassemble in reverse order.
PN-0000280
7672024 - 1 - 03112016
63
11 Troubleshooting
11 Troubleshooting
11.1
Error codes
Error messages are displayed according to the type of fault.
Temporary fault
A temporary fault is indicated by an ‘H’ followed by a two-digit code num­
ber (e.g. .02). This code flashes and alternates with a second two-digit
code (e.g. .06) that indicates the specific fault.
A temporary fault prevents the boiler operating but will automatically reset
once the cause of the fault has been resolved.
See
Fault finding — temporary faults, page 64 for a list of temporary
faults and their possible solutions.
Permanent fault
A permanent fault ‘Lock out’ is indicated by an ‘E’ followed by a two-digit
code number (e.g. .02). This code flashes and alternates with a second
two-digit code (e.g. .07) which indicates the specific fault.
A permanent fault prevents the boiler operating and will not automatically
reset. Once the fault condition has been rectified the RESET button must
be pressed for 3 seconds to restart the boiler.
Warning
Pressing the RESET button for 5 seconds will start the de-aeration
process! The boiler will run in de-aeration for approximately 5 mi­
nutes before restarting.
See
Fault finding - permanent faults, page 65 for a list of permanent
faults and their possible solutions.
11.2
Tab.28
Fault finding — temporary faults
Temporary fault finding guide
Group
code
Specific
code
Description
Probable cause
Check/Reason
H:01
.00
Communication error between
gas valve and PCB
Fault in air/gas unit
Loose connection to gas valve
Replace air gas unit
Check gas valve connection
from PCB
H:01
.05
Maximum difference between
the flow and return temperature
exceeded
Non-existent or insufficient circu­ Check circulation/pump
lation
Check water pressure
Sensor error
Check sensors are operating
correctly
Check that the sensor has been
correctly fitted
Check the cleanliness of the
heat exchanger
H:01
.08
CH Flow temperature increasing Non-existent or insufficient circu­ Check circulation
too fast
lation
Check water pressure
Sensor error
Check sensors are operating
correctly
Check that the sensor has been
correctly fitted
Check the cleanliness of the
heat exchanger
H:01
.14
Maximum flow temperature ex­
ceeded
64
Non-existent or insufficient circu­ Check circulation.
lation
7672024 - 1 - 03112016
11 Troubleshooting
Group
code
Specific
code
Description
Probable cause
H:01
.18
No circulation of water
Non-existent or insufficient circu­ Check circulation
lation
Check water pressure
Sensor error
Check sensors are operating
correctly
Check that the sensor has been
correctly fitted
Check the cleanliness of the
heat exchanger
Check pump
H:01
.21
DHW flow temperature increas­
ing too fast
Non-existent or insufficient circu­ Check circulation
lation
Check water pressure
Sensor error
Check sensors are operating
correctly
Check that the sensor has been
correctly fitted
Check the cleanliness of the
heat exchanger
H:02
.02
No input of parameters C1/C2
PCB not configured
Input C1/C2
H:02
.03
Incorrect configuration settings
C1/C2
Incorrect C1/C2
Reset C1/C2
H:02
.04
Parameter error
Incorrect parameters
Reset C1/C2
H:02
.06
Low system water pressure
Water leak on boiler
Water leak on system
Check boiler
Check system
Repressurise system
H:03
.00
Communication error with NTC
flue sensor
Sensor not, or badly connected
Bad connection
Sensor fault
Check wiring
Check sensors are operating
correctly
Check that the sensor has been
correctly fitted
Replace the sensor if necessary
H:03
.01
Communication error with the
HMI PCB
HMI not connected
Check wiring
H:03
.02
No flame during operation
No ionization current
Purge gas supply to remove air
Check gas valve is fully opened
Check supply pressure
Check operation and setting of
the gas valve unit
Check air inlet and flue gas dis­
charge flues are not blocked
Check that there is no recircula­
tion of flue gases
11.3
Tab.29
Check/Reason
Fault finding - permanent faults
Permanent fault finding guide
Group
code
Specific
code
Description
Probable cause
Check/Reason
E:00
.04
Return temperature sensor
open-circuit
Sensor not or badly connected
Bad connection
Sensor fault
Check the wiring
Check that the sensors are oper­
ating correctly
Check that the sensor has been
correctly fitted
Replace the sensor if necessary
7672024 - 1 - 03112016
65
11 Troubleshooting
Group
code
Specific
code
Description
Probable cause
Check/Reason
E:00
.05
Return temperature sensor
short-circuit
Sensor not or badly connected
Bad connection
Sensor fault
Check the wiring
Check that the sensors are oper­
ating correctly
Check that the sensor has been
correctly fitted
Replace the sensor if necessary
E:01
.02
Temperature measured by re­
turn sensor greater than flow
sensor
Bad connection
Sensor fault
Sensor not or badly connected
Water circulation direction re­
versed
Flow and return pipes reversed
Replace the sensor if necessary
Check the circulation (direction,
pump, valves)
Check that the sensors are oper­
ating correctly
Check that the sensor has been
correctly fitted
Check pipework configuration
E:01
.04
5 x flame loss in 24 hours with
burner on
No ionization current
Purge the gas supply to remove
air
Check that the gas valve is fully
opened
Check the supply pressure
Check the operation and setting
of the gas valve unit
Check that the air inlet and flue
gas discharge flues are not
blocked
Check that there is no recircula­
tion of flue gases
E:01
.11
Incorrect fan speed
External draught over the boiler
Defective gas/air unit
Check for adequate draw on the
chimney connection
Check the gas/air unit and re­
place if necessary
E:01
.17
No circulation
No circulation
Sensor not or badly connected
Sensor fault
Vent the air in the heating sys­
tem
Check the water pressure
Check the wiring
Check the circulation (direction,
pump, valves)
Check the cleanliness of the
heat exchanger
Check that the sensors are oper­
ating correctly
Check that the sensor has been
correctly fitted
Replace the sensor if necessary
E:01
.20
Maximum flue gas temperature
reached (> 140 Deg C)
No circulation
Sensor fault
Vent the air in the heating sys­
tem
Check the water pressure
Check the wiring
Check the circulation (direction,
pump, valves)
Check the cleanliness of the
heat exchanger
Check that the sensors are oper­
ating correctly
Check that the sensor has been
correctly fitted
Replace the sensor if necessary
E:02
.00
Boiler reset in progress
Reset button pushed
Boiler carrying out reset (Infor­
mation only)
66
7672024 - 1 - 03112016
11 Troubleshooting
Group
code
Specific
code
Description
Probable cause
Check/Reason
E:02
.07
Low system water pressure
Water leak on boiler
Water leak on system
Check boiler
Check system
Repressurise system
E:02
.16
On board CSU time-out
Check PCB for damage
Replace the PCB if necessary
E:02
.17
Permanent loss of communica­
tion between gas valve and boil­
er PCB
Fault in air/gas unit
Loose connection to gas valve
Replace air/gas unit
Check gas valve connection
from PCB
E:02
.19
Jumper 1 changed
Check position of jumper 1
Put jumper 1 to the off position
E:02
.20
Jumper 2 changed
Check position of jumper 2
Put jumper 2 to the off position
E:02
.21
Jumper 3 changed
Check position of jumper 3
Put jumper 3 to the off position
E:02
.47
Connection to external device
unsuccessful
Check wiring to external device
Check wiring
E:02
.48
Configuration to external device
unsuccessful
Check pairing to external
Pair the devices
E:04
.00
Gas Valve fault
Gas valve not detected
Check the wiring
Check resistance across gas
valve terminals
Replace gas valve if necessary
E:04
.01
Flow temperature sensor shortcircuited
Sensor not or badly connected
Bad connection
Sensor fault
Check the wiring
Check that the sensors are oper­
ating correctly
Check that the sensor has been
correctly fitted
Replace the sensor if necessary
E:04
.02
Flow temperature sensor opencircuited
Sensor not or badly connected
Bad connection
Sensor fault
Check the wiring
Check that the sensors are oper­
ating correctly
Check that the sensor has been
correctly fitted
Replace the sensor if necessary
E:04
.03
Critical flow temperature
reached
Non-existent or insufficient circu­ Check circulation
lation
E:04
.04
Flue temperature sensor shortcircuited
Sensor not or badly connected
Bad connection
Sensor fault
Check the wiring
Check the sensors are operating
correctly
Check the sensor has been cor­
rectly fitted
Replace the sensor if necessary
E:04
.05
Flue temperature sensor opencircuited
Sensor not or badly connected
Bad connection
Sensor fault
Check the wiring
Check the sensors are operating
correctly
Check the sensor has been cor­
rectly fitted
Replace the sensor if necessary
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67
11 Troubleshooting
Group
code
Specific
code
Description
Probable cause
Check/Reason
E:04
.06
Critical flue gas temperature
reached
No circulation
Sensor fault
Vent the air in the heating sys­
tem
Check the water pressure
Check the wiring
Check the circulation (direction,
pump, valves)
Check the cleanliness of the
heat exchanger
Check that the sensors are oper­
ating correctly
Check that the sensor has been
correctly fitted
Replace the sensor if necessary
E:04
.08
Maximum safe temperature
reached (Safety thermostat
open-circuited)
No circulation
Sensor not or badly connected
Bad connection
Sensor fault
Vent the air in the heating sys­
tem
Check the water pressure
Check the wiring
Check the circulation (direction,
pump, valves)
Check the cleanliness of the
heat exchanger
Check that the sensors are oper­
ating correctly
Check that the sensor has been
correctly fitted
Replace the sensor if necessary
E:04
.10
5 burner start-up failures
No ignition
Check cabling of ignition trans­
former
Replace the ionization/ignition
electrode
Check the breakdown to earth
Check the condition of the burn­
er set
Check the earthing
Defective gas/air unit
Ignition arc but no flame forma­
tion
Check that the gas valve is fully
opened
Check the supply pressure
Purge the gas supply to remove
air
Check the operation and setting
of the gas valve unit
Check that the air inlet and flue
gas discharge flues are not
blocked
Check the wiring on the gas
valve
Defective gas/air unit
Presence of flame but insuffi­
cient ionization (<1μA)
Check that the gas valve is fully
opened
Check the supply pressure
Replace the ionization/ignition
electrode
Check the earthing
Check the wiring on the ioniza­
tion/ignition electrode
68
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11 Troubleshooting
Group
code
Specific
code
Description
Probable cause
Check/Reason
E:04
.12
False flame signal
Short-term fluctuation of the
mains
Ionization current present even
though there is no flame
The burner remains very hot
(CO2 too high)
Defective gas/air unit
Press the RESET button for 5
seconds
Replace the ionization/ignition
electrode
Set the CO2
Check the gas/air unit and re­
place if necessary
E:04
.13
Fan rotor blocked
Fan seized
Wiring to fan damaged
Replace air/gas unit
E:04
.17
Problem on the gas valve
Defective gas/air unit
Replace gas/air unit
11.4
Fig.67
Accessing the information menu
Press the
1. The key is used to access the various menus and to scroll up and
down the information in the Information menu.
key
MW-3000237-2
Fig.68
Accessing the information menu
2. To access the Information menu, briefly press the
key once.
Caution
A long press (approximately 3 seconds) of the button will acti­
vate functions intended only for your installer or service engineer.
If this occurs, press the button again for 3 seconds to exit the
function.
PN-0000290
11.5
Important
Five minutes after the key is pressed for the last time, the dis­
play goes back to the main display, once the venting cycle has
been completed.
Reading out operating parameters
Pressing the
er is working.
button enables you to view information about how the boil­
1. Press this button for one second to view the operating mode (e.g. "t.
17" = purging in progress).
2. Press this button for one second again to view the operating substatus or the corresponding function that is active (e.g. "u.00" = boil­
er in standby mode).
3. Press this button for one second again to view the operating temper­
symbol followed by the temper­
ature in the heating system: The
ature in °C will flash.
4. Press this button for one second again to view the operating temper­
ature in the domestic water system: The
symbol followed by the
temperature in °C will flash.
5. Press this button for one second again to view the power level from
0 to 100: The
symbol and the number relating to the level of op­
erating power will flash.
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69
11 Troubleshooting
Press and hold the
menu.
11.6
button for more than three seconds to exit this
Statuses and sub-statuses
The STATUS is the instantaneous operating phase of the boiler at the
moment of display.
The SUB-STATUS is the instantaneous operating phase of the boiler
within the STATUS at the moment of display.
Tab.30
List of statuses
STATUS
DISPLAY
Standby
t00
Heat request
t01
Burner on
t02
Operating in heating mode
t03
Operating in domestic water mode
t04
Burner off
t05
Pump post circulation
t06
Burner off to reach the temperature setpoint
t08
Temporary fault
t09
Permanent fault (fault to be reset manually)
t10
Chimney sweep function at minimum output
t11
Chimney sweep function at maximum output in heating mode
t12
Chimney sweep function at maximum output in domestic water mode
t13
Manual heat request
t15
Frost protection function active
t16
Venting function active
t17
Electronic board overheated (wait for it to cool)
t18
Boiler in reset phase
t19
Tab.31
List of sub-statuses
SUB-STATUS
DISPLAY
Standby
U00
Wait time until next ignition in heating mode
U01
Pre-ventilation
U13
Burner pre-ignition
U17
Burner ignition
U18
Flame check
U19
Fan operation with active request
U20
Operation at set temperature setpoint
U30
Operation at limited temperature setpoint
U31
Operation at maximum output available
U32
Level 1 gradient detected
U33
Level 2 gradient detected
U34
70
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11 Troubleshooting
SUB-STATUS
DISPLAY
Level 3 gradient detected
U35
Flame protection active
U36
Stabilisation time
U37
Boiler start at minimum output
U38
Post ventilation
U41
Fan off
U44
Output reduction due to high flue gas temperature
U45
Pump post circulation
U60
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71
12 Decommissioning
12 Decommissioning
12.1
Decommissioning procedure
Disconnect the gas & electric supplies and isolate them.
Drain the primary circuit and disconnect the filling device.
Dismantle the chimney system and remove the boiler from the wall mount­
ing frame.
72
7672024 - 1 - 03112016
13 Spare parts
13 Spare parts
13.1
Short parts list
The following spares are available:
Fig.69
Tab.32
Spare parts
Key No.
63
135
242
528
Part number and description of spare parts
Description
Part Number
135
Safety thermostat
7661894
63
Detection/Spark ignition electrode
7661804
528
Flow sensor and Return sensor
7662085
242
NTC flue sensor
7662034
624
Hall effect sensor
7662101
154
Air/Gas unit 24kW
Air/Gas unit 28kW
7661938
7661952
347
HMI control
7662052
408
Burner assembly
7662070
29
Insulation rear
7661741
30
Insulation front
7661745
72
Pump assembly
7220533
340
Hydraulic pressure sensor
7662048
337
Diverter valve motor
7662047
120
3–way valve cartridge
7661857
76
Plate heat exchanger 24kW
Plate heat exchanger 28kW
7661816
7661819
35
Expansion vessel
7661749
409
Auto air vent
720777601
154
624
408
347
29
30
409
72
340
120
337
35
76
PN-0000245
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73
14 Appendix
14 Appendix
14.1
Combustion check on small heating systems
1. Use the procedure shown below to carry out the combustion check.
Fig.70
Small system combustion check
Combustion Check
Start Chimney Sweep
mode - see section 7.4.2
Yes
Can
the appliance be
operated on central
heating for 10 mins
without reaching
maximum temp. ?
Turn DHW knob to MAX
& open DHW taps to
create demand
No
Press button 5 times
until load value displayed
Open more DHW taps to
increase to maximum
load
No
Is load
reading 100 ?
(Fig. 1)
Yes
Fig. 1
Is load
reading 100 ?
(Fig. 1)
Yes
Measure & record
combustion
• If incorrect at
commissioning call Baxi
Customer Support
0344 871 1545
• If incorrect when
changing gas valve
adjust & re-check as
described in section
10.3.7
Start Chimney Sweep mode - see
section 7.4.2 and set to minimum load.
If changing gas valve adjust & re-check
as described in section 10.3.7
Close all DHW taps
Measure & record combustion
• If incorrect at commissioning call Baxi Customer Support 0344 871 1545
• If incorrect when changing gas valve adjust & re-check
Stop chimney sweep mode by pressing
button for 3 seconds
PN-0000300
74
7672024 - 1 - 03112016
14 Appendix
14.2
Benchmark commissioning checklist
This Commissioning Checklist is to be completed in full by the competent person who commissioned the boiler as a means of demonstrating
compliance with the appropriate Building Regulations and then handed to the customer to keep for future reference.
Failure to install and commission according to the manufacturer’s instructions and complete this Benchmark Commissioning Checklist will invalidate the
warranty. This does not affect the customer’s statutory rights.
Customer name:
Telephone number:
Address:
Boiler make and model:
Boiler serial number:
Commissioned by (PRINT NAME):
Gas Safe register number:
Company name:
Telephone number:
Company address:
Commissioning date:
CONTROLS (tick the appropriate boxes)
Time and temperature control to heating
Time and temperature control to hot water
Room thermostat and programmer/timer
Programmable room thermostat
Load/weather compensation
Optimum start control
Cylinder thermostat and programmer/timer
Combination Boiler
Heating zone valves
Fitted
Not required
Hot water zone valves
Fitted
Not required
Thermostatic radiator valves
Fitted
Not required
Automatic bypass to system
Fitted
Not required
Boiler interlock
Provided
ALL SYSTEMS
’s instructions
Yes
What system cleaner was used?
What inhibitor was used?
Quantity
Yes
litres
No
CENTRAL HEATING MODE measure and record:
Gas rate
m³/hr
OR
ft³/hr
Burner operating pressure (if applicable)
mbar
OR Gas inlet pressure
mbar
°C
Central heating return temperature
°C
COMBINATION BOILERS ONLY
Is the installation in a hard water area (above 200ppm)?
Yes
No
Yes
No
DOMESTIC HOT WATER MODE Measure and Record:
OR
Gas rate
m³/hr
Burner operating pressure (at maximum rate)
mbar OR Gas inlet pressure at maximum rate
ft³/hr
mbar
Cold water inlet temperature
Hot water has been checked at all outlets
°C
Yes
Temperature
°C
I/min
CONDENSING BOILERS ONLY
The condensate drain has been installed in accordance with the manufacturer’s instructions and/or BS5546/BS6798
7672024 - 1 - 03112016
Yes
75
14 Appendix
ALL INSTALLATIONS
Record the following:
At max. rate:
CO
ppm AND
At min. rate: (where possible)
CO
ppm AND
CO/CO²
CO/CO²
Ratio
Ratio
The heating and hot water system complies with the appropriate Building Regulations
Yes
The boiler and associated products have been installed and commissioned in accordance with the manufacturer’s instructions
Yes
The operation of the boiler and system controls have been demonstrated to and understood by the customer
Yes
The manufacturer’s literature, including Benchmark Checklist and Service Record, has been explained and left with the customer
Yes
Commissioning Engineer’s Signature
Customer’s Signature
*All installations in England and Wales must be
to Local Authority Building Control (LABC) either directly or through a
Competent Persons Scheme. A Building Regulations Compliance
will then be issued to the customer.
© Heating and Hotwater Industry Council (HHIC)
14.3
www.centralheating.co.uk
Service records
It is recommended that your heating system is serviced regularly and that the appropriate Service Interval Record is completed.
Service Provider
Before completing the appropriate Service Record below, please ensure you have carried out the service as described in the manufacturer’s instructions.
SERVICE 01
Date:
SERVICE 02
Engineer name:
Engineer name:
Company name:
Company name:
Telephone No:
Telephone No:
Gas safe register No:
Record:
Gas safe register No:
CO
ppm
AND
At min. rate: (Where Possible) CO
ppm
AND
At max. rate:
CO² %
CO² %
Record:
CO
ppm
AND
At min. rate: (Where Possible) CO
ppm
AND
At max. rate:
Comments:
Comments:
Signature
Signature
SERVICE 03
Date:
SERVICE 04
Engineer name:
Engineer name:
Company name:
Company name:
Telephone No:
Telephone No:
Gas safe register No:
Record:
ppm
AND
At min. rate: (Where Possible) CO
ppm
AND
CO² %
CO² %
Record:
CO
ppm
AND
ppm
AND
Comments:
Signature
Signature
SERVICE 05
Date:
SERVICE 06
Engineer name:
Engineer name:
Company name:
Company name:
Telephone No:
Telephone No:
Gas safe register No:
Record:
CO² %
CO² %
Date:
Gas safe register No:
CO
ppm
AND
At min. rate: (Where Possible) CO
ppm
AND
CO² %
CO² %
Record:
CO
ppm
AND
At min. rate: (Where Possible) CO
ppm
AND
At max. rate:
Comments:
Comments:
Signature
Signature
76
Date:
At min. rate: (Where Possible) CO
At max. rate:
Comments:
At max. rate:
CO² %
CO² %
Gas safe register No:
CO
At max. rate:
Date:
CO² %
CO² %
7672024 - 1 - 03112016
14 Appendix
SERVICE 07
Date:
SERVICE 08
Engineer name:
Engineer name:
Company name:
Company name:
Telephone No:
Telephone No:
Gas safe register No:
Record:
Gas safe register No:
CO
ppm
AND
At min. rate: (Where Possible) CO
ppm
AND
At max. rate:
CO² %
CO² %
Record:
CO
ppm
AND
At min. rate: (Where Possible) CO
ppm
AND
At max. rate:
Comments:
Comments:
Signature
Signature
SERVICE 09
Date:
SERVICE 10
Engineer name:
Engineer name:
Company name:
Company name:
Telephone No:
Telephone No:
Gas safe register No:
Record:
CO² %
CO² %
Date:
Gas safe register No:
CO
ppm
AND
At min. rate: (Where Possible) CO
ppm
AND
At max. rate:
Date:
CO² %
CO² %
Record:
CO
ppm
AND
At min. rate: (Where Possible) CO
ppm
AND
At max. rate:
Comments:
Comments:
Signature
Signature
CO² %
CO² %
to Local Authority Building Control (LABC) either directly or through a
*All installations in England and Wales must be
Competent Persons Scheme. A Building Regulations Compliance
will then be issued to the customer.
© Heating and Hotwater Industry Council (HHIC)
7672024 - 1 - 03112016
www.centralheating.co.uk
77
14 Appendix
78
7672024 - 1 - 03112016
© Copyright
All technical and technological information contained in these technical instructions, as well as any drawings and technical de­
scriptions supplied, remain our property and shall not be multiplied without our prior consent in writing. Subject to alterations.
Baxi Customer Support
0344 871 1545
Opening hours
Monday - Friday, 8.00am-6.00pm
Weekends and Bank Holidays, 8.30am-2.00pm
Please note calls may be recorded for training and monitoring purposes
baxi.co.uk
Register now to activate your warranty:
www.baxi.co.uk/registration
For the warranty to be maintained, please make sure...
1
2
3
Benchmark checklist is completed
Warranty is registered within 30 days
The boiler has an annual service
For full terms and conditions, visit www.baxi.co.uk/terms. Failure to adhere to
terms and conditions will void your manufacturer’s warranty.
Baxi
Brooks House,
Coventry Road,
Warwick, CV34 4LL
Please ensure the boiler is installed in accordance with these installation
instructions and that you adhere to the Building Regulations.
e&oe
All descriptions and illustrations provided in this document have been
carefully prepared but we reserve the right to make changes and
improvements in our products which may affect the accuracy of the
information contained in this leaflet. All goods are sold subject to our
standard Conditions of Sale which are available on request.
7672024 - 1 - 03112016