United Kingdom
en
Installation and Service Manual
Condensing Combination Boiler
124 - 128
Combi
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.
Model Range
Building Regulations and the Benchmark Commissioning
Checklist
Baxi 124 Combi
G.C.No 47-077-25
Baxi 128 Combi
G.C.No 47-077-26
Warning !
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.
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 reference.
Installers are required to carry out installation, commissioning and servicing 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 information.
© Baxi Heating UK Ltd 2016 All rights reserved. No part of this publication may
be reproduced or transmitted in any form or by any means, or stored in any
retrieval system of any nature (including in any database), in each case whether
electronic, mechanical, recording or otherwise, without the prior written
permission of the copyright owner, except for permitted fair dealing under
Copyrights, Designs and Patents Act 1988.
Applications for the copyright owner’s permission to reproduce or make other
use of any part of this publication should be made, giving details of the proposed
use, to the following address:
Building Regulations (England & Wales) require notification of
the installation of a heating appliance to the relevant Local
Authority Building Control Department. This can be achieved
via a Competent Persons Self Certification Scheme as an
option to notifying the Local Authority directly.
The Health & Safety Executive operates the ‘Gas Safe Register’,
a self-certification scheme for gas heating appliances.
These arrangements represent a change from the situation
whereby compliance with Building Regulations was accepted as
being demonstrated by completion of the Benchmark Logbook
(which was then left on site with the customer).
With the introduction of Self Certification Schemes, the
Benchmark Logbook is being withdrawn. However, a similar
document in the form of a commissioning checklist and service
interval record is incorporated at the back of these instructions.
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 installation and commissioning of central heating
systems in the UK and to encourage the regular servicing of all
central heating systems to ensure safety and efficiency.
Building Regulations require that installations should comply
with manufacturer'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 necessary to ensure compliance with Building
Regulations.
The Company Secretary, Baxi Heating UK Limited,
Brooks House, Coventry Road, Warwick. CV34 4LL
Full acknowledgement of author and source must be given.
WARNING: Any person who does any unauthorised act in relation to a
copyright work may be liable to criminal prosecution and civil claims for damages.
0086
ISO 9001
FM 00866
2
© Baxi Heating UK Ltd 2016
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
© Baxi Heating UK Ltd 2016
LABC will record the data
and will issue a
certificate of compliance
3
Legislation
IMPORTANT - Installation, Commissioning, Service & Repair
This appliance must be installed in accordance with the manufacturer’s instructions and
the regulations in force. Read the instructions fully before installing or using the
appliance.
In GB, this must be carried out by a competent person as stated in the Gas Safety
(Installation & Use) Regulations.
Definition of competence: A person who works for a Gas Safe registered company
and holding current certificates in the relevant ACS modules, is deemed competent.
In IE, this must be carried out by a competent person as stated in I.S. 813 “Domestic
Gas Installations”.
The addition of anything that may interfere with the normal operation of the appliance
without express written permission from the manufacturer or his agent could invalidate
the appliance warranty. In GB this could also infringe the Gas Safety (Installation and
Use) Regulations.
Warning - Check the information on the data plate is compatible with local supply
conditions.
All Gas Safe registered engineers carry an ID card with their licence number and a
photograph. You can check your engineer is registered by telephoning
0800 408 5500 or online at www.gassaferegister.co.uk
This company declare that no substances harmful to health
are contained in the appliance or used during appliance
manufacture.
The appliance is suitable only for installation in GB and IE and
should be installed in accordance with the rules in force, and
only used in a suitably ventilated location.
In GB, the installation must be carried out by a Gas Safe
Registered Installer. It must be carried out in accordance with
the relevant requirements of the:
• Gas Safety (Installation & Use) Regulations.
• The appropriate Building Regulations either The Building
Regulations, The Building Regulations (Scotland), Building
Regulations (Northern Ireland).
• The Water Fittings Regulations or Water Byelaws in
Scotland.
• The Current I.E.E. Wiring Regulations.
Where no specific instructions are given, reference should be
made to the relevant British Standard Code of Practice.
In IE, the installation must be carried out by a competent
Person and installed in accordance with the current edition of
I.S. 813 ‘Domestic Gas Installations’, the current Building
Regulations and reference should be made to the current ETCI
rules for electrical installation.
All systems must be thoroughly flushed and treated with
inhibitor (see section 6.2).
Homologations
CE Marking
EC - Declaration of Conformity
Baxi Heating UK Limited being the manufacturer / distributor within the European
Economic Area of the following
Baxi Combi 124 - 128
declare that the above is in conformity with the provisions of the Council Directive
2009/142/EC, 92/42/EEC, 2009/125/EC,
2010/30/EC, 2014/35/EU, 2014/30/EU
and has been subject to the following conformity procedures laid down in
Annex 2 - Article 3 of 2009/142/EC
under the supervision of the British Standards Institution, a Notified Body authorized
by the United Kingdom Competent Authority, and carrying the Notified Body
Number 0086.
Type test for purpose of Regulation 5 certified by:
Notified Body 0085.
Product/Production certified by:
Notified Body 0086.
For GB/IE only.
4
© Baxi Heating UK Ltd 2016
Codes of Practice - refer to the most recent version
In GB the following Codes of Practice apply:
Standard
Scope
BS 6891
Gas Installation.
BS 5482 Part 1
Butane & Propane Gas Installation
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 systems.
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 water systems.
BS 7593
Treatment of water in domestic hot water
central heating systems.
In IE the following Codes of Practice apply:
Standard
Scope
I.S. 813
Domestic Gas Installations.
The following standards give valuable additional information;
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 systems.
BS 7074
Expansion vessels and ancillary equipment for
sealed water systems.
BS 7593
Treatment of water in domestic hot water
central heating systems.
Safe Manual 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 shoulders, arms and hands.
Health & Safety is the responsibility of EVERYONE.
There is no ‘safe’ limit for one man - each person has different capabilities. 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 unobstructed. 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 possible.
Where possible transport the boiler using a sack truck or other suitable trolley.
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 recommended lift points.
Remember
The circumstances of each installation are different. Always asses the risks associated with handling and lifting according to the individual conditions.
If at any time when installing the boiler you feel that you may have injured yourself STOP !!
DO NOT ‘work through’ the pain - you may cause further injury.
IF IN ANY DOUBT DO NOT HANDLE OR LIFT THE BOILER - OBTAIN ADVICE OR ASSISTANCE BEFORE PROCEEDING !!
© Baxi Heating UK Ltd 2016
5
CONTENTS
Section
6
© Baxi Heating UK Ltd 2016
Page
1.0
Introduction
7
2.0
General Layout
8
3.0
Appliance Operation
9
4.0
Technical Data
10
5.0
Dimensions and Fixings
12
6.0
System Details
13
7.0
Site Requirements
16
8.0
Flue Options
21
9.0
Installation
23
10.0
Commissioning
28
11.0
Completion & System Draining
31
12.0
Servicing
32
13.0
Changing Components
34
14.0
Combustion & Calibration
43
15.0
Electrical
44
16.0
Short Parts List
45
17.0
Fault Finding & ‘Service Due’
46
18.0
Optional Outdoor Sensors
52
Benchmark Checklist
58
1.0 Introduction
1.1
Description
1. The Baxi Combi 100 Range are fully automatic gas fired wall
mounted condensing combination boilers. They are room sealed
and fan assisted, and will serve central heating and mains fed
domestic hot water.
2. The boiler is set to give a maximum output of :24 models - 24 kW DHW
21.2 kW CH Pnc (Condensing)
28 models - 28 kW DHW
25.3 kW CH Pnc (Condensing)
Information Label
3. The boiler is factory set for use on Natural Gas (G20). It can
be adapted to operate on Propane (G31) - see Section 10.1
‘Gas Type Check’.
4. The boiler is suitable for use only on fully pumped sealed
heating systems. Priority is given to domestic hot water.
5. The boiler data badge gives details of the model, serial
number and Gas Council number and is situated on the control
box. It is visible when the case front panel is removed (Fig. 2).
Control Flap
6. The boiler model, serial number and Gas Council number are
also shown on the information label behind the boiler control
flap (Fig. 1). This is for user reference.
Fig. 1
7. The boiler is intended to be installed in residential/domestic
environments on a governed meter supply only.
8. The boiler must be installed with one of the purpose
designed flues such as one of the standard horizontal telescopic
flue kits detailed in the Flue Installation Guide.
9. All systems must be thoroughly cleansed, flushed and
treated with inhibitor (see section 6.2).
1.2
Optional Extras
Various timers, external controls, etc. are available as optional
extras. Full details are contained in the relevant sales literature.
1.3
Contents of Pack
The pack contains:• Boiler
• Valve & Copper Tail Set
• Template
• Fittings & Literature Pack
Gas Type Label
Data Badge
Fig. 2
© Baxi Heating UK Ltd 2016
NOTE: These Installation & Servicing Instructions MUST be
read in conjunction with the Flue Installation Guide supplied
in the Literature Pack.
7
2.0 General Layout
2.1
2
Layout
8
3
1
12
11
1.
Expansion Vessel
2.
Boiler Adaptor
3.
Primary Heat Exchanger
4.
DHW Plate Heat Exchanger
5.
Pump with Automatic Air Vent
6.
Central Heating System Pressure Gauge
7.
Fan Assembly
8.
Exp. Vessel Locating Stud
9.
Flame Sensing Electrode
10.
Air/Gas Collector
11.
Spark Ignition Electrode
12.
Combustion Box Cover & Burner
13.
Control Box Display
14.
Condensate Trap
15.
Safety Pressure Relief Valve
16.
Gas Valve
17.
Diverter Valve Motor
18.
Boiler Control
19.
Optional Timer
20.
Boiler Drain Tap
21.
Heating Flow Sensor
22.
Safety Thermostat
10
9
7
13
15
17
4
19
18
21
22
6
5
16
14
20
8
© Baxi Heating UK Ltd 2016
Boiler Schematic
Layout
19
3.0 Appliance Operation
3.1
20
18
1. With a demand for heating, the pump circulates water
through the primary circuit.
21
2. Once the burner ignites the fan speed controls the gas
rate to maintain the heating temperature measured by the
temperature sensor.
22
3. When the flow temperature exceeds the setting
temperature, a 3 minute delay occurs before the burner
relights automatically (anti-cycling). The pump continues to
run during this period.
23
24
4. When the demand is satisfied the burner is extinguished
and the pump continues to run for a period of 3 minutes
(Pump Overrun).
25
26
28
3.2
27
17
Domestic Hot Water Mode
1. Priority is given to the domestic hot water supply. A
demand at a tap or shower will override any central heating
requirement.
16
2. The flow of water will operate the Domestic Hot Water
Sensor (‘Hall Effect Sensor’) which requests the 3 way valve
to change position. This will allow the pump to circulate the
primary water through the DHW plate heat exchanger.
15
13
3. The burner will light automatically and the temperature of
the domestic hot water is controlled by the temperature
sensor.
1
2
14
M
7
8
12
6
10
11
A
Central Heating Mode
B
4
5
9
C
D
E
F
Fig. 3
Key
1. Pump with Automatic Air Vent
2. Diverter Valve Assembly
3. Diverter Valve motor
4. CH System Pressure Gauge
5. Central Heating Filter
6. Domestic Hot Water Filter
7. Domestic Hot Water Priority Sensor
(‘Hall Effect Sensor’)
8. Domestic Hot Water NTC sensor
9. Non-return Valve
10. Hydraulic Pressure Sensor
11. Boiler Drain Tap
12. Pressure Relief Valve
13. Plate Heat Exchanger
14. Condensate Trap
15. Gas Valve
16. Safety Thermostat (105°C)
17. Heating Flow Sensor
18. Flue Sensor
19. Boiler Adaptor
20. Primary Heat Exchanger
21. Spark Ignition Electrode
22. Burner
23. Flame Sensing Electrode
24. Air/Gas Collector
25. Return Heating Sensor
26. Fan
27. Air/Gas Venturi
28. Expansion Vessel
Connections:A – Condensate Drain
B – Heating Flow
C – Domestic Hot Water Outlet
D – Gas Inlet
E – Cold Water Inlet On/Off Valve and filter
F – Heating Return
© Baxi Heating UK Ltd 2016
3
4. When the domestic hot water demand ceases the burner
will extinguish and the diverter valve will remain in the
domestic hot water mode, unless there is a demand for
central heating.
3.3
Boiler Frost Protection Mode
1. The frost protection mode is integral to the appliance and
functions as long as there is power to the boiler, as indicated
by the standby signal
.
2. With CH & DHW or CH only selected, when the boiler
temperature falls below 5°C the boiler will fire until a
temperature of 30°C is reached.
3. If DHW only is selected, when the boiler CH temperature
falls below 5°C the boiler will fire until a temperature of
30°C is reached. When the boiler DHW temperature falls
below 5°C the boiler will fire until a temperature of 7°C is
reached.
4. Further protection can be incorporated by using a system
frost thermostat.
3.4
Pump Protection
1. If the boiler has been inactive for a period of 24 hours the
pump will automatically operate for 1 minute to prevent
sticking.
9
4.0 Technical Data
4.1
NOx Class
Electrical Protection
C13 C33
Appliance Type
124 & 128 Combi
IPX5D
Appliance Category
Min
3.89
4.32
Heat Output CH Pn (Non-Condensing)
Max
Min
24 model
kW
20
3.4
28 model
kW
24
3.8
Heat Output CH Pnc (Condensing)
Max
24 model
kW
21.2
28 model
kW
25.3
Min
3.7
4.1
Heat Input DHW Qnw Hs (Gross)
Max
24 model
kW
27.4
28 model
kW
32.1
Heat Output DHW
24 model
kW
28 model
kW
Injector
24 model
28 model
mm
mm
Max
24
28
4.4
4.6
NATURAL GAS ONLY !
Max Gas Rate
24 model
28 model
(Natural Gas - G20)
(After 10 mins)
m3/h
2.61
m3/h
3.05
Inlet Pressure (Natural Gas - G20)
mbar
20
PROPANE ONLY !
Max Gas Rate
24 model
28 model
(Propane - G31)
(After 10 mins)
kg/h
1.96
kg/h
2.29
Inlet Pressure (Propane - G31)
mbar
37
External Fuse Rating
3A
Internal Fuse Rating
F2L
Central Heating Primary Circuit
Pressures
Condensate Drain
To accept 21.5mm (3/4 in) plastic waste pipe
Flue Terminal
Dimensions
Diameter
Projection
Connections
Gas Inlet
Heating Flow
Heating Return
Cold Water Inlet
Hot Water Outlet
Pressure Relief Discharge
-
100mm
125mm
DHW Circuit
Pressures
Max Operating
Min Operating
copper tails
22mm
22mm
22mm
15mm
15mm
15mm
bar
8
0.15
Flow Rates
(24) (28)
l/min l/min
DHW Flow Rate
@ 30o C Rise
10.9
12.9
DHW Flow Rate
@ 35o C Rise
9.8
11.5
Min Working
DHW Flow Rate
2
2
IMPORTANT: Where Low Flow Taps or Fittings are
intended to be used in the DHW system connected it is
strongly recommended that the DHW flow rate DOES
NOT fall below 2.5l/min. This will ensure reliable
operation of the DHW function.
175mm Min
170mm Min*
450mm Min (For Servicing)
5mm Min (In Operation)
5mm Min
5mm Min :
Expansion Vessel
- (For Central Heating only.
Integral with appliance)
bar
Min Pre-charge Pressure
1
*This is MINIMUM recommended dimension. Greater
clearance will aid installation and maintenance.
Weights
Packaged Boiler Carton
Installation Lift Weight
bar
3
2.5
0.5
1-2
Safety Discharge
Max Operating
Min Operating
Recommended Operating Range
Outercase Dimensions
Casing Height
- 700mm
Overall Height Inc Flue Elbow
- 860mm
Casing Width
- 390mm
Casing Depth
- 300mm*
*This can be reduced to 290mm by removing the
boiler control access flap
Clearances
Above Casing
Below Casing
Front
Front
L.H. Side
R.H. Side
N.G. 9.0% ± 0.7
L.P.G. 10.5% ± 1.0
CO2
CAT II 2H 3P
Heat Input CH Qn Hs (Gross)
Max
24 model
kW
20.22
28 model
kW
26.64
5
36.5kg
32.5 kg
SEDBUK Declaration
SAP 2009 Annual Efficiency for N. G.
models is 89%
Max Capacity of
CH System
litre
100
Primary Water Content
of Boiler (unpressurised)
2.5
Temperatures
C.H. Flow Temp (adjustable)
25°C to 80°C max (± 5°C)
This value is used in the UK Government’s Standard
Assessment Procedure (SAP) for energy rating of
D.H.W. Flow Temp (adjustable)
35°C to 60°C max (± 5°C)
dependent upon flow rate
dwellings. The test data from which it has been calculated
has been certified by 0035.
Pump
Available Head
Electrical Supply
230V~ 50Hz
(Appliance must be connected to an
earthed supply)
See graph below
Pump - Available Head
6
Power Consumption
24 model
W
28 model
W
5.5
85
90
5
4.5
4
3.5
Metre (wg)
3
2.5
2
1.5
NOTE: All data in this section are nominal values
and subject to normal production tolerances.
1
0.5
0
10
© Baxi Heating UK Ltd 2016
0
200
400
600
Flow Rate (l/h)
800
1000
1200
4.0 Technical Data
4.2
Technical Parameters
Technical parameters for boiler combination heaters
Baxi Combi
124
128
Condensing boiler
Yes
Yes
Low-temperature boiler(1)
No
No
B1 boiler
No
No
Cogeneration space heater
No
No
Combination heater
Yes
Yes
Prated
kW
20
24
Useful heat output at rated heat output
and high temperature regime(2)
P4
kW
20.0
24.0
Useful heat output at 30% of rated heat
output and low temperature regime(1)
P1
kW
6.7
8.0
Seasonal space heating energy efficiency Šs
%
93
93
Useful efficiency at rated heat output and Š4
high temperature regime(2)
%
88.0
87.9
Š1
%
98.0
98.0
Full load
elmax
kW
0.030
0.042
Part load
elmin
kW
0.013
0.013
Standby mode
PSB
kW
0.003
0.003
Standby heat loss
Pstby
kW
0.035
0.035
Ignition burner power consumption
Pign
kW
-
-
Annual energy consumption
QHE
kWh
GJ
17204
62
20645
74
Sound power level, indoors
LWA
dB
49
50
Emissions of nitrogen oxides
NOX
mg/kWh
15
17
XL
XL
Daily electricity consumption
Qelec
kWh
0.162
0.232
Annual electricity consumption
AEC
kWh
36
51
Water heating energy efficiency
Šwh
%
88
86
Daily fuel consumption
Qfuel
kWh
22
22
Annual fuel consumption
AFC
GJ
17
17
Rated heat output
Useful efficiency at 30% of rated heat
output and low temperature regime(1)
Auxiliary electricity consumption
Other items
Domestic hot water parameters
Declared load profile
(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.
© Baxi Heating UK Ltd 2016
11
5.0 Dimensions and Fixings
There must be no part of the air duct
(white tube) visible outside the property.
Dimensions
At least 1.5°
E
G
A 700mm
B 300mm*
*This can be reduced to 290mm by
removing the boiler control access flap
C 390mm
A
D 116mm Ø Min.
E 160mm
(207mm for 80/125mm
flue systems)
B
F 130mm
360° Orientation
G 106mm
H 228mm
H
D
J
C
162mm
J
Flue Ø 100mm
F
Boiler
Side
Boiler
Side
Hot Water
Outlet
(15mm)
Heating
Flow
(22mm)
Gas
Inlet
(22mm)
Cold Water
Inlet
(15mm)
Heating
Return
(22mm)
Pressure
Relief
Valve
(15mm)
Condensate
Drain
25
40 mm mm
65 mm
162,5 mm
12
© Baxi Heating UK Ltd 2016
65 mm
65 mm
65 mm
65 mm
6.0 System Details
6.1
Information
1. The Baxi 100 range of Condensing Combination Boilers are
‘Water Byelaws Scheme - Approved Products’.
To comply with the Water Byelaws your attention is drawn to
the following installation requirements and notes (IRN).
a) IRN 001 See text of entry for installation
requirements and notes.
b) IRN 302 Byelaw 14.
2. Reference to the WRc publications, ‘Water fittings and
materials directory’ and ‘Water supply byelaws guide’ give full
details of byelaws and the IRNs.
6.2
Treatment of Water Circulating Systems
1. All recirculatory water systems will be subject to corrosion
unless they are flushed and an appropriate water treatment is
applied. To prevent this, follow the guidelines given in BS
7593 “Treatment of Water in Domestic Hot Water Central
Heating Systems” and the treatment manufacturers
instructions.
2. Treatment must involve the use of a proprietary cleanser,
such as Sentinel X300 or X400, or Fernox F3 and an inhibitor
such as Sentinel X100 or Fernox MB-1.
3. Full instructions are supplied with the products, for further
information contact Sentinel (0800 389 4670) or Fernox
(0870 870 0362).
Failure to flush and add inhibitor to the system will
invalidate the appliance warranty.
4. It is important to check the inhibitor concentration after
installation, system modification and at every service in
accordance with the inhibitor manufacturer’s instructions.
(Test kits are available from inhibitor stockists.)
5. For information or advice regarding any of the above
contact Technical Enquiries 0344 871 1545.
6.3
Bypass
1. The boiler is fitted with an automatic integral bypass. Some
systems may require an additional external bypass.
6.4
System Control
1. 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
(2010). A range of optional controls are available. Full details
are contained in the relevant Sales Literature.
© Baxi Heating UK Ltd 2016
13
6.0 System Details
6.5
Stop
Valve
Double
Check
Valve
DHW
Mains
Inlet
1. 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.
Stop
Valve
Temporary
Loop
System Filling and Pressurising
CH
Return
2. A filling loop that connects to the primary return & cold
mains inlet valves is available as an accessory. Follow the
instructions provided with it.
3. The filling method adopted must be in accordance with all
relevant water supply regulations and use approved equipment.
Fig. 4
4. Your attention is drawn to:
for GB: Guidance G24.2 and recommendation R24.2 of the
Water Regulations Guide.
for IE: the current edition of I.S. 813 “Domestic Gas
Installations”.
Filling Loop
Connections
Fig. 5
5. 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 prevention device is
permanently connected at the inlet to the circuit and the
temporary connection is removed after use.
6.6
Expansion Vessel (Central Heating only)
1. The appliance expansion vessel is pre-charged to 1 bar.
Therefore, the minimum cold fill pressure is 1 bar. The vessel is
suitable for correct operation for system capacities up to 100
litres. For greater system capacities an additional expansion
vessel must be fitted. For GB refer to BS 7074 Pt 1. For IE, the
current edition of I.S. 813 “Domestic Gas Installations”.
6.7
Safety Pressure Relief Valve (Fig. 6)
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 excess of 100°C.
The end of the pipe should
2. The pressure relief discharge pipe should be not less than
15mm dia, run continuously downward, and discharge outside
the building, preferably 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 (Fig. 6a).
terminate facing down and
towards the wall
Fig. 6a
Control Box removed
for clarity
Fig. 6
3. The discharge must not be above a window, entrance or
other public access. Consideration must be given to the
possibility that boiling water/steam could discharge from the
pipe.
4. A remote relief valve kit is available to enable the boiler to be
installed in cellars or similar locations below outside ground
level (kit no. 5121379).
Pressure Relief Valve
Discharge Pipe
14
© Baxi Heating UK Ltd 2016
5. A boiler discharge pump is available, part no. 720648301.
This pump will dispose of both condensate & high temperature
water from the relief valve. It has a maximum head of 5 metres.
6.0 System Details
6.8
Domestic Hot Water Circuit (Fig. 7)
1. All DHW circuits, connections, fittings, etc. should be fully in
accordance with relevant standards and water supply regulations.
Other Tap
Outlets
Expansion
Vessel*
Boiler
Check
Valve*
Pressure Reducer
Valve*
To Hot
Taps
Stop Tap
*See 6.8 for instances when
these items may be required
Fig. 7
IMPORTANT: Where Low Flow Taps or
Fittings are intended to be used in the DHW
system connected to a Baxi 124/128 Combi it is
strongly recommended that the DHW flow rate
DOES NOT fall below 2.5l/min. This will ensure
reliable operation of the DHW function.
2. Your attention is drawn to:
for GB: Guidance G17 to G24 and recommendation R17 to R24
of the Water Regulations Guide.
for IE: the current edition of I.S. 813 “Domestic Gas Installations”.
3. 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 prevention device
as any thermal expansion is accommodated within the appliance.
It is possible in certain circumstances that other cold water
demands (e.g. washing machines, flushing of W.C.s) may affect
the DHW function of the boiler. In these instances the fitting of a
backflow prevention device and expansion vessel is
recommended.
4. In instances where the mains water supply incorporates a nonreturn backflow prevention device, or any other device that
includes one*, it is possible for a build-up of pressure to occur.
This may result 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
recommendations are not followed.
5. The boiler’s maximum working mains pressure is 8 bar,
therefore all pipework, 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.
6.9
Showers
1. If a shower control is supplied from the appliance it should be
of the thermostatic or pressure balanced type. Thermostatic type
shower valves provide the best comfort and guard against water
at too high a temperature. Existing controls may not be suitable refer to the shower valve manufacturer.
6.10
Hard Water Areas
1. Only water that has NOT been artificially softened must used
when filling or re-pressurising the primary system. If the mains
cold water to the property is fitted with an artificial
softening/treatment device the source use to fill or
re-pressurise the system must be upstream of such a device.
© Baxi Heating UK Ltd 2016
15
390mm
5mm Min
7.0 Site Requirements
5mm Min
7.1
175mm Min
(300mm Min if
using 80/125mm
flueing system)
Location
1. 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 permitting satisfactory removal of
combustion products and providing an adequate air supply.
The boiler should be fitted within the building unless
otherwise protected by a suitable enclosure i.e. garage or
outhouse. (The boiler may be fitted inside a cupboard-see
Section 7.3).
2. 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 permanent live is left on to give
BOILER frost protection. NOTE: THIS WILL NOT PROTECT
THE SYSTEM !
700mm
3. 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 I.E.E. Wiring Regulations and Building
Regulations.
In IE reference should be made to the current edition of I.S.
813 “Domestic Gas Installations” and the current ETCI rules.
4. 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 Engineers Publication IGE/UP/7
(Gas Installations in Timber Framed Housing).
Fig. 8
170mm* Min
7.2
Clearances (Figs. 8 & 9)
1. A flat vertical area is required for the installation of the
boiler.
At least 1.5°
2. 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.
*This is MINIMUM recommended dimension. Greater
clearance will aid installation and maintenance.
7.3
Ventilation of Compartments
450mm Min
1. Where the appliance is installed in a cupboard or
compartment, no air vents are required.
For Servicing
Purposes
2. BS 5440: Part 2 refers to room sealed appliances installed
in compartments. The appliance will run sufficiently cool
without ventilation.
5mm Min
In Operation
Fig. 9
16
© Baxi Heating UK Ltd 2016
300mm
(290mm with flap removed)
7.0 Site Requirement
7.4
Gas Supply
1. The gas installation should be in accordance with the
relevant standards. In GB this is BS 6891 (NG) or BS 5482
Pt. 1 (LPG). In IE this is the current edition of I.S. 813
“Domestic Gas Installations”.
2. The connection to the appliance is a 22mm copper tail
located at the rear of the gas service cock (Fig. 10).
3. 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 taken into
consideration. Do not use pipes of a smaller diameter than
the boiler 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.
Gas Service Cock
7.5
Electrical Supply
Fig. 10
1. External wiring must be correctly earthed, polarised and
in accordance with relevant regulations/rules. In GB this is
the current I.E.E. Wiring Regulations. In IE reference should
be made to the current edition of ETCI rules.
Zone 2
Window
Recess
2. The mains supply is 230V ~ 50Hz fused at 3A.
Zone 1
Zone 2
NOTE: The method of connection to the electricity
supply must facilitate complete electrical isolation of the
appliance.
Zone 0
0.6 m
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.
Window
Recess
Zone 2
7.6
Fig. A
In GB Only
Ceiling
Window Recess
Zone 2
Zone 1
Zone 2
Outside Zones
Bath & Shower Rooms
1. If the boiler is fitted in a room containing a bath or
shower it can be fitted in zone 2, (Figs. A & B shows zone
dimensions for a bathtub. For other examples refer to the
Current I.E.E. Wiring Regulations) reference must be made
to the relevant requirements.
In GB this is the current I.E.E. Wiring Regulations and
Building Regulations.
In IE reference should be made to the current edition of
I.S. 813 “Domestic Gas Installations” and the current ETCI
rules.
2.25 m
Zone 0
0.6 m
Fig. B
© Baxi Heating UK Ltd 2016
In GB Only
17
Examples are shown of the following methods of termination:i) to an internal soil & vent pipe
ii) via an internal discharge branch (e.g. sink waste) downstream of the trap
iii) to a drain or gully
iv) to a purpose made soakaway
v) pumped into an internal discharge branch (e.g. sink waste) downstream of the trap
vi) pumped into an external soil & vent pipe
vii) to a drain or gully with extended external run & trace heating
It is strongly recommended to discharge internally into the household
drainage system. If connecting to a rain water drain, that drain MUST
discharge into a foul drain.
Insulation
32mm
21.5mm
Boiler
i) Termination to an internal soil and
vent pipe
50mm
p
2.5° M er metre of p
inimum
ipe run
fall
450mm min*
*450mm is applicable to properties
up to 3 storeys.
For multi-storey building installations
consult BS 6798.
Boiler
50mm
Sink
ii) External termination via internal discharge branch
e.g sink waste - downstream*
per me
tre of
2.5° M
pipe ru
inimum
n
fall
Pipe must terminate above
water level but below
surrounding surface. Cut
end at 45°
*It is NOT RECOMMENDED
to connect upstream of the
sink or other waste water
receptacle !
7.0 Site Requirements
7.7
Condensate Drain
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 PIPEWORK BEING SUBJECT TO
FREEZING CONDITIONS AND APPROPRIATE
MEASURES TAKEN TO PREVENT BLOCKAGE.
CORRECT INSTALLATION IN ACCORDANCE WITH
THIS SECTION WILL CONSIDERABLY MINIMISE THE
LIKELIHOOD OF BLOCKAGE AND SUBSEQUENT
BOILER LOCK-OUT.
A CONDENSATE DISCHARGE PUMP AND PIPE ‘TRACE
HEATING’ ARE AVAILABLE AS ACCESSORIES - see
paragraphs 7.7.12 to 7.715 for further details.
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 suitable condensate pump in basement and
cellar or similar applications.
The boiler condensate trap incorporates a seal of 75mm,
therefore it is unnecessary to install an air break and trap in
the discharge pipework.
1. 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.
2. 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.
3. The discharge pipe should be run in a proprietary drain pipe
material e.g. PVC, PVC-U, ABS, PVC-C or PP.
4. Metal pipework is NOT suitable for use in condensate
discharge systems.
Boiler
5. The pipe should be a minimum of 21.5mm diameter and
must be supported using suitably spaced clips of the correct
design to prevent sagging.
iii) Termination to a drain or gully
50mm
p
of pipe er metre
run
2.5° M
inimum
fall
Pipe must terminate above
water level but below
surrounding surface. Cut
end at 45°
6. It is advisable that the full length of condensate pipe is run
internally and preferably be less than 3 metres.
7. Internal runs greater than 3 metres or runs in cold areas
should use 32mm waste pipe.
8. External runs MUST be a MINIMUM of 32mm and fully
insulated with material suitable for external use.
iv) Termination to a purpose made soakaway
Further specific requirements for soakaway
design are referred to in BS 6798.
Boiler
50mm p
er metr
e
of pipe
run
2.5° Min
imum fa
18
© Baxi Heating UK Ltd 2016
ll
500mm min
Holes in the soak-away must
face away from the building
9. If the boiler is fitted in an unheated location the entire
condensate discharge pipe should be treated as an external run
and sized and insulated accordingly.
10. In all cases discharge pipe must be installed to aid disposal of
the condensate. 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.
11. 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 subjected to internal pressure fluctuations
when WC's are flushed or sinks emptied then back-pressure
may force water out of the boiler trap and cause appliance
lockout.
v) pumped into an internal discharge branch
(e.g. sink waste) downstream of the trap
Sink
50mm
7.0 Site Requirements
per me
tre of p
ipe run
2.5° M
inimum
fall
Pipe must terminate above
water level but below
surrounding surface. Cut
end at 45°
7.7
Condensate Drain (cont.)
12. A boiler discharge pump is available, ‘MULTIFIT’
part no. 720648301. This pump 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.
13. Condensate Drain Pipe ‘Trace Heating’ Elements are
available in various lengths. ‘MULTIFIT’ part nos.:-
Basement or similar
(heated)
1 metre 720644401
2 metre 720664101
3 metre 720664201
5 metre 720664401*
Boiler
*Where the drain is between 3 & 5 metres a 5 metre kit can
be used and “doubled back” upon itself.
14. It is possible to fit the element externally on the
condensate drain or internally as detailed in the instructions
provided.
Condensate Pump
15. The fitting of a ‘Trace Heating’ Element is NOT a
substitute for correct installation of the condensate drain.
ALL requirements in this section must still be adhered to.
vi) pumped into an external soil & vent pipe
50mm
Unheated Location
(e.g. Garage)
per me
tre of p
ipe run
2.5° M
inimum
fall
Basement or similar
(heated)
vii) to a drain or gully with extended
external run & trace heating
Boiler
The ‘Trace Heating’ element
must be installed in accordance
with the instructions supplied.
External runs & those in
unheated locations still require
insulation.
Boiler
Condensate Pump
50mm
per me
tre of
2.5° M
inimum
© Baxi Heating UK Ltd 2016
pipe ru
n
fall
Pipe must terminate above
water level but below
surrounding surface. Cut
end at 45°
19
Terminal Position with Minimum Distance (Fig. 12)
(mm)
A1 Directly below an opening, air brick, opening
windows, etc.
B1 Above an opening, air brick, opening window etc.
C1 Horizontally to an opening, air brick, opening window etc.
D2 Below gutters, soil pipes or drain pipes.
E2 Below eaves.
F2 Below balconies or car port roof.
G2 From a vertical drain pipe or soil pipe.
H2 From an internal or external corner.
I
Above ground, roof or balcony level.
J
From a surface or boundary line facing a terminal.
K From a terminal facing a terminal (Horizontal flue).
From a terminal facing a terminal (Vertical flue).
L From an opening in carport (e.g. door, window)
into the dwelling.
M Vertically from a terminal on the same wall.
N Horizontally from a terminal on the same wall.
R From adjacent wall to flue (vertical only).
S From an adjacent opening window (vertical only).
T Adjacent to windows or openings on pitched and flat roofs
U Below windows or openings on pitched roofs
7.0 Site Requirements
300
300
300
25 (75)
25 (200)
25 (200)
25 (150)
25 (300)
300
600
1200
600
7.8
NOTE: Due to the nature of the boiler a plume of water
vapour will be discharged from the flue. This should be
taken into account when siting the flue terminal.
1. The following guidelines indicate the general requirements
for siting balanced 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 “Domestic Gas
Installations”.
1200
1500
300
300
1000
600
2000
2. If the terminal discharges onto a pathway or passageway,
check that combustion products will not cause a nuisance
and that the terminal will not obstruct the passageway.
1 In addition, the terminal should be no nearer than 150 mm to an opening in the
3. 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.
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 dimensions
IMPORTANT:
• Under car ports we recommend the use of the plume
displacement kit.
• The terminal position must ensure the safe and
nuisance - free dispersal of combustion products.
D, E, F, G or H is 25mm then the remainder MUST be as shown in brackets, in
accordance with B.S.5440-1.
NOTE: The distance from a fanned draught appliance terminal
installed parallel to a boundary may not be less than 300mm in
accordance with the diagram below
300 min
Terminal
Assembly
Flue
*4. Reduction to the boundary is possible down to 25mm by
using the available flue deflector.
*
Plume
Displacement Kit
IMPORTANT: If fitting a Plume
Displacement Flue Kit, the air inlet
must be a minimum of 150mm from
any opening windows or doors (see
Fig. 13).
Top View Rear Flue
Fig. 11
Property Boundary Line
T
Air Inlet
J,K
U
Opening Window
or Door
150mm
MIN.
N
R
I
M
C
I
I
F
D
E
A
S
I
F
J,K
B
L
A
A
G
H
H
I
Likely flue positions requiring
a flue terminal guard
20
© Baxi Heating UK Ltd 2016
Fig. 12
Fig. 13
8.0 Flue Options
8.1
Horizontal Flue Systems
1. The standard flue is suitable only for horizontal
termination applications.
(ii)
(i)
2. All fittings should be fully engaged. The approximate
engagement is 40mm. Apply the lubricant supplied to the
seal on each fitting to aid assembly.
3. Maximum permissible equivalent flue lengths are:(60/100)
(80/125)
Horizontal Concentric 10 metres
20 metres
4. Any additional “in line” bends in the flue system must be
taken into consideration.
Their equivalent lengths are:Concentric Pipes:
135° bend
0.5 metres
93° bend
1.0 metres
5. The elbow supplied with the standard horizontal
telescopic flue kit is not included in any equivalent length
calculations.
Plume Displacement Kit 60 /100 dia
1M Extensions 45° & 93° elbows
are also available - see the separate
Flue Guide.
NOTE: Flue length is measured from point (i) to (ii) as
shown.
Horizontal
Flues
IMPORTANT
SUPPORT - All flue systems MUST be securely
supported a MINIMUM of once every metre. 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.
NOTE: Horizontal flue pipes should always be installed with a fall of at least 1.5°
from the terminal to allow condensate to run back to the boiler.
6. Read this section in conjunction with the Flue Installation
Guide supplied with the boiler.
This bend is equivalent to
1 metre
C
A
(ii)
B
(i)
This bend is equivalent to
1 metre
Total equivalent length =
A+B+C+2 x 90° Bends
© Baxi Heating UK Ltd 2016
21
8.0 Flue Options
8.2
m
0m
50
The standard horizontal telescopic flue kit allows for lengths
between 315mm and 500mm from elbow to terminal without
the need for cutting (Fig. 14).
Extensions of 250mm, 500mm & 1m are available.
m
5m
31
Flue Lengths
The maximum permissible equivalent flue length is:
10 metres (60/100 system - vertical & horizontal)
20 metres (80/125 system - vertical & horizontal)
8 metres (60/100 system - vertical connected to
ridge terminal)
Fig. 14
For details of Plume Displacement Kit lengths see the Flue
Installation Guide supplied in the literature pack.
8.3
Flue Trim
1. The flexible flue trims supplied can be fitted on the outer and
inner faces of the wall of installation.
Flue Deflector
8.4
Ensure that no part of the
white outer chimney duct
is visible
Terminal Guard (Fig. 15)
1. When codes of practice dictate the use of terminal guards,
‘Multifit’ accessory part no. 720627901 can be used (Note: This
is not compatible with Flue Deflector referred to below).
Fig. 16
2. If a proprietary guard is used it must be identified as suitable
for use with condensing boilers
3. There must be a clearance of at least 50mm between any
part of the terminal and the guard.
4. The flue terminal guard should be positioned centrally over
the terminal and fixed as illustrated.
8.5
Fig. 15
Flue Deflector (Fig. 16)
1. 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.
8.6
Flue Accessories
1. For full details of Flue Accessories (elbows, extensions, clamps
etc.) refer to the Flue Installation Guide supplied in the literature
pack.
22
© Baxi Heating UK Ltd 2016
9.0 Installation
9.1
IMPORTANT
RISK ASSESSMENT - Before commencing the installation
it is recommended that the ‘Five Steps to Risk
Assessment’ document published by the HSE is consulted,
and an assessment performed as described.
GAS SUPPLY - The gas supply, gas type and pressure
must be checked for suitability before connection (see
Section 7.4).
SNAP OFF
Fig. 17
Part No. 7659616
116mm Dia Minimum
Aperture For Flue Tube
130mm
Side Flue
Centre Line
175 mm
Minimum
Clearance
Vertical Flue
Centre Line
228 mm
1. Remove the banding and the cardboard sleeve. Remove the
polystyrene top piece and installation kit (Fig. 17).
Boiler Wall Mounting Plate
Fixing Slots
Ø 8 mm
Unpacking & Initial Preparation
50 mm
2. After considering the site requirements (see Section 7.0)
position the fixing template (Fig. 19) on the wall ensuring it is
level both horizontally and vertically.
For Side Flue Exit
Fig. 18
Profile of
Outercase
3. Mark the position of the two most suitable fixing slots for
the wall plate.
5 mm Minimum
Side Clearance
4. Mark the position of the centre of the flue hole (rear exit).
For side flue exit, mark as shown (Fig. 18).
5 mm Minimum
Side Clearance
5. If required, mark the position of the gas and water pipes.
Remove the template.
Fig. 19a
6. Cut the hole for the flue (minimum diameter 116mm).
Condensate
Drain
Pressure
Relief
Valve
(15mm)
7. Drill the wall as previously marked to accept the wall plugs
supplied. Secure the wall plate using the fixing screws.
200mm
Recommended
170mm
Minimum
Clearance
26.5
38.5mm mm
65mm
65mm
65mm
65mm
65mm
162.5 mm (PRV)
Heating
Flow
(22mm)
Part No. 7659616-01 (4/16)
Hot Water
Outlet
(15mm)
Combi Only
Not System
Gas
Inlet
(22mm)
Cold Water
Inlet
(15mm)
8. Using a spirit level ensure that the plate is level (Fig. 19a)
before finally tightening the screws.
Heating
Return
(22mm)
Combi Only
Not System
Fig. 19
9.2
Flushing
1. Ensure that the system is thoroughly flushed and treated in
accordance with guidance given in Section 6.2 & BS 7593.
9.3
Fitting The Boiler
1. Remove the sealing caps from the boiler connections.
NOTE: A small amount of water may drain from the boiler
once the caps are removed.
2. Lift the boiler using the lower polystyrene. The boiler should
be lifted by TWO PEOPLE. Engage the mounting bracket at
the top rear of the boiler on the wall plate (Fig. 20) (see Safe
Manual Handling page 5).
LIFT HERE
BOTH SIDES
Sealing Washers
Fig. 20
3. Identify the valves prior to fitting to the boiler (Fig. 21).
4. Insert the sealing washers between the valves, boiler
connections and copper tails.
Remove Sealing Caps from
under the Boiler before lifting
into position
5. Tighten all the connections.
Heating
Flow
DHW
Outlet
Fig. 21
© Baxi Heating UK Ltd 2016
Gas
Cold Water
Inlet
Heating
Return
23
9.0 Installation
9.4
Prime Trap by pouring
300ml of water into
flue spigot
Fitting the Pressure Relief Discharge Pipe
(Fig. 22)
1. Remove the discharge pipe from the kit.
2. Determine the routing of the discharge pipe in the vicinity
of the boiler. 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. The relief valve is intentionally
angled to the right of the boiler. DO NOT adjust the
position of the valve. The discharge pipe must be installed
before pressurising the system.
Fig. 22a
Pressure Relief Valve
3. The pipework must be at least 15mm diameter and run
continuously downwards to a discharge point outside the
building. See section 6.7 for further details.
4. Utilising one of the sealing washers, connect the discharge
pipe to the adaptor and tighten the nut hand tight, plus 1/4
turn to seal.
5. Complete the discharge pipework and route it to the
outside discharge point.
Fig. 22
Discharge Pipe
Control Box removed
for clarity
9.5
Condensate Drain (see section 7.7) (Fig. 23)
1. Using the elbow supplied, connect the condensate drain
pipework to the boiler condensate trap outlet pipe. When
connecting the elbow, ensure that the condensate sump is
not inadvertently unscrewed.
Ensure the discharge of condensate complies with any
national or local regulations in force (see British Gas
“Guidance Notes for the Installation of Domestic Gas
Condensing Boilers” & HHIC recommendations).
Condensate Trap
Outlet Pipe
Fig. 23
2. The hose will accept 21.5mm (3/4in) plastic overflow pipe
which should generally discharge internally into the
household drainage system. If this is not possible, discharge
into an outside drain is acceptable.
3. The boiler condensate trap should be primed by pouring
approximately 300ml of water into the flue spigot (Fig. 22a).
Do not allow any water to fall into the air inlet.
24
© Baxi Heating UK Ltd 2016
9.0 Installation
m
0m
50
m
5m
31
9.6
Fitting The Flue
HORIZONTAL TELESCOPIC FLUE
Terminal Assembly
1. There are two telescopic sections, the Terminal
Assembly and the Connection Assembly, a roll of sealing
tape and two self tapping screws. A 93° elbow is also
supplied.
Fig. 24
2. The two sections can be adjusted to provide a length
between 315mm and 500mm (Fig. 24) when measured
from the flue elbow (there is 40mm engagement into the
elbow).
Connection Assembly
Wall Thickness
3. Locate the flue elbow on the adaptor at the top of the
boiler. Set the elbow to the required orientation (Fig. 25).
NOTE: The flue elbow is angled at 93 degrees to
ensure a fall back to the boiler.
(X)
4. Measure the distance from the outside wall face to the
elbow. This dimension will be known as ‘X’ (Fig. 25).
5. If the distance from the flue elbow to the outside face of
the wall (‘X’ in Fig. 25) is less than 250mm the Connection
Assembly can be discarded and the Terminal Assembly
fitted directly into the elbow.
(X)
Wall
Thickness
Fig. 25
6. In instances where the dimension ‘X’ (Fig. 25) is between
250mm and 315mm it will be necessary to shorten the
Terminal Assembly by careful cutting to accommodate
walls of these thicknesses.
7. To dimension ‘X’ add 40mm. This dimension to be
known as ‘Y’.
‘Peak’ to be uppermost
8. Adjust the two telescopic sections to dimension ‘Y’ and
seal the joint with the tape provided (Fig. 27). Ensure that
the labels marked ‘TOP’ on the Terminal and Connection
Assemblies are uppermost.
9. Using the clearance holes in the Connection Assembly
secure it to the Terminal Assembly using the screws
supplied (Fig. 28).
Fig. 26
‘TOP’ Label
’
n ‘Y
io
ens
Dim
Securing Screw
Sealing Tape
Fig. 27
Fig. 28
‘TOP’ Label
© Baxi Heating UK Ltd 2016
25
9.0 Installation
Boiler Elbow
Apply the lubricant
supplied for ease of
assembly (do not use
any other type).
9.6
Fitting the Flue (Cont)
10. 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 (Fig. 29).
Adaptor
Ensure Elbow is fully
engaged into Boiler
Adaptor
11. 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 (Fig. 30).
Fig. 29
12. Ensure that the terminal is positioned with the slots to
the bottom (Fig. 31). Secure the flue to the elbow with the
screws supplied (Fig. 30).
Apply the lubricant
supplied for ease of
assembly (do not use
any other type).
IMPORTANT: It is essential that the flue terminal is fitted
as shown to ensure correct boiler operation and prevent
water entering the flue.
Ensure Flue is fully
engaged into Elbow
13. Make good between the wall and air duct outside the
building, appropriate to the wall construction and fire rating.
14. If necessary fit a terminal guard (see Section 8.4).
Fig. 30
Slots at bottom
Fig. 31
26
© Baxi Heating UK Ltd 2016
9.0 Installation
9.7
Making The Electrical Connections
1. See Section 7.5 for details of the electrical supply. Undo
the securing screws and lift the case front panel off.
2. Disengage the securing tab and hinge the control box
downwards. Undo the terminal block cover securing screw
and remove the cover (Fig. 34).
3. Slacken the gland nut in the left of the boiler lower panel
and pass the mains cable through it. Remove the grommet
adjacent to the gland nut, pierce the diaphragm and insert
the cable from the external control system.
Control Box
4. Leave sufficient slack in the cables to allow the Control
Box to be hinged fully open. Tighten the gland nut and refit
the grommet.
5. Connect the Earth, Permanent Live and Neutral wires to
the terminal strip.
Fig. 34
6. Refer to the instructions supplied with the external
control(s).
Fused Spur
L
NOTE: Both the Permanent Live and Neutral
connections are fused.
N
IMPORTANT: Any thermostat MUST be suitable for
230V switching.
Room ‘Stat
N
Fig. 35
b
7. Remove the link between terminals 1 & 2. The 230V
supply at terminal 2 must be connected to the thermostat.
The switched output from the thermostat must be
connected to terminal 1. (Figs. 35 & 36). If the room
thermostat being used incorporates an anticipator it MUST
be wired as shown in Figs. 35 & 36.
1
bk 2
230V
g/y
b
N
NOTE: When only Low Voltage controls are being used
(connected to Terminal M2) it is necessary to remove
the link wire !
br
L
8. Replace the terminal block cover.
Frost Thermostat
Pipe Thermostat
Fused Spur
L
9. See Section 18.0 for details of fitting the Optional Sensor
Accessories.
N
Room ‘Stat
230V
N
9.8
b
Fig. 36
230V
Preliminary Electrical Checks
1
bk 2
1. Prior to commissioning the boiler preliminary electrical
system checks should be carried out.
g/y
External Clock
N
L
b
2. These should be performed using a suitable meter, and
include checks for Earth Continuity, Resistance to Earth,
Short Circuit and Polarity.
br
NOTE: The 230V switched signal for external controls
(Frost Stat - Room Stat - Timer) must always be taken
from terminal 2 at the boiler. Live, Neutral and Earth to
power these controls must be taken from the Fused Spur.
© Baxi Heating UK Ltd 2016
27
11.0 Commissioning
10.0
10.1
Cap
Commissioning the Boiler
1. Reference should be made to BS:EN 12828, 12831 & 14336
when commissioning the boiler. Ensure that the trap has been
primed - see Section 9.5 paragraph 3.
Automatic Air
Vent
2. At the time of commissioning, complete all relevant sections of
the Benchmark Checklist at the rear of this publication.
3. Open the mains water supply to the boiler and all hot water
taps to purge the DHW system.
Fig. 37
4. 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 (Fig. 37).
Pump
2
1
3
4
0
bar
Control Box
removed for clarity
Heating
Pressure Gauge
Fig. 38
5. The system must be flushed in accordance with BS 7593 (see
Section 6.2) and the flushing agent manufacturers instructions.
6. Pressurise the system to 1.5 bar (Fig. 38) then close and
disconnect the filling loop.
7. 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".
De-Aeration Function
8. When power is supplied to the boiler for the first time the
software pressure will be displayed. followed by
. However
if
is shown, press
will now
R for 2 to 4 seconds .
be displayed.
9. Press
&
together and hold for at least 6 seconds.
The ‘De-Aeration’ Function will be activated and ‘On’ displayed.
Display showing Gas
Type Recognition
Fig. 39
IMPORTANT: The combustion for this appliance has been
checked, adjusted and preset at the factory for operation
on the gas type specified on the appliance data plate.
Do not adjust the air/gas ratio valve.
During the Gas Type Check Function the combustion
ratio will increase for a short time while the gas type is
established.
FUNCTION INTERRUPTION
If either De-aeration or Gas Check is interrupted by a fault
e.g. low water pressure (E118) or air in the gas supply
(E128 or E133) the fault must be rectified and the function
reactivated. During De-aeration, if water pressure is lost,
repressurising to 1.0 bar will allow the function to
continue. Whilst the Gas Type Check is being performed if
water pressure is lost the function can be reactivated by
repressurising then pressing
&
together and
holding for at least 6 seconds. If a gas supply fault occurs
&
.
R must be pressed before
28
© Baxi Heating UK Ltd 2016
10. The boiler pump will run for up to 10 minutes during which
time the diverter valve will switch between heating & hot water.
This will purge air from the system. The display will show
.
Gas Type Check
11. Once de-aeration is complete the boiler will go automatically
to first fire-up and run at the Ignition Phase fan speed for 3 or 4
minutes to check the gas type (N.G. or Propane L.P.G.). The boiler
software checks the combustion value against the set value.
will be displayed, alternating with a figure representing the
Ignition Phase speed, e.g. ‘33’ or ‘43’ (Note: Each boiler model
will display a different figure).
12. The boiler is factory set for Natural Gas. On a Natural Gas
Supply
will be displayed and the boiler is ready for the Inlet
Pressure & Gas Rate to be checked (Section 10.2).
13. IMPORTANT: In cases where the supplied gas is Propane
gas
will be displayed. Press
for at least 6 seconds to
confirm that this is the intended gas type for the installation.
14. IF THE BOILER IS TO BE OPERATED ON PROPANE A
SUITABLE PERMANENT MARKER PEN MUST BE USED TO
ALTER THE ‘GAS SETTING INFORMATION’ LABEL ADJACENT
TO THE DATA LABEL !
15. Having checked:
• 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.
Proceed to put the boiler into operation as follows:
Set Boiler to Maximum Rate
(see 10.3.1)
Allow the combustion to
stabilise. Do not insert probe to
avoid ‘flooding’ the analyser.
10.0 Commissioning
10.2
Checking the Combustion - ‘Chimney Sweep’
Function (cont)
1. Follow the flow chart opposite.
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% ?
No
TURN APPLIANCE OFF !
Call 0344 871 1545 for
advice. The appliance MUST
NOT be commissioned until
all problems are identified and
resolved.
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% ?
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.
Yes
Yes
No
Is CO < 350ppm
and CO/CO2 ratio
< 0.004 ?
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 ?
Yes
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
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.
© Baxi Heating UK Ltd 2016
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.
29
10.0 Commissioning
10.3
Check the Operational (Working) Gas Inlet
Pressure & Gas Rate
Note: The system MUST be cold to ensure the boiler is
operating under full demand. To obtain an accurate
measurement on smaller capacity systems it may be
necessary to open one or more hot taps in order to
maintain the boiler at full rate
1. Press
&
together and hold for at least 6
seconds. ‘On’ will be displayed briefly, followed by ‘304’
then ‘100’ when the boiler is lit, indicating the CH output is
at MAXIMUM (‘Chimney Sweep Function’).
DO NOT check
gas pressure here
2. With the boiler operating in the maximum rate condition
check that the operational (working) gas pressure at the inlet
gas pressure test point on the gas cock or valve is in
accordance with B.S. 6798 & B.S. 6891. This must be AT
LEAST 17mb ! (LPG - 37mb)
Fig. 41
Inlet Gas Pressure
Test Point
Fig. 40
3. Ensure that this inlet pressure can be obtained with all other
gas appliances in the property working.
Working Gas Pressures
If the pressure drops are
greater than shown a problem
with the pipework or
connections is indicated.
Permissible pressure drop
across this system 1 mbar.
Measure the Gas Rate
4. With any other appliances & pilot lights turned OFF the gas
rate can be measured. It should be:-
Gas Valve
18-22 mbar
19-23 mbar
Changing the Gas Type
1. It may be necessary to adjust the boiler gas type if the supply is changed, for example
when Natural Gas is provided to a rural area previously reliant on Propane. In these
instances a replacement Gas Type Label may be required, which is available on request
as a spare part.
and hold for at least 6 seconds.
5. Press
30
will be displayed,
. Press
5. Press
&
together and hold for at least 6
seconds to exit the function.
7. 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 Benchmark Commissioning Checklist.
Gas Type Label
.
to select the value that corresponds with the required
to save the change, then
© Baxi Heating UK Ltd 2016
24 model 1.94 kg/h
28 model 2.29 kg/h
N.G. Factory Set
to select the next parameter
4. Press
or
gas type. For Natural Gas:For Propane:-
Propane
6. Carefully read and complete all sections of the Benchmark
Commissioning 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. The publication
must be handed to the user for safe keeping and each
subsequent regular service visit recorded.
Gas Meter
3. Press
24 model 2.61 m3/h
28 model 3.05 m3/h
17-21 mbar
Gas Cock
2. Press
&
alternating with
.
Natural Gas
R to return to the normal display.
When reset for L.P.G.
11.0 Completion & System Draining
11.1
Completion
1. Replace the case front panel, and secure with the screws
previously removed.
2. This publication must be handed to the user for safe
keeping and each subsequent regular service visit recorded.
Case Front Panel
3. Set the central heating and hot water temperatures to
the requirements of the user. Instruct the user in the
operation of the boiler and system.
4. Instruct the user in the operation of the boiler controls.
Hand over the User Guide & Installation and Service
Manual, giving advice on the necessity of regular servicing.
5. 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.
Facia Panel
Fig. 42
6. Show the user the location of the system control isolation
switch, and demonstrate its operation.
7. 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.
To change the information
displayed see the table below:The
button can be pressed so that the display shows the following
information:1 press - ‘00’ alternates with Sub-Code (only when fault on boiler) or ‘000’
2 presses - ‘01’ alternates with CH Flow Temperature
3 presses - ‘02’ alternates with Outside Temperature (where Sensor fitted)
4 presses - ‘03’ alternates with DHW Temperature
5 presses - ‘04’ alternates with DHW Temperature
6 presses - ‘05’ alternates with System Water Pressure
7 presses - ‘06’ alternates with CH Return Temperature
8 presses - ‘07’ alternates with Flue Temperature
9 presses - ‘08’ alternates with Heat Exchanger Temperature
11.2
System Draining
1. If at any time after installation it is necessary to drain the
central heating system (e.g. after replacing a radiator) the
De-Aeration Function should be activated.
2. On refilling the system ensure that there is no heating or
hot water demand, but that there is power to the boiler.
3. Press
&
together and hold for at least 6
seconds. The ‘De-Aeration’ Function will be activated.
4. The boiler pump will run for up to 10 minutes during
which time the diverter valve will switch between heating &
hot water. This will purge air from the system. The display
will show
.
5. Once De-Aeration is complete set the external controls
as required by the user.
© Baxi Heating UK Ltd 2016
31
Flue Sampling
Point
12.0 Servicing
12.1
Performance Safety Check & Annual Servicing
1. 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 B.S. 7967-4.
Air Sampling
Point
2. 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
(check air inlet sample).
• The integrity of the boiler combustion circuit and relevant
seals as described in Section 12.2.
• The operational gas inlet pressure as described in Section
10.3.1 to 10.3.7 and the gas rate as described in 10.3.4.
• The combustion performance as described in ‘Check the
Combustion Performance’ (12.1.4 to 12.1.6 below).
3. Competence to carry out Checking Combustion
Performance
B.S. 6798 ‘Specification for Installation & Maintenance of Gas
Fired Boilers not exceeding 70kW’ advises that:-
Case Front Panel
Fig. 43
• 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.
Case Front Panel
Securing Screws
• The flue gas analyser used should be one meeting the
requirements of BS7927 or BS-EN50379-3 and be calibrated
in accordance with the analyser 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)
4. Set the boiler to operate at maximum rate as described in
Section 14.1.1 to 14.1.6.
5. 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.
Condensate Trap
Control Box removed
for clarity
6. If the combustion reading (CO/CO 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 ‘Annual Servicing - Inspection’ (Section 12.2) &
re-check.
• Perform the Combustion & Calibration functions (Section
14.0) & re-check.
• Replace the gas valve (Section 13.23) & re-check.
Gasket
12.2
Annual Servicing - Inspection
1. Ensure that the boiler is cool.
Sump
2. Ensure that both the gas and electrical supplies to the
boiler are isolated.
Fig. 44
Condensate
Drain Elbow
3. Remove the screws securing the case front panel. Lift the
panel slightly to disengage it from the studs on top of the case
(Fig. 43) and hinge down the Control Box.
4. Disconnect the condensate drain elbow and unscrew the
sump from the bottom of the condensate trap assembly (Fig.
44). Remove any deposits from the sump and trap. Clean as
necessary and replace the sump.
32
© Baxi Heating UK Ltd 2016
4 ±0.5
12.0 Servicing
12.2
Annual Servicing Inspection (Cont)
5. Remove the clip securing the gas feed pipe to the air/gas
venturi. Disconnect the pipe. Do not break the joint
between the pipe and gas valve unless necessary.
Flame
Sensing
Electrode
6. Disconnect the electrode leads, noting their position, and
the fan electrical plugs (Fig. 46).
5±
1
Spark Ignition
Electrode
7. Undo the four nuts retaining the combustion box cover
to the heat exchanger.
10 ±1
Fig. 45
Electrode Position
8. Carefully draw the fan, collector and cover assembly
forward (Figs. 46).
Fan, Collector and Cover
Assembly
9. Clean any debris from the heat exchanger and check that
the gaps between the tubes are clear.
Fig. 46
10. Inspect the burner, electrodes position and insulation,
cleaning or replacing if necessary. Clean any dirt or dust
from the air box.
Electrode
Leads
11. Carefully examine all seals, insulation & gaskets, replacing
as necessary. Look for any evidence of leaks or corrosion,
and if found determine & rectify the cause.
Securing Clip
12. Reassemble in reverse order, ensuring the front case
panel is securely fitted.
Gas Feed Pipe
DHW Filter (Fig. 48)
13. If the flow of domestic hot water is diminished, it may
be necessary to clean the filter.
14. Turn the DHW isolation cock (Fig. 47) off and draw off
from a hot tap.
15. Remove the retaining clip and extract the filter cartridge
and rinse thoroughly in clean water. Reassemble and check
the flow.
16. Recommission the boiler as described in Section 10.0.
Control Box removed
for clarity
17. Complete the relevant Service Interval Record section of
the Benchmark Commissioning Checklist at the rear of this
publication and then hand it back to the user.
Filter
Cartridge
View underneath
appliance
Clip
Fig. 48
Fig. 47
Inlet/Return Manifold
DHW Isolation
Cock
© Baxi Heating UK Ltd 2016
33
13.0 Changing Components
IMPORTANT: When changing components ensure that both
the gas and electrical supplies to the boiler are isolated before
any work is started. When the component has been changed
recommission the boiler as described in Section 10.0.
Always examine any seals or gaskets, replacing where
necessary. The Case Front Panel MUST seal effectively against
the air box side panels.
Spark Ignition
Electrode
See Section 12.1 “Annual Servicing” for removal of case panel,
door etc.
Electrode
Leads
13.1
Flame Sensing
Electrode
Spark Ignition & Flame Sensing Electrodes (Fig. 49)
1. Disconnect the electrode leads, noting their positions.
2. Remove the retaining screws securing each of the electrodes
to the combustion box cover and remove the electrodes.
Fig. 49
3. Check the condition of the sealing gaskets and replace if
necessary. Reassemble in reverse order.
4. After changing the Flame Sensing Electrode check the
combustion - see Section 14.1.
5. When satisfactory combustion readings are not obtained
ensure the electrode position is correct and perform the
combustion check again.
Control Box removed
for clarity
13.2
Fan (Fig. 50)
1. Remove the clip securing the gas feed pipe to the air/gas
venturi. Disconnect the pipe.
Cover
2. Undo the screws securing the air/gas collector to the extension
piece and disconnect the fan electrical plugs (Fig. 50).
Gasket
3. Remove the collector and fan assembly, being careful to retain
the gasket.
Air/Gas
Collector
4. Undo the screws securing the fan to the collector. Retain the
gasket.
5. Undo the screws securing the venturi to the fan (noting its
position) and transfer to the new fan, replacing the seal if
necessary.
Air/Gas
Venturi
6. Examine the gasket(s) and replace if necessary.
7. Reassemble in reverse order and perform the Calibration
Function - see Section 14.2.
Fan
Fig. 50
Clip
Gas Feed Pipe
13.3
Air/Gas Venturi (Figs. 50 & 51)
1. Remove the clip securing the gas feed pipe to the venturi.
2. Undo the screws securing the collector to the extension piece
and disconnect the fan electrical plugs.
3. Remove the collector and fan assembly, being careful to retain
the gasket.
4. Undo the screws securing the venturi to the fan (noting its
position) and fit the new venturi, replacing the seal if necessary.
Venturi
Gasket
Fan
34
© Baxi Heating UK Ltd 2016
Fig. 51
5. Examine the gasket and replace if necessary.
6. After changing the venturi check the combustion - see Section
14.1.
Cover
13.0 Changing Components
Burner
13.4
Gasket
Burner (Fig. 52)
1. Remove the clip securing the gas feed pipe to the air/gas
venturi and disconnect the fan electrical plugs.
Extension Piece
2. Undo the screws securing the air/gas collector to the
extension piece. Note its orientation and remove the
extension piece (where fitted) from the cover.
Gasket
3. Undo the screws securing the burner. Withdraw the
burner from the cover and replace with the new one.
Fig. 52
4. Examine the gasket(s), replacing if necessary.
Note: Where the extension piece is fitted the two
gaskets are not the same !
5. After changing the burner check the combustion. - see
Section 14.1.
Air/Gas
Collector
13.5
Insulation (Fig. 53)
1. Remove the clip securing the gas feed pipe to the air/gas
venturi and disconnect the fan electrical plugs.
2. Remove the electrodes as described in section 13.1.
3. Undo the nuts holding the cover to the heat exchanger.
Draw the air/gas collector, fan and cover assembly away.
4. Remove the cover insulation piece.
Control Box removed
for clarity
5. Fit the new insulation carefully over the burner and align
it with the slots for the electrodes.
6. If the rear insulation requires replacement, remove it and
all debris from the heat exchanger. Also it may be necessary
to separately remove the spring clip from the pin in the
centre of the heat exchanger and the ‘L’ shaped clips
embedded in the insulation.
Heat
Exchanger
Rear
Insulation
7. Do not remove the shrink-wrapped coating from the
replacement rear insulation. Keep the insulation vertical and
press firmly into position.
Air/Gas
Collector
8. Examine the cover seal and replace if necessary.
Reassemble in reverse order.
Spark Ignition
Electrode
Cover
Insulation
Seal
Fig. 53
Electrode
Leads
Flame Sensing
Electrode
© Baxi Heating UK Ltd 2016
35
13.0 Changing Components
13.6
Electrical
Plug
Flue Sensor (Fig. 54)
1. For ease of access remove the Expansion Vessel as
described in Section 13.22.
Flue Sensor
2. Ease the retaining tab on the sensor away and disconnect
the electrical plug.
3. Turn the sensor 90° anticlockwise to remove - it is a
bayonet connection.
4. Reassemble in reverse order.
Fig. 54
13.7
Heating Flow & Return Sensors (Fig. 55)
1. There is one sensor on the flow (red wires) and one
sensor on the return (blue wires). Note: For access to the
return sensor first remove the fan and air/gas collector (see
13.2).
2. After noting the position prise the sensor clip off the pipe
and disconnect the plug.
3. Connect the plug to the new sensor and ease the clip onto
the pipe as close to the heat exchanger as possible.
13.8
Control Box removed
for clarity
Safety Thermostat (Fig. 55)
1. Pull the plug off the safety thermostat.
2. Remove the screws securing the thermostat to the
mounting plate on the flow pipe.
Heating Flow Sensor
3. Reassemble in reverse order, ensuring that the plug is
pushed fully on.
13.9
DHW NTC Sensor (Fig. 56)
1. Turn off the mains cold water supply tap and draw off the
residual domestic hot water.
Safety Thermostat
2. Ease the retaining tab on the sensor away and disconnect
the electrical plug.
3. Remove the retaining clip and withdraw the sensor from
the hydraulic outlet assembly. Examine the ‘O’ ring, replacing
if necessary.
Fig. 55
4. Reassemble in reverse order. The plug will only fit one way.
Retaining Clip
Fig. 56
DHW NTC Sensor
36
© Baxi Heating UK Ltd 2016
13.0 Changing Components
13.10
Pump - Complete (Fig. 58)
1. Disconnect the electrical supply plugs from the pump.
2. Close the flow and return isolation taps and drain the
boiler primary circuit. For ease of access remove the
heating pressure gauge (13.14) & diverter valve motor
(13.19).
3. Undo the three screws securing the body to the inlet
assembly and pump flow pipe. Draw the complete
pump forwards.
4. Remove the automatic air vent and transfer to the
new pump body.
5. Examine the ‘O’ ring seals, replacing if necessary and
reassemble in reverse order.
Control Box removed
for clarity
13.11
Automatic Air
Vent
Pump Flow
Pipe
Automatic Air Vent (Fig. 58)
1. See Section 13.21 to remove the expansion vessel.
Close the flow and return isolation taps and drain the
primary circuit.
2. The automatic air vent is a bayonet fitting. Remove by
twisting anticlockwise.
3. Fit the new automatic air vent, ensuring the ‘O’ ring is
fitted and the cap is open . Reassemble in reverse order.
Fig. 58
© Baxi Heating UK Ltd 2016
37
13.0 Changing Components
Clip
13.12
Safety Pressure Relief Valve (Fig. 59)
1. Close the flow and return isolation taps and drain the
primary circuit.
‘O’ Ring Seal
2. For access remove the screws securing the
condensate trap, and pull off the pipe from the heat
exchanger. Ease the trap to one side.
Pressure Relief
Valve
3. Disconnect the discharge pipe from the pressure relief
valve and remove the sealing grommet.
Discharge Pipe
4. Pull off the clip retaining the valve and withdraw it
from the outlet assembly.
Fig. 59
5. Fit the new valve and ‘O’ ring seal and reconnect the
discharge pipe. Ensure the grommet is in place to
maintain the integrity of the case seal. Refit the
condensate trap.
13.13
Heating Pressure Gauge (Figs. 60 & 61)
1. Close the flow and return isolation taps and drain the
primary circuit.
2. Remove the gauge from the boiler lower panel.
3. Remove the clip securing the pressure gauge capillary.
4. Fit the new gauge, ensuring that the capillary is routed
to prevent any sharp bends. Reassemble in reverse order
and ensure the gauge is firmly in position to maintain the
integrity of the case seal.
Control Box removed
for clarity
Heating
Pressure
Gauge
Heating Pressure
Gauge Capillary
Clip
Fig. 60
Fig. 61
38
© Baxi Heating UK Ltd 2016
13.0 Changing Components
13.14
Plate Heat Exchanger (Fig. 62)
1. Close the flow & return isolation taps and the cold
mains inlet. Drain the primary circuit and draw off any
residual DHW.
2. Refer to Annual Servicing Section 12.2 paragraphs 5
to 8 and remove the fan etc.
Plate Heat
Exchanger
3. Undo the screws securing the plate heat exchanger
to the hydraulic assembly.
R.H. Stud -
4. Withdraw the plate heat exchanger upwards and to
the left to remove.
Note offset
Seals
5. There are four rubber seals between the hydraulic
assembly and heat exchanger which may need
replacement.
Control Box removed
for clarity
Rubber Seal
6. Ease the seals out of the hydraulic assembly. Replace
carefully, ensuring that the seal is inserted parallel and
pushed fully in.
7. When fitting the new heat exchanger note that the
right hand location stud is offset towards the centre
(Fig. 62).
Fig. 62
8. Reassemble in reverse order.
Hydraulic Pressure
Sensor
13.15
Hydraulic Pressure Sensor
(Fig. 63)
1. Close the flow and return isolation taps and drain the
primary circuit. Remove the fan and collector assembly.
Plug
2. Remove the plug from the sensor and pull the
retaining clip forwards. The clip is captive and does not
need to be fully removed.
3. Reassemble in reverse order.
Fig. 63
Securing Clip
(captive)
Plate Heat Exchanger
Securing Screws
© Baxi Heating UK Ltd 2016
Pump, Gas Valve
Assemblies and Pipework
removed for clarity
39
13.0 Changing Components
13.16
DHW Flow Regulator & Filter (Fig. 64)
1. Remove the Fan & Collector (13.2). Close the cold
mains inlet and draw off any residual DHW.
2. Pull out the securing clip and prise the regulator and
filter assembly out of the hydraulic inlet assembly.
3. Twist the body to unlock the bayonet connection
and remove the regulator.
4. Examine and clean the filter, and reassemble in
reverse order.
13.17
Control Box removed
for clarity
DHW Flow Sensor (‘Hall Effect’ Sensor)
(Fig. 65)
1. Pull the sensor off the DHW inlet manifold.
DHW Flow Sensor
(‘Hall Effect’ Sensor)
DHW Flow
Regulator & Filter
2. Disconnect the plug from the sensor and connect it
to the new component.
3. Fit the new sensor, ensuring it is correctly oriented
and fully engaged over the manifold.
Fig. 64
13.18
Diverter Valve Motor (Fig. 66)
1. Undo the screw securing the electrical plug to the
motor unit. Disconnect the plug.
Fig. 65
2. For ease of access remove the pressure gauge and
sealing grommet from the boiler bottom panel.
3. Hold the motor in place against the spring pressure
of the valve and remove the securing clip.
4. Remove the motor.
5. When fitting the new motor it will be necessary to
hold the unit firmly while depressing the valve return
spring.
14.25
Pump, Gas Valve
Assemblies and Pipework
removed for clarity
Securing
Clip
Electrical Plug
Fig. 66
40
© Baxi Heating UK Ltd 2016
Diverter Valve
Motor
13.0 Changing Components
13.19
P.C.B. & R.D.S. (Removable Data Stick)
(Fig. 64)
NOTE: Both P.C.B. and R.D.S. are available as spare parts.
The P.C.B. is suitable for any boiler model. An R.D.S. specific
to the boiler model output & gas type will be required if the
R.D.S. from the original P.C.B. is not being transferred. It is
recommended that P.C.B. and R.D.S. are replaced together.
1. Ensure that the power to the boiler is isolated and wait 10
seconds.
2. Remove the screws securing the control box cover and
release the cover retaining barbs from their slots.
3. Note the position of all plugs and wires on the P.C.B. and
disconnect them.
4. Undo the securing screws and remove the P.C.B.
IMPORTANT: If only the P.C.B. is being replaced transfer
the R.D.S. from the original board to the new one. Where
both P.C.B. and R.D.S. are being replaced ensure the new
R.D.S. is on new the board.
Fig. 67
Slot for Ignition Lead
R.D.S.
5. Reassemble in reverse order. Ensure that the ignition lead is
connected correctly.
6. P.C.B. ONLY changed - Check the Combustion - see
Section 14.1.
7. P.C.B. & R.D.S. changed - enable the Calibration Function as
described in Section 14.2, then Check the Combustion - see
Section 14.1.
Note the correct
orientation of the R.D.S.
Position with the chamfer
as shown.
X24
X20
X22
X1
X36
X2
X37
X23
X3
© Baxi Heating UK Ltd 2016
X10
X13
X11
X12
41
Gas Feed
Pipe
NOTE: The Injector Washer MUST
be fitted as shown between the
Valve & Pipe. DO NOT fit the
Injector Washer between the Gas
Cock & Valve
13.0 Changing Components
13.20
Gas Valve (Fig. 68)
IMPORTANT: After replacing the valve the CO2 must be
calibrated as detailed in Section 14.0 Combustion &
Calibration. Only change the valve if a suitable calibrated
combustion analyser is available, operated by a
competent person - see section 12.1.
Injector
Washer
Gas Valve
Electrical Plug
1. Turn the gas cock off and undo the nut under the boiler.
Retain the washer.
2. Remove the electrical plug from the valve.
3. Undo the nut on the gas feed pipe and ease the pipe aside.
It is recommended that the injector washer is changed as well.
Washer
Gas Cock
4. Remove the screws securing the gas valve to the boiler
bottom panel.
5. Reassemble in reverse order, ensuring the injector washer is
in place, and perform the Calibration Function & Combustion
Check - see Sections 14.1 & 14.2.
Fig. 68
NOTE: Check for gas tightness after replacing gas valve.
13.21
Expansion Vessel (Fig. 69)
1. Close the flow and return isolation taps and drain the
primary circuit.
Lock Nut
2. Prise off the securing clip and disconnect the braided hose
from the vessel.
3. Whilst supporting the vessel undo the locknut and
manoeuvre the vessel out of the boiler.
4. Reassemble in reverse order.
Expansion
Vessel
Fig. 69
42
© Baxi Heating UK Ltd 2016
14.0 Combustion & Calibration
IMPORTANT: DO NOT insert the Analyser
Probe into the Test Point immediately. This will
prevent saturation of the analyser.
During the Calibration Function the combustion
ratio may increase for a short time while the
boiler performance is optimised.
14.1
Checking the Combustion
1. Combustion should be:Natural Gas 9.0% CO2 ± 0.7
Propane 10.5% CO2 ± 1.0
at all 3 fan speeds:- ‘100’ (Maximum), the Ignition Phase speed
and ‘00’(Minimum).
2. Press
&
together and hold for at least 6
seconds. ‘On’ will be displayed briefly, followed by ‘304’ then
the boiler CH output expressed as percentage i.e. ‘100’. It may
be necessary to open one or more hot taps in order to maintain
the boiler at full rate.
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.
The flue gas analyser used should be one meeting
the requirements of BS7927 or BS-EN50379-3
and be calibrated in accordance with the analyser
manufacturers’ requirements.
3. Insert the analyser probe and once stabilised note the CO2
reading.
4. Press
to select the Ignition Phase Speed. A value will
be displayed, e.g. ‘33’. Note the CO2 reading.
5. Press
again to select the Minimum Output. ‘00’ will
be displayed. Note the CO2 reading.
Flue Sampling
Point
6. If the CO2 is not within the tolerances referred to above at
any of the speeds, follow the procedure in Section 14.3
opposite to calibrate the boiler.
Plug
Analyser Probe
Fig. 70
7. To exit the function press
seconds.
&
together for 6
Air Sampling
Point
14.2
Calibration Function
IMPORTANT: Do not commence the Calibration Function
whilst the burner is lit ! The case front panel MUST be fitted.
14.3
Adjusting the CO2
1. Press
&
together and hold for at least 6
seconds. ‘On’ will be displayed briefly, followed by ‘304’ then
the boiler CH output expressed as percentage i.e. ‘100’.
2. Press
to select the adjustment function. ‘0’ will alternate
&
buttons adjust ‘0’
with ‘304’. Using the
between ‘-3’ & ‘3’.
3. Decreasing the value lowers the CO2, and selecting a higher
value will increase CO2.
4. Once the correct CO2 reading is achieved press
return to the fan speed selection.
to
5. Using
or
to select the next fan speed. ‘00’
indicates MINIMUM speed, the other speed (Ignition Phase) will
be indicated by, for example ‘33’ (this varies depending on
boiler model).
6. Repeat step 2. above to adjust the CO2.at Ignition Phase and
Minimum fan speeds. Press
&
together and hold
for at least 6 seconds to exit the function.
NOTE: To obtain an accurate measurement on smaller
capacity systems it may be necessary to open one or more
hot taps in order to maintain the boiler at full rate.
1. The function is activated by pressing buttons
and
R together for 6 seconds then quickly pressing button
while ‘On’ is displayed. The Ignition Phase fan speed code will
then be displayed. Calibration will take approximately 5 minutes.
2. If ‘303’ is displayed, then the Calibration Function has not
been activated correctly. Isolate and reinstate all power sources
to the boiler and repeat the above.
3. The boiler will automatically calibrate at ‘100’, the Ignition
Phase speed then ‘00’. These represent the percentage of
MAXIMUM fan speed (i.e. ‘00’ is MINIMUM fan speed). Once
the boiler has stabilised and self-calibrated at each fan speed the
and
symbols will be displayed before the next speed is
automatically set.
4. When self-calibration is complete the boiler will run at
MINIMUM fan speed (‘00’displayed). The following symbols will
also be displayed
flashing together at regular
intervals.
5. To exit the function press
R . ‘ESC’ will be displayed and
the calibration function completed.
© Baxi Heating UK Ltd 2016
43
15.0 Electrical
15.1
Illustrated Wiring Diagram
Gas
Valve
Hall Effect
Sensor
Fan
Flue Sensor
Hydraulic
Pressure
Switch
Safety
Thermostat
Heating
Return
Sensor
b
b
w
b
Heating
Flow
Sensor
DHW
NTC
Sensor
r
bk
r
g
b
b
g
b
br bk
b
Terminal Strip
br
X37
w
g br
b
X36
r
b r
X22
g
g
br
X20
br
X24
X10
g/y
b
b
X23
X3
bk
b
bk
br
X13
b
bk
br
M2
Low Voltage
External Control
Connection
X31
br
b
br
b
X11
g/y
X12
X1
X2
br
b
g/y
g/y
g/y
Spark
Ignition
Electrode
Pump
Diverter Valve
Motor
Key To Wiring Colours
b - Blue
r - Red
bk - Black
g - Green
br - Brown
g/y - Green/Yellow
w - White
y - Yellow
gr - Grey
44
© Baxi Heating UK Ltd 2016
bk
Flame
Sensing
Electrode
16.0 Short Parts List
Short Parts List
B
A
C
D
Key
No.
Description
No.
Manufacturers
Part No.
A
Fan
720768101
B
Burner
7225221
C
Spark Ignition Electrode
720767301
D
Flame Sensing Electrode
720767101
E
Gas Valve
720752301
F
Safety Thermostat
720765301
G
Hall Effect Sensor
720061801
I
Plate Heat Exchanger
720852401
J
Diverter Valve Motor
720776801
K
Pump
7220533
M
Heating Flow/Return Sensor
720747101
N
DHW NTC Sensor
720777001
O
Pump Automatic Air Vent
720777601
P
Hydraulic Pressure Switch
720778001
Q
Heating Pressure Gauge
720776601
R
Flue Sensor
5114747
S
PCB only
720878202
T
R.D.S. - 24
720841401
E
G
F
J
I
N
M
K
P
O
U
V
R.D.S. - 28
720841701
R.D.S. - 24 LPG
720842301
R.D.S. - 28 LPG
720842601
Injector Washer - 24 (Ø 4.4)
720751701
Injector Washer - 28 (Ø 4.6)
720775801
Air/Gas Venturi
720768301
S
Q
R
U
T
V
© Baxi Heating UK Ltd 2016
45
Table Of Error Codes
09
Gas Valve Connection Cable
15
Gas Valve Fault
20
Central Heating NTC Fault
28
Flue NTC Fault
40
Central Heating Return NTC Fault
55
Calibration Required
109
Pre-circulation Fault
110
Safety Thermostat Operated
117
Primary System Water Pressure Too High
118
Primary System Water Pressure Too Low
125
Circulation Fault (Primary)
128
Flame Failure
130
Flue NTC Operated
133
Interruption Of Gas Supply or Flame Failure
134
Elapsed Time - Gas Valve Open Without Gas
135
Interruption Of Gas Supply (Internal Error)
154
Flow/Return Sensor Temperature Test
160
Fan or Fan Wiring Fault
270
Circulation Fault (Dry Fire)
321
Hot Water NTC Fault
384
False Flame
17.0 Fault Finding & ‘Service Due’
17.1
1. Check that gas, water and electrical supplies are available at
the boiler.
2. Electrical supply = 230V ~ 50 Hz.
3. The preferred minimum gas pressure is 20 mb (NG) 37mb
(LPG)
4. Carry out electrical system checks, i.e. Earth Continuity,
Resistance to Earth, Short Circuit and Polarity with a suitable
meter.
NOTE: These checks must be repeated after any servicing or
fault finding.
5. Ensure all external controls are calling for heat and check all
external and internal fuses. Before any servicing or replacement
of parts, ensure the gas and electrical supplies are isolated.
17.2
The
button can be pressed so that the display shows the following
information:1 press - ‘00’ alternates with Sub-Code (only when fault on boiler) or ‘000’
2 presses - ‘01’ alternates with CH Temperature
3 presses - ‘02’ alternates with Outside Temperature (where Sensor fitted)
4 presses - ‘03’ alternates with DHW Temperature
5 presses - ‘04’ alternates with DHW Temperature
6 presses - ‘05’ alternates with System Water Pressure
7 presses - ‘06’ alternates with Return Temperature
8 presses - ‘04’ alternates with Flue Temperature
9 presses - ‘05’ alternates with Heat Exchanger Temperature
1. After 11 months operation the ‘Service Due’ message will
be shown on the boiler display. (If the installation has been
subject to prolonged electrical isolation or power cuts this
period may be longer than 11 months)
2. Once the service has been completed satisfactorily the
‘Service Due’ message can be reset or de-activated.
5. Press
to scroll to ‘15’. Confirm with
press R to return the display to normal.
To De-activate
6. Press
&
for 6 seconds. Using
.
through until ‘22’ is displayed. Press
46
7. Press
Using
until ‘22’ is displayed again. Press
.
scroll through to ‘50’. Press
8. Press
then press
R to return the display to normal.
© Baxi Heating UK Ltd 2016
until ‘25’ is displayed. Confirm with
Error Codes
1. If a fault occurs on the boiler an error code may be shown by
the facia display.
2. The codes are a flashing number, either two or three digit,
preceded by the symbol :followed by 20, 28, 40, 160 or 321 indicates possible faulty
components.
followed by 55 (after replacing R.D.S.) indicates calibration
required (Section 14.2).
110 indicates overheat of the primary system water.
‘Service Due’ Message
To Reset
4. Press
&
for 6 seconds. Using
.
through until ‘22’ is displayed. Press
Initial Fault Finding Checks
scroll
then
scroll
.
117 is displayed when the primary water pressure is greater than
2.7 bar.
118 is displayed when the primary water pressure is less than 0.5
bar.
133, 134 and 135 indicate that the gas supply has been
interrupted, ignition has failed or the flame has not been detected.
128 is displayed if there has been a flame failure during normal
operation.
125 is displayed in either of two situations:i) If between 15 and 30 seconds of the burner lighting the boiler
temperature has not changed by 1°C.
ii) If within 10 minutes of the burner lighting the boiler actual
temperature twice exceeds the selected temperature by 30°.
In these instances poor primary circulation is indicated.
3. By pressing the 'Reset' button for 1 to 3 seconds when
110, 125, 133, 134, 135, 09, 15, 128 & 384 are displayed it is
possible to relight the boiler.
4. If this does not have any effect, or the codes are displayed
regularly further investigation is required.
17.0 Fault Finding
Refer to “Illustrated Wiring Diagram” for position of terminals and components
Central Heating - Follow operational sequence
Turn on mains power
The display illuminates
NO
If
09, 15, 110 or 384 is flashing or re-occurs
regularly, check all PCB connections. If this has no
effect replace the PCB.
Go to section ‘A’
YES
09, 15, 110, 125, 133, 134,
135 or 384 flashing
YES
If
Press the reset button for 1 to
3 seconds
110 is still flashing go to
section ‘H’
NO
20, 28, 40 or 321 flashing
YES
Go to section ‘D’
NO
117 or 118 flashing
YES
Go to section ‘I’
Ensure controls are set to
demand and verify the
contacts are closed
NO
NO
Set Central Heating
temperature to Maximum.
symbol flashing, pump runs
NO
Ensure all controls and
programmers are calling for
heat
YES
Go to section ‘B’
YES
Fan runs after up to 3 minutes
NO
160 flashing
Go to section ‘C’
NO
160 flashing
Go to section ‘C’
YES
Fan runs at correct speed
YES
Spark at ignition electrodes up
to 5 seconds & for 3 attempts
NO
YES
Go to section ‘F’. Press the
reset button for 1 to 3 seconds
YES
133 flashing
Go to section ‘G’
133 flashing
YES
Go to section ‘E’
NO
Burner lights
YES
Burner goes out after 5
seconds
YES
109 flashing
YES
Go to section ‘J’
125 flashing after 1 min
NO
110 flashing
YES
Go to section ‘H’
NO
Diverter Valve open to Central
Heating circuit
NO
Go to section ‘K’
YES
Burner modulates to maintain
set temperature
NO
Check Heating Flow sensor.
Go to section ‘D’
NO
130 flashing
YES
Go to section ‘M’
NO
Burner goes out
© Baxi Heating UK Ltd 2016
YES
Fan stops after 10 seconds
YES
Boiler operation correct
47
17.0 Fault Finding
Domestic Hot Water - Follow operational sequence
Turn on mains power
The display illuminates
NO
If
09, 15, 110 or 384 is flashing or re-occurs
regularly, check all PCB connections. If this has no
effect replace the PCB.
Go to section ‘A’
YES
09, 15, 110, 125, 133, 134,
135 or 384 flashing
YES
If
Press the reset button for 1 to
3 seconds
110 is still flashing go to
section ‘H’
NO
20, 28, 40 or 321 flashing
YES
Go to section ‘D’
NO
117 or 118 flashing
YES
Go to section ‘I’
Go to section ‘L’
NO
NO
Go to section ‘L’
Set Hot Water temperature to
Maximum & fully open hot tap.
symbol flashing, pump runs
NO
NO
DHW flow rate greater than
2litres/min
YES
Burner lights
YES
YES
Fan runs after up to 3 minutes
NO
160 flashing
Go to section ‘C’
NO
160 flashing
Go to section ‘C’
NO
133 flashing
YES
Fan runs at correct speed
NO
Spark at ignition electrodes up
to 5 seconds & for 3 attempts
YES
Go to section ‘F’. Press the
reset button for 1 to 3 seconds
YES
133 flashing
Go to section ‘G’
YES
Go to section ‘E’
NO
Burner lights
YES
Burner goes out after 5
seconds
YES
109 flashing
YES
Go to section ‘J’
125 flashing after 1 min
NO
110 flashing
YES
Go to section ‘H’
NO
3 Way Valve open to
Domestic Hot Water circuit
NO
Go to section ‘K’
YES
Burner modulates to maintain
set temperature
NO
Check CH NTC sensor.
Go to section ‘D’
NO
130 flashing
YES
Go to section ‘M’
NO
Burner goes out
48
© Baxi Heating UK Ltd 2016
YES
Fan stops after 10 seconds
YES
Boiler operation correct
Go to section ‘B’
17.0 Fault Finding
Fault Finding Solutions Sections
A
Is there 230V at:
1.
2.
3.
B
Main terminals L and N
NO
Check electrical supply
NO
Main terminal fuse
Connection
OK at X10
Replace fuse
NO
Check wiring
PCB - X10 connector
Main terminals L and N
Display
illuminated
NO
Display or
Main PCB fault
Switch to DHW mode maximum flow and press reset.
During next 3 minutes check:-
YES
230V at PCB - X13 connector (between
blue & brown - see Wiring Diagram)
230V between PCB - X13 connector
(blue) and PCB - X11 connector
(black) - see Wiring Diagram
NO
NO
Replace PCB
C
YES
230V at pump
YES
Replace pump
NO
Check wiring
Replace PCB
Fan connections correct at fan & PCB
X11 and X23 connectors - see
Wiring Diagram.
NO
Make connections
YES
YES
230V at PCB - X11 connector (between
blue & brown - see Wiring Diagram)
Fan jammed or
faulty wiring
YES
Replace fan or wire
NO
Replace PCB
D
Temperature sensor faulty.
Check correct location and wiring.
YES
Cold resistance approximately
10k @ 25° C (DHW and CH sensors)
(resistance reduces with increase in temp.)
E
Gas at burner
NO
NO
Replace sensor
Ensure gas is on and purged
Check wiring and PCB - X36 connector
see Wiring Diagram
YES
Replace gas valve &
Check combustion
NO
Replace PCB
© Baxi Heating UK Ltd 2016
49
17.0 Fault Finding
Check and correct if necessary
1. Ignition electrode and lead
2. Electrode connection
3. Spark gap and position
YES
NO
Check wiring - see Diagram
Replace PCB
4 ±0.5
F
Burner
Viewing Window
Flame
Sensing
Electrode
5±
1
Spark Ignition
Electrode
10 ±1
Electrode Position
G
1.
2.
Check supply pressure at the
gas valve:Natural Gas - Minimum 17 mbar
Propane - Minimum 37 mbar
Check and correct if necessary
1. The set of the gas valve
(CO2 values - see instruction)
2. Flame sensing electrode and lead connections
3. Flame sensing electrode position
Replace sensing electrode or PCB
H
Safety Thermostat operated or
faulty
NO
Check for and correct any
system faults
NO
Allow to cool. Continuity
across thermostat terminals
more than 1.5 ohm
YES
Replace safety thermostat
NO
Check Flow & Return Sensors see section ‘D’
YES
Is
110 still flashing ?
YES
Replace PCB
50
© Baxi Heating UK Ltd 2016
17.0 Fault Finding
I
CH system pressure less than
0.5 bar or greater than 2.7 bar
NO
J
YES
Restore system pressure
YES
Check wiring and PCB - X22
connector for approx. 5V DC
between green & black - see
Wiring Diagram
Ensure that the boiler and system
are fully vented
YES
NO
Replace hydraulic pressure sensor
NO
Replace PCB
System fault - correct
Check flow temperature sensor connections
and position.
Cold resistance approximately
10k @ 25° C (CH sensors)
(resistance reduces with increase in temp.)
NO
Replace sensor
YES
Go to section ‘B’
K
Is there 230V at:
1.
PCB - X13 connector terminals between:Blue & Black (central heating mode)
Blue & Brown (domestic hot water mode)
see Wiring Diagram
NO
Replace PCB
YES
Check diverter valve motor cable
2.
L
Diverter valve motor
Is mains water filter & assembly
clean, and rotor moving freely ?
YES
YES
Replace diverter valve motor
Check wiring and PCB - X22
connector for approx. 5V DC
between red & blue from Hall
effect sensor - see Wiring Diagram
YES
Replace Hall Effect Sensor
NO
NO
Clean or replace
Replace PCB
M
1.
2.
Temperature sensors faulty.
Cold resistance approximately
10k @ 25° C (CH sensor)
20k @ 25° C (Flue sensor)
(resistance reduces with increase in temp.)
If pump is running the heat exchanger could be
obstructed
© Baxi Heating UK Ltd 2016
NO
YES
Replace sensor
Replace heat exchanger
51
18.0 Optional Outdoor Sensor
18.1
Positioning the Optional Outdoor Sensor
1. The Sensor must be fixed to an external wall surface of
the property it is serving. The wall must face a north or west.
1/2 H
2.5m Min
H
NOTE: DO NOT position it on a south facing wall in
direct sunlight !
West
North
N
E X
W
S X
2. The Sensor should be approximately half the height of the
living space of the property, and a minimum of 2.5m above
ground level.
3. It must be positioned away from any sources of heat or
cooling (e.g. flue terminal) to ensure accurate operation.
Siting the Sensor above doors and windows, adjacent to
vents and close to eaves should be avoided.
18.2
Connecting the Optional Outdoor Sensor
1. Ensure the electrical supply to the boiler is isolated. Undo
the securing screws and lift the case front panel off.
Low Voltage
Terminal Block
ODS Connection
2. Disengage the securing tab and hinge the control box
downwards. Undo the terminal block cover securing screw
and remove the cover.
3. Remove one of the grommets, pierce the diaphragm and
insert the wires from the Outdoor Sensor.
4. Leave sufficient slack in the wires to allow the Control Box
to be hinged fully open. Refit the grommet.
5. Connect the wires from the Outdoor Sensor to positions
4 & 5 on M2 as shown. Refit the cover.
18.3
Boiler Flow
Temperature
Setting the Sensor Curve
1. Ensure that there is power to the boiler.
2. The Central Heating temperature buttons
&
are used to select the desired curve as shown on the graph.
Outdoor Temperature
3. Normally the display will show the current temperature of
the water in the boiler (e.g. 41°C). As the buttons are
pressed the curve identification code the will be shown, from
‘00’ to ‘90’.
4. To select the most appropriate curve consideration must
be given to the expected outdoor temperature range. This
must then be compared to a boiler flow temperature that
will satisfy the needs of the user, e.g. If outdoor temperatures
in the range 0°C to -5°C are anticipated and a boiler flow of
no more than 60°C required, select Curve ‘20’ .
5. As a further example, if Curve ‘40’ is selected, at an
outside temperature of 5°C the boiler flow temperature will
be just below 70°C. In the event of the outside temperature
falling to 0°C, the boiler flow will increase to 80°C.
6. Continue with the installation and commissioning of the
boiler as described in the Installation & Servicing Instructions.
7. Explain to the user how to select a different temperature
curve.
52
© Baxi Heating UK Ltd 2016
18.0 External Low Voltage Controls
Optional 7 Day Wired Sensor
1. Press Securing Tab
18.4
Connecting the Optional 7 Day Wired Sensor
NOTE: The yellow link wire between terminals 1 & 2 on
terminal block M1 MUST be removed when fitting the
7 Day Wired Sensor.
2. Ease away from Backplate
1. Ensure that the power to the boiler is isolated.
2. Remove the backplate from the unit by pressing down on
the rear tab and easing apart.
3. Locate the sensor and use wiring as described in the
literature supplied with it.
4. Pass the wiring through the slots in the backplate and
connect as shown opposite to 2 & 3 on the sensor backplate
and 1 & 2 of boiler terminal M2.
5. Complete fitting as described in the sensor literature, turn
the power back on and set the controls to the requirements of
the user.
Boiler Wiring
Terminal M2
Low Voltage
Terminal Block
1
2
Programmer & Room
Sensor Backplate
} RT/OT - Room Thermostat/Open Therm
Connection
3
4
5
} ODS - Outdoor Sensor Connection
6
1 2 3
7
8
9
10
1
IMPORTANT !
When fitting Low
Voltage Controls
remove the Yellow Link Wire
from the Boiler Terminal Block M1
© Baxi Heating UK Ltd 2016
Boiler
Mains Voltage
Terminal Block M1
2
3
N
4
L
5
53
18.0 External Low Voltage Controls
Optional 7 Day Wireless Sensor &
24hr Wireless Sensor
18.5
1. Press Securing Tab.
Connecting the Optional 7 Day Wireless Sensor
& 24hr Wireless Sensor (kit includes a Sensor &
Receiver - the Receiver is wired into the boiler).
NOTE: The yellow link wire between terminals 1 & 2 on
terminal block M1 MUST be removed when fitting the
7 Day Wireless Sensor & 24hr Wireless Sensor.
2. Ease Backplate away.
1. Ensure that the power to the boiler is isolated.
2. Remove the backplate from the receiver unit by pressing
down on the rear tab and easing apart.
3. Locate the receiver and use wiring as described in the
literature supplied with it.
4. Pass the wiring through the slots in the backplate and
connect as shown opposite to the OT connection on the
receiver backplate and 1 & 2 of boiler terminal M2.
5. Complete fitting as described in the sensor/receiver
literature, turn the power back on and set the controls to the
requirements of the user.
Boiler Wiring
Terminal M2
Low Voltage
Terminal Block
1
2
} RT/OT - Room Thermostat/Open Therm
Connection
3
4
5
6
OT
7
8
9
10
1
OT
Boiler
Mains Voltage
Terminal Block M1
2
IMPORTANT !
When fitting Low
Voltage Controls
remove the Yellow Link Wire
from the Boiler Terminal Block M1
54
© Baxi Heating UK Ltd 2016
3
N
4
L
5
Notes
© Baxi Heating UK Ltd 2016
55
Notes
56
© Baxi Heating UK Ltd 2016
Notes
© Baxi Heating UK Ltd 2016
57
GAS BOILER SYSTEM 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:
Gas rate
m³/hr
Burner operating pressure (at maximum rate)
mbar OR Gas inlet pressure at maximum rate
OR
ft³/hr
mbar
Cold water inlet temperature
°C
Yes
Hot water has been checked at all outlets
Temperature
°C
I/min
CONDENSING BOILERS ONLY
The condensate drain has been installed in accordance with the manufacturer’s instructions and/or BS5546/BS6798
Yes
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.
58
© Heating and Hotwater Industry Council (HHIC)
www.centralheating.co.uk
SERVICE RECORD
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:
At max. rate:
Gas safe register No:
CO
ppm
AND
At min. rate: (Where Possible) CO
ppm
AND
CO² %
CO² %
Record:
At max. rate:
CO
ppm
AND
At min. rate: (Where Possible) CO
ppm
AND
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:
At max. rate:
ppm
AND
At min. rate: (Where Possible) CO
ppm
AND
CO² %
CO² %
Record:
At max. rate:
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:
ppm
AND
At min. rate: (Where Possible) CO
ppm
AND
CO² %
CO² %
Record:
At max. rate:
CO
ppm
AND
ppm
AND
Comments:
Signature
Signature
SERVICE 07
Date:
SERVICE 08
Engineer name:
Engineer name:
Company name:
Company name:
Telephone No:
Telephone No:
Gas safe register No:
ppm
AND
At min. rate: (Where Possible) CO
ppm
AND
CO² %
CO² %
Record:
At max. rate:
Date:
CO
ppm
AND
At min. rate: (Where Possible) CO
ppm
AND
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 %
Gas safe register No:
CO
At max. rate:
Date:
At min. rate: (Where Possible) CO
Comments:
Record:
CO² %
CO² %
Gas safe register No:
CO
At max. rate:
Date:
At min. rate: (Where Possible) CO
Comments:
Record:
CO² %
CO² %
Gas safe register No:
CO
At max. rate:
Date:
CO² %
CO² %
Date:
Gas safe register No:
CO
ppm
AND
At min. rate: (Where Possible) CO
ppm
AND
CO² %
CO² %
Record:
At max. rate:
CO
ppm
AND
At min. rate: (Where Possible) CO
ppm
AND
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)
www.centralheating.co.uk
59
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
0086
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.
7659607-01 (5/16)