United Kingdom
en
Installation and Service Manual
Condensing Combination Boiler
Titanium Combi
24 - 28 - 33 - 40
These instructions include the Benchmark Commissioning Checklist
and should be left with the user for safe keeping.
© Baxi Heating UK Ltd 2015
Natural Gas
Potterton Titanium 24 Combi ErP
G.C.No 47-393-50
Potterton Titanium 28 Combi ErP
G.C.No 47-393-51
Potterton Titanium 33 Combi ErP
G.C.No 47-393-52
Potterton Titanium 40 Combi ErP
G.C.No 47-393-53
Warning
Building Regulations and the Benchmark Commissioning
Checklist
Building Regulations (England & Wales) require notification of
the installation of a heating appliance to the relevant Local
Authority Building Control Department. From 1 April 2005 this
can be achieved via a Competent Persons Self Certification
Scheme as an option to notifying the Local Authority directly.
Similar arrangements will follow for Scotland and will apply in
Northern Ireland from 1 January 2006.
The Health & Safety Executive operates the ‘Gas Safe Register’,
a self-certification scheme for gas heating appliances.
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.
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Benchmark Logbook is being withdrawn.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.
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.
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.
© 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.
The flowchart opposite gives guidance for installers on the
process necessary to ensure compliance with Building
Regulations.
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:
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.
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
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.
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.
Warning - Check the information on the data plate is compatible with local supply
conditions.
All systems must be thoroughly flushed and treated with
inhibitor (see section 6.2).
Homologations
Codes of Practice - refer to the most recent version
CE Marking
EC - Declaration of Conformity
Baxi Heating UK Limited being the manufacturer / distributor within the European
Economic Area of the following
Potterton Titanium 24 - 28 - 33 - 40 ErP
declare that the above is in conformity with the provisions of the Council Directive
2009/142/EC 92/42/EEC 2004/108/EC 2006/95/EC
2009/125/EC
2010/30/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
In GB the following Codes of Practice apply:
Standard
Scope
BS 6891
Gas Installation.
BS 5546
Installation of hot water supplies for domestic
purposes.
BS EN 12828
Heating systems in buildings.
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
22
9.0
Installation
24
10.0
Commissioning
30
11.0
Completion
34
12.0
Servicing
35
13.0
Changing Components
37
14.0
Setting the Gas Valve
46
15.0
Electrical
47
16.0
Short Parts List
48
17.0
Fault Finding
49
18.0
Notes
55
Benchmark Checklist
58
1.0 Introduction
1.1
Case Front Panel
Description
1. The Potterton Titanium Combi ErP is a fully automatic gas
fired wall mounted condensing combination boiler. It is 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 kW CH Pnc (Condensing)
28 models - 28 kW DHW
25.9 kW CH Pnc (Condensing)
33 models - 33 kW DHW
30.3 kW CH Pnc (Condensing)
40 models - 40 kW DHW
34.4 kW CH Pnc (Condensing)
3. It is designed for use on Natural Gas (G20).
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 inner
door panel or the control box. It is visible when the case front
panel is removed (Fig. 1).
Control Box
6. The boiler model name and serial number are also shown on
the information label on the back of the facia door. This is for
user reference.
Facia Door
Fig. 1
Data Badge
Information Label
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 the standard horizontal flue kit, part no.
5118489.
9. All systems must be thoroughly flushed and treated with
inhibitor (see section 6.2).
Important: If the boiler is installed at a high point in the
system it is strongly recommended that Automatic Air Vent
Kit 720004701 is fitted.
1.2
Contents of Pack
1. Boiler Unit (with integral timer)
2. Wall Plate (inc. taps)
3. Set of Pipes (inc. nuts)
4. Template & Quick Fit Guide
5. Literature Pack
6. Filling Loop
© Baxi Heating UK Ltd 2016
7
2.0 General Layout
28a
2.1
Layout
23
1
15
22
1.
Expansion Vessel
2.
Automatic Air Vent
3.
DHW Plate Heat Exchanger / Automatic Bypass
4.
Circulation Pump
(NOTE: The boiler can be fitted with one of two alternative
pumps, Grundfos or Wilo. All boiler illustrations show
Grundfos. Section 13.14 details both types).
14
13
28
16
21
5.
Drain Off Point
6.
Pressure Relief Valve
7.
Integral Timer Position
8.
Central Heating System Pressure Gauge
9.
PCB
10.
Control Box
11.
3-Way Valve Assembly
12.
Condensate Trap
13.
Flame Sensing Electrode
14.
Spark Electrode
15.
Primary Heat Exchanger
16.
Fan Assembly
17.
On/Off/Reset Selector Switch
18.
Central Heating Temperature Control
19.
Hot Water Temperature Control
20.
Venturi
21.
Air/Gas Collector
22.
Combustion Box Cover & Burner
23.
Igniter
24.
Burner On Light
25.
Central Heating Mode Light
26.
Domestic Hot Water Mode Light
27.
Display
28.
Air Pressure Switch - 24/28/33
28a.
Air Pressure Switch - 40
29.
Pump PCB
20
10
29
9
8
7
12
2
11
3
5
4
6
25
26
2
1
12
11
3
5
7
10
9
0
4
11
18
19
8
12
© Baxi Heating UK Ltd 2016
24
1
8
27
7
2
17
3
bar
5
4
0
AM
8
3
7
1
8
PM
9
Reset
10
4
2
3.0 Appliance Operation
1
3.1
Central Heating Circuit
Central Heating Mode (Fig. 2)
1. With a demand for heating, the pump circulates water
through the primary circuit.
2
3
4
7
26
20
5
6
25
24
18
2. Once main burner ignites the fan speed controls the gas
rate to maintain the heating temperature measured by the
temperature sensor.
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.
8
4. When the demand is satisfied the burner is extinguished
and the pump continues to run for a period of 3 minutes
(Pump Overrun).
22
9
11
23
21
3.2
10
17
16
15
14
13
12
Fig. 2
Key
1
2
3
4
5
6
7
8
9
10
11
12
13
14
Primary Heat Exchanger
Burner
Ignition Electrodes
Flame Sensing Electrode
Gas Valve
Pump
Automatic Air Vent
Plate Heat Exchanger/Automatic By-pass
Flow Sensor with Filter & Regulator
Pressure Relief Valve
Boiler Drain Point
Heating Return
Cold Water Inlet On/Off Valve and Filter
Gas Inlet
15
16
17
18
20
21
22
23
24
25
26
Domestic Hot Water Outlet
Heating Flow
Pressure Gauge
Water Pressure Sensor
Fan
Diverter Valve Assembly
Diverter Valve Motor
Domestic Hot Water Flow Temperature Sensor
Safety Thermostat
Central Heating Temperature Sensor
Expansion Vessel
1. Priority is given to the domestic hot water supply. A
demand at a tap or shower will override any central heating
requirement.
2. The flow of water will operate the 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.
3. The burner will light automatically and the temperature of
the domestic hot water is controlled by the temperature
sensor.
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.
IMPORTANT: When the selector switch is in the ‘0’
(Off) position the electrical supply to the boiler is isolated.
The boiler will not operate and the integral timer will
require resetting once the selector switch is set to either
Position (i) or Position (ii).
1
Domestic Hot Water Circuit
3.3
2
3
4
7
26
20
5
6
25
24
18
22
9
11
23
10
Frost Protection Mode
1. The frost protection mode is integral to the appliance and
functions only with the selector switch (see Section 2.1) in
the domestic hot water and central heating position. If the
system temperature falls below 5° C then the boiler will fire
on its minimum setting until a flow temperature of 30° C is
reached. Further protection can be incorporated by using a
system frost thermostat.
3.4
8
21
Domestic Hot Water Mode (Fig. 3)
Pump Protection
1. With the selector switch (see Section 2.1) in either the
central heating or central heating and domestic hot water
position, the pump will automatically operate for 1 minute in
every 24 hours to prevent sticking.
17
16
15
14
13
12
Fig. 3
© Baxi Heating UK Ltd 2016
9
4.0 Technical Data
4.1
Appliance Type
C13
Appliance Category
C33
C53
CAT I 2H
24 model
28 model
33 model
40 model
kW
kW
kW
kW
Min
7.8
10.0
10.8
11.0
Heat Output CH Pn (Non-Condensing)
Max
Min
24 model
kW
20.0
6.8
28 model
kW
24.0
8.7
33 model
kW
28.0
9.4
40 model
kW
32.0
9.6
Heat Output CH Pnc (Condensing)
Max
24 model
kW
21.0
28 model
kW
25.9
33 model
kW
30.3
40 model
kW
34.4
Heat Input Qnw Hs DHW (Gross)
24 model
kW
27.4
28 model
kW
32.1
33 model
kW
37.7
40 model
kW
45.7
Heat Output DHW
24 model
kW
28 model
kW
33 model
kW
40 model
kW
Max Gas Rate
24 model
28 model
33 model
40 model
NOx Class
Inlet Pressure (Natural Gas - G20)
mbar
20
Max
Max
24
28
33
40
(Natural Gas - G20)
(After 10 mins)
m3/h
2.61
m3/h
3.1
3.6
m3/h
m3/h
4.36
Product Characteristic Database
(SEDBUK)
SAP 2009 Annual Efficiency
24 & 28 - 88.6 %
33 & 40 - 88.5%
This value is used in the UK Government’s Standard
Assessment Procedure (SAP) for energy rating of
dwellings. The test data from which it has been
calculated has been certified by 0085.
NOTE: All data in this section are nominal values
and subject to normal production tolerances.
bar
3
2.5
0.5
1-2
Safety Discharge
Max Operating
Min Operating
Recommended Operating Range
Electrical Supply
230V~ 50Hz
(Appliance must be connected to an
earthed supply)
DHW Circuit
Pressures
Max Operating
Min Operating
Power Consumption
24 - 85W
28 - 120W
33 & 40 - 125W
bar
8
0.15
Flow Rates
(24) (28) (33)
l/min l/min l/min
(40)
l/min
DHW Flow Rate
@ 30o C Rise
11.43 13.3
15.7
19.1
DHW Flow Rate
@ 35o C Rise
9.8
11.5
13.5
16.4
Condensate Drain
To accept 21.5mm (3/4 in) plastic waste pipe
Min Working
DHW Flow Rate
2
2
2
2
Flue Terminal
Dimensions
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.
Electrical Protection
IPX0D (with timer)
IPX5D (without timer)
External Fuse Rating
Min
7.4
9.5
10.2
12.1
5
Central Heating Primary Circuit
Pressures
Injector (Natural Gas - G20)
7.5mm (24 & 28) 12mm (33 & 40)
Heat Input CH Qn Hs (Gross)
Max
22.7
27.4
32.1
36.4
Titanium 24, 28, 33 & 40 Combi ErP
3A
Internal Fuse Rating
F2L
Diameter
Projection
Connections
Gas Supply
Central Heating Flow
Central Heating Return
Cold Water Mains Inlet
DHW Flow
Pressure Relief Discharge
Outercase Dimensions
Casing Height
Overall Height Inc Flue Elbow
Casing Width
Casing Depth
Clearances
Above Casing
Below Casing
Front
Front
L.H. Side
R.H. Side
-
100mm
125mm
copper tails
22mm
22mm
22mm
15mm
15mm
15mm
-
Pump
Available Head
Expansion Vessel
- (For Central Heating only.
Integral with appliance)
bar
Min Pre-charge Pressure
0.5
780mm
940mm
450mm
345mm
(24 & 28) (33 & 40)
litre
litre
Max Capacity of
CH System
Primary Water Content
of Boiler (unpressurised)
Weights (kg)
Packaged Boiler Carton
Installation Lift Weight
125
2.5
2.8
Temperatures
C.H. Flow Temp (adjustable)
25°C to 80°C max (± 5°C)
*This is MINIMUM recommended dimension. Greater
clearance will aid installation and maintenance.
Packaged Boiler Carton
Installation Lift Weight
125
For greater system capacities an additional
expansion vessel MUST be fitted.
175 mm Min
150 mm Min*
450 mm Min (For Servicing)
5 mm Min (In Operation)
5 mm Min
5 mm Min (In Operation)
Packaged Boiler Carton
Installation Lift Weight
See graph below
D.H.W. Flow Temp (adjustable)
35°C to 60°C max (± 5°C)
dependent upon flow rate
(24 & 28 model)
46.0
40.2
(33 model)
47.5
41.7
(40 model)
48.0
42.2
Pump - Available Head
5.5
5
4.5
4
3.5
Metre (wg)
3
2.5
2
1.5
1
0.5
0
0
10
© Baxi Heating UK Ltd 2016
200
400
600
Flow Rate (l/h)
800
1000
1200
4.0 Technical Data
4.2
Technical Parameters
Technical parameters for boiler combination heaters
Potterton Titanium Combi ErP
24
28
33
40
Condensing boiler
Yes
Yes
Yes
Yes
Low-temperature boiler(1)
No
No
No
No
B1 boiler
No
No
No
No
Cogeneration space heater
No
No
No
No
Combination heater
Yes
Yes
Yes
Yes
Prated
kW
20
24
28
32
Useful heat output at rated heat output
and high temperature regime(2)
P4
kW
20.0
24.0
28.0
32.0
Useful heat output at 30% of rated heat
output and low temperature regime(1)
P1
kW
6.6
7.9
9.2
10.6
Seasonal space heating energy efficiency Šs
%
92
92
92
92
Useful efficiency at rated heat output and Š4
high temperature regime(2)
%
87.9
87.9
87.9
87.8
Š1
%
96.8
96.8
96.7
96.7
Full load
elmax
kW
0.034
0.042
0.043
0.049
Part load
elmin
kW
0.016
0.016
0.017
0.018
Standby mode
PSB
kW
0.003
0.003
0.003
0.003
Standby heat loss
Pstby
kW
0.040
0.040
0.040
0.040
Ignition burner power consumption
Pign
kW
-
-
-
-
Annual energy consumption
QHE
kWh
GJ
17391
63
20870
75
24348
88
27826
100
Sound power level, indoors
LWA
dB
50
53
52
50
Emissions of nitrogen oxides
NOX
mg/kWh
20
23
20
23
XL
XL
XL
XL
Daily electricity consumption
Qelec
kWh
0.186
0.188
0.184
0.197
Annual electricity consumption
AEC
kWh
41
41
40
43
Water heating energy efficiency
Šwh
%
84
81
83
84
Daily fuel consumption
Qfuel
kWh
23.220
24.307
23.695
23.102
Annual fuel consumption
AFC
GJ
18
18
18
18
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
NOTE: There must be no part of the air duct (white
tube) visible outside the property after installation. The
flue seal should fit neatly and effect a good seal. For full
detail refer to Section 9.7 “Fitting the Flue”.
5.0 Dimensions and Fixings
Dimensions
A 780mm
B 345mm
At Least 1.5°
E
G
C 450mm
D 116mm Ø Min.
E 160mm
(207mm for 80/125mm
flue systems)
A
F 145mm
G 131mm
H 180mm
B
360° Orientation
H
D
C
Tube Ø 100mm
Tap Rail
F
32.5 mm
Condensate
Drain
65 mm
Heating
Flow
(22mm)
12
© Baxi Heating UK Ltd 2016
65 mm
Domestic Hot
Water Outlet
(15mm)
65 mm
Gas
Inlet
(22mm)
65 mm
Cold Water
Inlet
(15mm)
65 mm
Heating
Return
(22mm)
Pressure Relief
Valve
(15mm)
6.0 System Details
6.1
Information
1. The Potterton Titanium Combi ErP is a ‘Water Byelaws
Scheme - Approved Product’.
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
Central Heating Circuit
1. The appliance is suitable for fully pumped SEALED SYSTEMS
ONLY.
Treatment of Water Circulating Systems
• All recirculatory water systems will be subject to corrosion
unless an appropriate water treatment is applied. This means
that the efficiency of the system will deteriorate as corrosion
sludge accumulates within the system, risking damage to
pump and valves, boiler noise and circulation problems.
• When fitting new systems flux will be evident within the
system, which can lead to damage of system components.
• BS7593 gives extensive recommendations on system
cleansing and water treatment.
• All systems must be thoroughly drained and flushed out
using an appropriate proprietary flushing agent.
• A suitable inhibitor must then be added to the system.
• All system additives (flushing agents, cleansers, inhibitors
etc.) must comply with the requirements of BS7593. Full
instructions are supplied with the products and for further
information contact the additive manufacturer directly or
consult their website.
Failure to flush and add inhibitor to the system will
invalidate the appliance warranty.
• It is important to check the inhibitor concentration after
installation, system modification and at every service in
accordance with the inhibitor manufacturer. (Test kits are
available from inhibitor stockists.)
• For information or advice regarding any of the above
contact Baxi Customer Support 0344 871 1545.
6.3
Bypass
1. The boiler utilises the primary side of the DHW plate heat
exchanger as an automatic integral bypass.
6.4
System Control
1. The boiler is designed for use in a heating system that
incorporates external controls, i.e. a minimum of a timer
device.
2. Suitable timer kits are available as optional extras.
3. For optimum operating conditions and maximum economy
the fitting of a programmable room thermostat is
recommended.
© Baxi Heating UK Ltd 2016
13
6.0 System Details
6.5
Stop
Valve
Double
Check
Valve
System Filling and Pressurising (Fig. 4)
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
A filling loop & instructions are provided with the boiler.
DHW
Mains
Inlet
Temporary
Hose
CH
Return
2. The filling method adopted must be in accordance with all
relevant water supply regulations and use approved
equipment.
Fig. 4
3. 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”.
4. 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.
Filling Loop
Connections
IMPORTANT: If the boiler is installed at a high point in
the system it is strongly recommended that Automatic Air
Vent Kit 720004701 is fitted.
Fig. 5
6.6
Expansion Vessel (Central Heating only)
1. The appliance expansion vessel is pre-charged to 0.5 bar.
Therefore, the minimum cold fill pressure is 0.5 bar. The
vessel is suitable for correct operation for system capacities up
to 125 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.
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. The end of the
pipe should terminate facing down and towards the wall.
Fig. 6
Pressure Relief Valve
Discharge Pipe
14
© Baxi Heating UK Ltd 2016
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).
6.0 System Details
6.8
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
Domestic Hot Water Circuit (Fig. 7)
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. Also if there is an existing check valve, loose jumpered
stop cock, water meter or water treatment device already
fitted to the wholesome water supply connected to the
boiler domestic hot water (DHW) inlet supply then a
suitable expansion device may be required.
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
7.0 Site Requirements
450mm
5mm Min
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. If the boiler is sited in an unheated enclosure then it is
recommended to leave the ON/OFF Selector Switch in the
domestic hot water and central heating position to give frost
protection.
780mm
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.
150mm Min*
Fig. 8
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).
*This is the MINIMUM recommended dimension. Greater
clearance will aid installation and maintenance.
At Least 1.5°
7.2
Clearances (Figs. 8 & 9)
1. A flat vertical area is required for the installation of the
boiler.
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.
450mm Min
For Servicing
Purposes
5mm Min
In Operation
Fig. 9
16
© Baxi Heating UK Ltd 2016
7.0 Site Requirement
Gas Service Cock
7.3
Ventilation of Compartments
1. Where the appliance is installed in a cupboard or
compartment, no air vents are required.
2. BS 5440: Part 2 refers to room sealed appliances installed in
compartments. The appliance will run sufficiently cool without
ventilation.
7.4
Gas Supply
1. The gas installation should be in accordance with the
relevant standards. In GB this is BS 6891. In IE this is the
current edition of I.S. 813 “Domestic Gas Installations”.
Fig. 10
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. Do not use pipes of a smaller diameter than
the boiler gas connection (22mm).
Zone 2
7.5
Window
Recess
Electrical Supply
Zone 2
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.
0.6 m
2. The mains supply is 230V ~ 50Hz fused at 3A.
Zone 1
Zone 0
Window
Recess
NOTE: The method of connection to the electricity supply
must facilitate complete electrical isolation of the appliance.
Zone 2
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.
Fig. A
In GB Only
7.6
Ceiling
Window Recess
Zone 2
Zone 1
Zone 2
Outside Zones
2.25 m
Zone 0
0.6 m
Fig. B
© Baxi Heating UK Ltd 2016
Bath & Shower Rooms
1. Boilers fitted with optional plug-in integral timer, RF receiver
or thermostat CANNOT be fitted in any zone.
2. If the boiler is fitted in a room containing a bath or shower
and NOT FITTED with any optional plug-in integral timer, RF
receiver or thermostat, 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.
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
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 7.7.15 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.
i) Termination to an internal soil and
vent pipe
50mm
per me
2.5° M
tre of
inimum
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.
pipe ru
n
fall
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.
450mm min*
*450mm is applicable to
properties up to 3 storeys.
For multi-storey building
installations consult BS 6798.
ii) External termination via internal discharge branch
e.g sink waste - downstream*
Boiler
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.
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.
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.
Sink
50mm
per me
2.5° M
tre of
inimum
fall
pipe ru
n
Pipe must terminate above
water level but below
surrounding surface. Cut
end at 45°
8. External runs MUST be a MINIMUM of 32mm and fully
insulated with material suitable for external use.
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.
*It is NOT RECOMMENDED
to connect upstream of the
sink or other waste water
receptacle !
18
© Baxi Heating UK Ltd 2016
7.0 Site Requirements
7.7
iii) Termination to a drain or gully
Boiler
Pipe must terminate above
water level but below
surrounding surface. Cut
end at 45°
50mm
per me
tre of
2.5° M
inimum
Condensate Drain (cont.)
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.
pipe ru
n
fall
iv) Termination to a purpose made soakaway
Further specific requirements for soakaway
design are referred to in BS 6798.
Boiler
500mm min
50mm p
er metr
e of pip
2.5° Min
e run
imum fa
ll
Holes in the soak-away must
face away from the building
© Baxi Heating UK Ltd 2016
19
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
20
© Baxi Heating UK Ltd 2016
pipe ru
n
fall
Pipe must terminate above
water level but below
surrounding surface. Cut
end at 45°
Terminal Position with Minimum Distance (Fig. 18)
(mm)
7.0 Site Requirements
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
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.
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.
1 In addition, the terminal should be no nearer than 150 mm to an opening in the
building fabric formed for the purpose of accommodating a built-in element such as
a window frame.
2 Only ONE 25mm clearance is allowed per installation. If one of the dimensions
4. * Reduction to the boundary is possible down to 25mm but
the flue deflector kit (part no. 5111068) must be fitted.
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
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.
*
IMPORTANT: If fitting a Plume
Displacement Flue Kit, the air inlet
must be a minimum of 150mm from
any opening windows or doors.
Plume
Displacement Kit
Top View Rear Flue
Fig. 17
Property Boundary Line
T
Air Inlet
J,K
U
Opening Window
or Door
150mm
MIN.
Fig. 18a
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
© Baxi Heating UK Ltd 2016
Fig. 18
21
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
Twin Flue Pipe
135° bend
0.25 metres
91.5° bend
0.50 metres
Horizontal
Flues
4. The elbow connected to the boiler adaptor is not included
in any equivalent length calculations.
Plume Displacement Kit 60 /100 Ø
5. The illustrations opposite show examples of permissible
flue systems.
1M Extensions, 45° & 93° bends are
also available - see Section 9.0
NOTE: Flue length is measured from point X to Y as
shown.
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.
This bend is equivalent to
1 metre
6. Read this section in conjunction with the Flue Installation
Guide supplied with the boiler.
C
A
(ii)
B
(i)
This bend is equivalent to
1 metre
Total equivalent length =
A+B+C+2x90°Bends
22
© Baxi Heating UK Ltd 2016
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.
8.0 Flue Options
m
5m
68
8.2
mm
0
10
Flue Deflector
Flue Lengths
The standard flue kit allows for lengths between 100mm to
685mm from elbow to terminal (Fig. 19).
Extensions of 250mm, 500mm & 1m are available.
The maximum permissible equivalent flue length is:
10 metres (60/100 system - vertical & horizontal)
20 metres (80/125 system - vertical & horizontal)
15 metres (80/80 twin pipe)
Fig. 19
8.3
Fig. 20
Ensure that no part of the white outer
chimney duct is visible
Flue Trim
1. The flexible flue trims supplied can be fitted on the outer
and inner faces of the wall of installation.
8.4
Terminal Guard (Fig. 21)
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).
2. There must be a clearance of at least 50mm between any
part of the terminal and the guard.
3. When ordering a terminal guard, quote the appliance name
and model number.
4. The flue terminal guard should be positioned centrally over
the terminal and fixed as illustrated.
8.5
Fig. 21
Flue Deflector (Fig. 20)
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 (Fig. 22)
United Kingdom
en
1. For full details of Flue Accessories (elbows, extensions,
clamps etc.) refer to the Flue Installation Guide supplied in the
literature pack.
Multifit
These Guidance Notes cover the following boiler models:
Baxi
EcoBlue Combi & System ErP
Duo-tec Combi ErP
Platinum Combi ErP
Megaflo System ErP
Potterton
Promax Combi & System ErP
Gold Combi & System ErP
Titanium Combi ErP
Promax Ultra Combi ErP
Main
Eco Elite Combi & System ErP
Guidance Notes
Flue Accessories Fitting Guide
Ø 60/100 Flue Systems
Ø 80/125 Flue Systems
Ø 80/80 Twin Pipe Systems
Plume Displacement Kit (Ø 60/100 Flue Systems)
READ THESE INSTRUCTIONS IN CONJUNCTION WITH THE BOILER
INSTALLATION MANUAL BEFORE FITTING THE FLUE
IMPORTANT NOTE: This document will assist in the correct installation of the various flue & chimney systems
described within. However, it is the responsibility of the installer/Gas Safe registered commissioning engineer to
ensure that the flue & chimney system is fitted safely and in compliance with the relevant standards and practices
in force in the country of installation.
Please leave these instructions with the Installation and Service Manual
© Baxi Heating UK Ltd 2016
Fig. 22
23
1.0 Installation
Introduction
9.0
9.1
Unpacking & Initial Preparation
The gas supply, gas type and pressure must be checked for
suitability before connection (see Section 7.4).
NOTE: a small amount of water may drain from the
boiler in the upright position.
1. See section ‘Safe Manual Handling’ before unpacking or
lifting the boiler.
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.
SNAP OFF
LIFT HERE
BOTH SIDES
Fig. 23
2. Follow the procedure on the carton to unpack the boiler
or see Fig. 23.
Pre-plumbing
3. If pre-plumbing (Fig. 24) - the wall jig and fitting kit can be
removed without removing the carton sleeve. Simply slide
banding to the edge and open the perforated flap, lift out
the jig, fitting kit and instructions. If the boiler is to be
installed at a later date, close the flap and reposition the
banding straps, the boiler can now be stored safely away.
To remove only the wall jig slide
banding to the edge and open flaps.
4. After considering the site requirements
(see Section 7.0) position the fixing template on the wall
ensuring it is level both horizontally and vertically.
Slide the wall jig out of carton then
close the flaps. Slide banding back on.
5. Mark the position of the two most suitable fixing slots for
the wall plate and boiler lower fixing holes. It is preferable to
use the vertical fixing slots.
Fig. 24
6. Mark the position of the centre of the flue hole (rear
exit). For side flue exit, mark as shown (Fig. 25).
145mm
7. If required, mark the position of the gas and water pipes.
Remove the template.
8. Cut the hole for the flue (minimum diameter 116mm).
40 model only
9. Drill the wall as previously marked to accept the wall
plugs supplied. Secure the wall plate using the fixing screws.
For Side Flue Exit
Fig. 25
Fig. 27
Flushing Tube
Flow Regulator
Wall Plate
10. Using a spirit level ensure that the plate is level before
finally tightening the screws.
11. Connect the gas and water pipes to the valves on the
wall plate using the copper tails supplied. Ensure that the
sealing washers are fitted between the connections.
IMPORTANT: ONLY on 40 models the Cold Water
Inlet tap is fitted with a flow regulator. The copper tail is
factory fitted on this model, but must be loosened and
turned through 180° to point downwards. Ensure the
joint is fully tight (Fig. 27).
Central Heating Return
Fig. 26
12. Fit the filling loop as described in the instructions
supplied with it.
9.2
Flushing
1. Connect a tube to the central heating flow or return pipe
(Fig. 26).
24
© Baxi Heating UK Ltd 2015
2. Flush thoroughly (see System Details, Section 6.2).
9.0 Installation
9.3
Note: Full instructions are provided in
the Filling Loop Kit pack.
Fitting the Filling Loop Kit
1. The filling loop kit supplied with the boiler can be
connected to the taps on the wall plate at this point.
(Either one of two types of loop kit will be supplied both function in the same way, differing only in detail).
2. The filling loop is to be connected between the mains
cold water inlet and central heating return isolation taps.
3. The loop and valves must be connected as described
in the instructions supplied with it.
4. Note the orientation of the flow direction arrows on
the stop valve and double check/stop valves.
Fig. 28
Cold Inlet
5. Remove the blanking caps from the mains cold water
inlet and central heating return isolation taps (Fig. 28).
Connect the valves to the taps, ensuring that the fibre
washers supplied are used on these joints.
6. Connect the temporary loop, ensuring that the seals
are fitted.
To fill, test and flush if required (Fig. 29)
7. Take the blanking plugs from the kit, and using washers
supplied with the boiler, connect them to the central
heating flow and return taps, and the cold inlet tap. The
system can now be filled by opening the cold inlet supply
and stop valves.
Blanking Caps
CH Return
8. If desired a suitable gauge can be connected to one of
the taps so that the system may be accurately
pressurised.
9. All joints, fittings and system components can now be
examined for soundness at operating pressure.
10. The system can be flushed by turning off the central
heating tap and connecting a suitable fitting to the loose
nut. From the fitting a hose pipe can be run to the
nearest convenient drain. When the tap is reopened the
system will flush.
Pressure
Gauge
11. Remove the blanking plug(s), pressure gauge and
flushing equipment from the appliance if used.
Blanking
Plugs
12. Continue with the installation and commissioning.
Hose and
Fitting
13. The filling loop must be disconnected and completely
removed after the system is pressurised.
Fig. 29
© Baxi Heating UK Ltd 2016
14. Depending upon the type of kit supplied either hand
tighten the two previously removed blanking caps to the
stop valve and double check valve, or use the caps
supplied in the kit.
25
9.0 Installation
Wall Plate
9.4
Fitting The Boiler (Fig. 30)
1. Remove the sealing caps from the boiler connections.
Remove Sealing Caps from
under the Boiler after lifting
into position
NOTE: A small amount of water may drain from the boiler
once the caps are removed.
Sealing
Washers
2. Lift the boiler as indicated by the shaded areas and the
bottom polystyrene. The boiler should be lifted by TWO
PEOPLE. Engage the slots at the top rear of the boiler on the
wall plate (see Safe Manual Handling page 5).
3. Insert the sealing washers between the valves and pipes on
the wall plate and the boiler connections.
4. Tighten all the connections.
9.5
Fig. 30
Fitting the Pressure Relief Discharge Pipe
(Fig. 31)
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.
Lift Here
Both Sides
Bottom Polystyrene
When the Boiler Mounting Bracket on the
Boiler is in position on the Retaining Lugs,
the bottom polystyrene may be discarded
allowing the boiler to swing into position
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.
5. Complete the discharge pipework and route it to the
outside discharge point.
IMPORTANT: Make all soldered joints before connecting
to the pressure relief valve.
9.6
Condensate Drain (see section 7.7)
1. Connect the condensate drain to the trap outlet pipe.
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”.
Pressure Relief Valve
2. The connection 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.
Fig. 31
3. The boiler condensate trap should be primed by pouring
approximately 300ml of water into the flue spigot. Do not
allow any water to fall into the air inlet.
Discharge Pipe
Prime Trap by
pouring 300ml of
water into flue spigot
26
© Baxi Heating UK Ltd 2016
9.0 Installation
m
5m
68
9.7
m
0m
10
Fitting The Flue
HORIZONTAL FLUE
1. The standard flue is suitable for lengths between 100mm
minimum and 685mm maximum, as measured from the
edge of the flue elbow outlet to the joint between the
terminal and air duct (Fig. 32).
Fig. 32
2. Locate the flue elbow on the adaptor at the top of the
boiler. Set the elbow to the required orientation (Fig. 33).
NOTE: The flue elbow is angled at 93 degrees to
ensure a fall back to the boiler.
3. Measure the distance from the outside wall face to the
elbow. This dimension will be known as ‘X’ (Fig. 34).
Wall Thickness
4. To dimension ‘X’ add 50mm. This dimension to be
known as ‘Y’.
Flue Elbow
(X)
IMPORTANT: Check all dimensions before cutting.
Apply Lubricant for
ease of assembly.
Ensure Elbow is fully
engaged into Boiler
Adaptor
Adaptor
5. Mark dimension ‘Y’ on the flue as shown (Fig. 35).
Carefully cut the waste material from the flue, ensuring that
the ducts are square and free from burrs.
Fig. 33
Wall Thickness
(X)
Fig. 34
Waste
Y
Flue
Fig. 35
© Baxi Heating UK Ltd 2016
27
9.0 Installation
Centralising Collar
9.7
Fitting the Flue (Cont)
6. The centralising collar may be in the waste portion of the
flue. In this case retrieve the collar before discarding the
waste.
7. Take the centralising collar (if not already fitted) and
engage it over the flue duct. This will centralise the flue and
air ducts, and ease assembly (Fig. 36).
Fig. 36
8. Insert the flue through the hole in the wall. Fit the elbow
to the boiler adaptor, ensuring that it is pushed fully in.
Apply Lubricant for
ease of assembly.
Ensure Flue is fully
engaged into Flue
Elbow
9. Draw the flue back through the wall and engage it in the
elbow. It may be necessary to use soap solution or similar
to ease assembly of the elbow adaptor and flue (Fig. 37).
10. Ensure that the terminal is positioned with the slots to
the bottom (Fig. 38). Secure the flue to the elbow with the
screws supplied (Fig. 37).
Flue to elbow
securing screws
11. Secure the elbow flue to the boiler adaptor with the
screws supplied in the boiler fittings pack (Fig. 37).
IMPORTANT: It is essential that the flue terminal is fitted
as shown to ensure correct boiler operation and prevent
water entering the flue.
Elbow to adaptor
securing screws
11. Make good between the wall and air duct outside the
building.
12. Fit the flue trim if required, and if necessary fit a terminal
guard (see Section 8.4).
Fig. 37
Slots at bottom
Fig. 38
28
© Baxi Heating UK Ltd 2016
9.0 Installation
9.8
Making The Electrical Connections
The boiler is fitted with a 1.3m length of 3 core cable. This
can be connected to the fused 3A 230V 50HZ supply.
NOTE: Both the Live and Neutral connections are fused.
To connect an external control proceed as follows:Terminal Block Cover
1. Slacken the facia panel securing screws and lift the
outercase panel so that its securing tabs are clear of the
facia. Remove the panel.
2. Completely undo the screws securing the facia panel and
hinge it down (Fig. 39).
3. Undo the terminal block cover securing screw and
remove the cover (Fig. 39).
Fig. 39
Fig. 40
4. Slacken the unused cable clamp on the LH side of the
boiler chassis (Fig. 40). Insert the external control wiring
through the clamp and route it to the terminal block.
Facia Panel
Cable Clamp
5. Refer to the instructions supplied with the control.
IMPORTANT: The room thermostat MUST be suitable
for 230V switching.
Fused Spur
L
N
Room ‘Stat
NOTE: An external frost thermostat cannot be used in
conjunction with the integral timer. The integral timer can
be replaced with the blanking plate supplied in the
installation kit, and wiring connected as in Fig. 41.
N
bk 1
bk 2
230V
g/y
b
N
br
L
6. 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 (Fig. 41). If the room thermostat
being used incorporates an anticipator it MUST be wired as
shown in Fig. 41.
7. Ensure that the external control input cable(s) have
sufficient slack to allow the control box to drop down.
Tighten the cable clamp on the boiler chassis.
Fig. 41
Frost Thermostat
Fused Spur
L
8. Replace the terminal block cover, routing the external
control input cable(s) through the second cut-out.
N
Room ‘Stat
230V
N
9.9
Preliminary Electrical Checks
bk 1
230V
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
29
10.0 Commissioning
10.1
Commissioning the Boiler
1. Reference should be made to BS:EN 12828 & 14336 when
commissioning the boiler.
2. At the time of commissioning, complete all relevant sections
of the Benchmark Checklist at the rear of this publications.
3. Open the mains water supply to the boiler.
Screw
4. Open all hot water taps to purge the DHW system.
5. Ensure that the filling loop is connected and open, then open
the heating flow and return valves on the boiler.
Pump
Automatic Air
Vent
6. Open the screw on the automatic air vent on the pump body
(Fig. 42).
IMPORTANT: If the boiler is installed at a high point in the
system it is strongly recommended that Automatic Air Vent
Kit 720004701 is fitted. Ensure that this vent is open.
7. The system must be flushed in accordance with BS 7593 (see
Section 6.2) and the flushing agent manufacturers instructions.
8. Pressurise the system to 1.5 bar (Fig. 43) then close and
disconnect the filling loop.
Pump
Fig. 42
9. Turn the gas supply on and purge according to in GB BS 6891
and in IE I.S. 813 “Domestic Gas Installations”.
2
1
3
10. Test for gas tightness.
4
0
bar
11. Hinge the facia panel upwards and refit the case front panel.
Tighten the securing screws.
Selector Switch
Display
Pressure Gauge
Fig. 43
2
1
12
11
3
7
10
9
0
4
1
12
11
Domestic Hot Water
Temperature Control
2
Central Heating
Temperature Control
3
bar
5
4
0
AM
8
3
7
1
8
PM
9
5
10
4
2
Reset
12. 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:
13. The Combustion Check procedure as shown by the chart
in 10.2 is mandatory. The method of setting the boiler to
operate at maximum and minimum rates to comply with the
procedure is described below.
14. Ensure that all external controls are calling for heat. The
actual current boiler temperature is shown on the display.
15. Turn both control knobs fully anticlockwise, then quickly turn
the right hand knob 1/4 clockwise twice and back fully
anticlockwise.
16. The display (Fig. 44) will now alternate between ‘SF’ and the
current boiler temperature and both green LEDs will flash.
Fig. 44
17. To set to maximum rate.
Turn the left hand knob fully clockwise. As the knob is turned
the display will change, indicating the fan speed.
18. The display will show ‘00’, indicating maximum rate, then
revert to ‘P ‘ alternating with the current boiler temperature.
19. To set to minimum rate.
Turn the left hand knob fully anti-clockwise. As the knob is
turned the display will change, indicating the fan speed. When
the display reads ‘ 0’ the boiler runs at minimum rate.
30
© Baxi Heating UK Ltd 2016
20. This function is maintained for 20 minutes unless the
maximum CH temperature is exceeded. The function can be
disabled at any time by turning the right hand knob.
Set Boiler to Maximum Rate
(see 10.1.13)
Allow the combustion to
stabilise. Do not insert probe to
avoid ‘flooding’ the analyser.
10.0 Commissioning
10.2
Checking Combustion
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
(see 10.1.19)
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.
31
x2
10.0 Commissioning
10.3
Central Heating
Temperature Control
Fig. 45
Check the Operational (Working) Gas Inlet
Pressure
1. Ensure that all controls are calling for heat, and the selector
switch is in the central heating and hot water position (
).
The current boiler temperature is shown on the display.
Domestic Hot Water
Temperature Control
2. It is necessary to set the boiler to ‘Calibration Mode’.
Selector Switch
Display
2
1
12
11
3
7
3
10
9
0
4
2
1
12
11
Central Heating
Temperature Control
3
bar
5
4
0
3. Turn both temperature control knobs fully anticlockwise,
then quickly turn the DHW temperature knob 1/4 clockwise
twice and back fully anticlockwise (Fig. 45).
AM
8
7
1
8
PM
9
5
2
Reset
10
4
4. The display will now alternate between ‘SF’ and the current
boiler temperature and both green LEDs will flash (Figs. 47 &
48).
Domestic Hot Water
Temperature Control
5. Turn CH temperature control knob fully clockwise. As the
knob is turned the display will change from ‘0’ to ‘00’ (Fig. 49)
indicating maximum rate, then revert to ‘P’ alternating with the
current boiler temperature (Figs 50 & 51).
Gas Valve
Gas Pressure
Test Point
6. With the boiler operating in the maximum rate condition
check that the operational (working) gas pressure at the inlet
gas pressure test point (Fig. 46) is in accordance with B.S. 6798
& B.S. 6891.
Fig. 46
7. Ensure that this inlet pressure can be obtained with all other
gas appliances in the property working.
Measure the Gas Rate
8. With any other appliances & pilot lights turned OFF the gas
rate can be measured. It should be between:-
Fig. 47
Fig. 48
Fig. 49
24 model
2.61m3/h
28 model
3.1m3/h
33 model
3.6 m3/h
40 model
4.36 m3/h
9. The ‘Calibration Function’ is active for 20 minutes unless the
maximum CH temperature is exceeded.
10. The function can be disabled at any time by turning the
DHW temperature knob.
P. OUT
Gas Valve
RQ
ADJ.
Fig. 51
VENT
Fig. 50
EV2
1
17-21 mbar
2
3
EV1
4
Gas Cock
19-23 mbar
Gas Meter
Fig. 51a
32
© Baxi Heating UK Ltd 2016
11. 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.
12. 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.
13. Working Gas Pressures
If the pressure drops are greater than shown in Fig. 51a a
problem with the pipework or connections is indicated.
Permissible pressure drop across system pipework 1 mbar.
10.0 Commissioning
10.4
Setting the Timer
10
NOTE: If the integral timer is not required fit the blanking
plate supplied in the installation kit.
9
Time Pointer
The Electro-Mechanical Timer allows the central heating
system to be set every 15 minutes.
8
Constant
7
Using the three position switch the timer will allow either
constant operation, timed operation or central heating off.
Timed
Move the switch button by sliding to the desired position.
AM
Off
Three position switch (Fig. 52)
5
0
4
IN
3
Fig. 52
2
Rotate to adjust time
Constant (Top position): The heating will be on
constantly irrespective of the position of the tappets.The
heating will be controlled by the main thermostat on the
appliance and/or any external controls.
Timed (Central position): The heating will operate
according to the position of the tappets and be controlled as
above.
4
2
1
12
3
0
Off (Bottom position): No central heating.
Domestic hot water will operate on demand.
11
To set the time of day
Turn the timer outer bezel clockwise, to align the pointer
with the correct time to the nearest 15 minutes
ensuring that A.M./P.M. is considered. Do not at any time
attempt to turn the bezel anti-clockwise.
AM
8
7
7
8
PM
9
5
10
4
4
9
10
5
0
GRASSLIN
To set the timed heating program
Decide which times of the day the central heating is required.
3
2
1
12
11
The heating will operate when the white tappets are set to
the outer edge of the bezel.
To ensure the heating stays OFF set the required tappets
inwards towards the centre of the bezel.
Each tappet represents 15 minutes.
For example: If the heating is not required between
10 A.M. and 11 A.M. the four tappets anticlockwise from the
10 A.M. will be set inwards (Fig. 53).
On Position
12
Off Position
11
10
9
Time Pointer
© Baxi Heating UK Ltd 2016
Fig. 53
33
11.0 Completion
11.1
Case Front Panel
Completion
1. Instruct the user in the operation of the boiler and
system explaining the operational sequence.
2. Set the central heating and hot water temperature
control knobs to the requirements of the user.
3. Carefully read and complete all sections of the
Benchmark Commissioning Checklist at the rear of this
publication that are relevant to the appliance 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.
4. For IE, it is necessary to complete a “Declaration of
Conformity” to indicate compliance with I.S. 813. An
example of this is given in I.S. 813 “Domestic Gas
Installations”. This is in addition to the Benchmark
Commissioning Checklist.
5. Hand over the Users Operating, Installation and
Servicing Instructions giving advice on the necessity of
regular servicing.
Facia Panel
Fig. 54
34
© Baxi Heating UK Ltd 2016
12.0 Servicing
12 .1
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.
Case Front Panel
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.
• 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 10.3.8.
• 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:-
Fig. 55
Facia Panel Securing
Screws
• 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.
• 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.
6. If the combustion reading (CO/CO2 ratio) is greater than
this, and the integrity of the complete flue system and
combustion circuit seals has been verified, and the inlet gas
pressure and gas rate are satisfactory either:
• Perform the ‘Annual Servicing - Inspection’ (Section 12.2) &
re-check
• Adjust the gas valve (Section 14.0) & re-check
• Replace the gas valve (Section 13.24) & re-check
12.2
Inner Door
Panel
Fig. 56
Annual Servicing - Inspection
1. Ensure that the boiler is cool.
2. Ensure that both the gas and electrical supplies to the
boiler are isolated.
3. Slacken the screws securing the facia panel. Lift the outercase
panel so that its securing tabs are clear of the facia. Remove the
panel, allowing the facia to hinge down (Fig. 55).
4. Remove the screws securing the inner door panel. Lift the
panel slightly to disengage it from the studs on top of the case
(Fig. 56).
Sump
5. Unscrew the sump from the bottom of the condensate trap
assembly (Fig. 57) and remove any deposits from the sump and
trap. Clean as necessary and replace the sump.
Fig. 57
© Baxi Heating UK Ltd 2016
35
4 ±0.5
Burner
12.0 Servicing
12.2
Viewing Window
Annual Servicing - Inspection (Cont)
6. Undo the nut on the gas inlet pipe to the venturi (Fig. 60)
and pull the sensing pipe off the fan.
7. Disconnect the electrode leads, noting their position, and
the fan electrical plugs.
Sensing
Electrode
7.5
±1
Spark Ignition
Electrode
10 ±1
Fig. 58
8. Undo the four nuts retaining the combustion box cover
to the heat exchanger. Disconnect the sensing pipe and
wires from the air pressure switch.
9. Carefully draw the fan, collector, air pressure switch and
cover assembly forward, being careful to retain the injector
in the venturi (Figs. 59 & 60).
Electrode Position
Fan, Collector and Cover
Assembly
10. Clean any debris from the heat exchanger and check
that the gaps between the tubes are clear.
11. Inspect the burner, electrodes (Fig. 58) and insulation,
cleaning or replacing if necessary. Clean any dirt or dust
from the air box.
12. Reassemble in reverse order.
NOTE: The sensing pipe must be reconnected to the
fan, not the venturi.
Electrode
Leads
DHW Filter (Fig. 62)
13. If the flow of domestic hot water is diminished, it may
be necessary to clean the filter.
Fig. 59
14. Initially check the cold water inlet tap filter.
Venturi
15. Turn the tap off and draw off from a hot tap. Undo the
blanking cap and remove the threaded bush (Fig. 61).
Injector
Threaded
Fig. 61
16. Extract the filter and rinse thoroughly in clean water.
Reassemble and check the flow. If required clean the
restricter filter as described below.
Bush
17. Pull off the Hall Effect sensor. Undo the restricter from
the inlet/return manifold (Fig. 62).
Fig. 60
Gas Inlet Pipe
18. Rinse the filter thoroughly in clean water and reassemble
in reverse order.
Hall Effect
Sensor
Blanking
Cap
Restricter
Filter
Hydraulic Inlet
Assembly
Fig. 62
36
© Baxi Heating UK Ltd 2016
Cold Water
Inlet Tap
19. Turn the selector switch fully anticlockwise against the
spring pressure to the reset position and hold for 5 seconds
to reset the boiler.
20. 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.
Bracket
13.0 Changing Components
Igniter
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 turn the selector switch
fully anticlockwise against the spring pressure to the
reset position and hold for 5 seconds to reset the boiler
before recommissioning.
Igniter Feed
Plug
Electrode
Leads
Fig. 63
See Section 12.1 “Annual Servicing” for removal of case
panel, door etc.
13.1
Spark
Electrode
Igniter (Fig. 63)
1. Disconnect the igniter feed plug and the electrode leads,
noting their positions.
2. Undo the screw securing the bracket to the boiler.
3. Remove the igniter and transfer the bracket to the new
component.
4. Reassemble in reverse order.
Electrode
Leads
Sensing
Electrode
13.2
Spark and Sensing Electrodes (Fig. 64)
Fig. 64
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.
3. Check the condition of the sealing gasket and replace if
necessary. Reassemble in reverse order.
Air Pressure
Switch
(Vertical
Mounting)
13.3
Air Pressure Switch (Fig. 64a)
Depending on model the switch can be mounted vertically
or horizontally.
VERTICAL MOUNTING
1. Slacken the screw securing the Air Pressure Switch
bracket to the collector, and remove the screws holding the
switch to the bracket.
Bracket
Sensing
Pipe
2. Ease the sensing pipe off the P1 spigot on the switch and
disconnect the two wires.
Fig. 64a
3. Reassemble in reverse order.
3
2
1
Bracket
Connect to terminals
1 & 2 (3 not used)
Sensing
Pipe
HORIZONTAL MOUNTING
1. Undo the screw securing bracket to the side panel.
Remove the screws holding the Air Pressure Switch to the
bracket.
Air Pressure
Switch
(Horizontal
Mounting)
2. Ease the sensing pipe off the P1 spigot on the switch and
disconnect the two wires.
3. Reassemble in reverse order.
© Baxi Heating UK Ltd 2016
37
13.0 Changing Components
13.4
Fan (Fig. 66)
1. Undo the nut on the gas inlet pipe to the venturi (Fig. 66)
and pull the sensing pipe off the fan.
2. Disconnect the electrode leads, noting their position and
disconnect the fan electrical plugs. Disconnect the sensing
pipe and wires from the air pressure switch (not 40 models).
3. Undo the screws securing the collector to the cover (33 &
40 models) or extension piece (24 & 28 models).
4. Remove the collector, air pressure switch and fan
assembly, being careful to retain the injector in the venturi.
5. Undo the screws securing the fan to the venturi and fit the
new fan, replacing the seal if necessary.
6. Examine the burner gasket and replace if necessary.
Venturi
7. Reassemble in reverse order, ensuring that the injector is
in place and the sensing pipe is connected to the fan.
Injector
13.5
Venturi (Fig. 65)
Cover
1. Remove the collector and fan assembly as described in
section 13.4.
2. Extract the injector from the venturi.
Gas Inlet Pipe
Fig. 66
3. Undo the screws securing the fan to the venturi and the
venturi to the collector.
Burner
Gasket
Important: When fitting the new venturi, ensure the arrows
on it’s base point into the collector (Fig. 67).
4. Examine the seals and burner gasket, replace if necessary.
Gas Inlet
Fan
5. Reassemble in reverse order, ensuring that the injector is
in place.
13.6
Venturi
Injector
Injector (Fig. 65)
1. Remove the collector and fan assembly as described in
section 13.4.
Collector
Fig. 65
2. Extract and replace the injector and reassemble in reverse
order.
Fig. 67
When fitting the venturi
ensure that the arrow is
pointing forward
38
© Baxi Heating UK Ltd 2016
13.0 Changing Components
Cover
13.7
Burner (Fig. 68)
Burner
1. Undo the screws securing the collector to the venturi and
extension piece. Allow the air pressure switch to rest on
the air box lower panel. Remove the extension piece from
the cover (on 24 and 28 models).
Gasket
Extension Piece
(where fitted)
2. Withdraw the burner from the cover and replace with
the new one.
3. Examine the gasket, replacing if necessary.
Venturi
4. Reassemble in reverse order.
13.8
Insulation (Fig. 69)
Collector
1. Remove the electrode leads, noting their positions. Also
remove the electrodes as described in section 13.2.
Fig. 68
2. Undo the screws securing the collector to the venturi and
the nuts holding the cover to the heat exchanger. Allow the
air pressure switch to rest on the air box lower panel (not
40 models). Draw the collector and cover assembly away.
3. Remove the cover insulation piece.
4. Fit the new insulation carefully over the burner and align
it with the slots for the electrodes.
5. 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
6. DO NOT remove the shrink-wrapped coating from the
replacement rear insulation. Keep the insulation vertical and
press firmly into position.
Rear
Insulation
7. Examine the cover seal and replace if necessary.
Spark
Electrode
Venturi
Cover
Insulation
Seal
Fig. 69
Collector
Electrode
Leads
Sensing
Electrode
© Baxi Heating UK Ltd 2016
39
13.0 Changing Components
Electrical
Plug
13.9
Flue/Heat Exchanger
Thermostat Sensor
Flue/Heat Exchanger Thermostat Sensor
(Fig. 70)
1. Ease the retaining tab on the sensor away and disconnect
the electrical plug.
2. Turn the sensor 90° anticlockwise to remove - it is a
bayonet connection.
3. Reassemble in reverse order.
Fig. 70
13.10
Water Pressure Sensor (Fig. 72)
1. Drain the primary circuit.
2. Disconnect the two wires from the sensor.
3. Undo the nut on the flow pipe securing and sealing the
sensor.
4. Remove the sensor, examine the sealing washer, replacing if
necessary.
5. Reassemble in reverse order. The component is not
polarised - either wire will fit each terminal.
13.11
Flow Pipe
Central Heating
Temperature Sensor
Central Heating Temperature Sensor (NTC)
(Fig. 71)
1. Ease the retaining tab on the sensor away and disconnect
the electrical plug.
2. Unscrew the sensor from it’s pocket and reassemble in
reverse order. The plug will only fit one way.
13.12
Safety Thermostat (Fig. 72)
1. Pull the plug off the thermostat.
Safety Thermostat
2. Remove the screws securing the thermostat to the
mounting plate on the flow pipe.
3. Reassemble in reverse order, ensuring that the plug is
pushed fully on.
Fig. 71
13.13
DHW Temperature Sensor (NTC) (Fig. 72)
1. Turn off the mains cold water supply tap and draw off the
residual domestic hot water.
Pressure Sensor
Plate Heat
Exchanger
2. Ease the retaining tab on the sensor away and disconnect
the electrical plug.
3. Unscrew the sensor from the plate heat exchanger
manifold. Examine the sealing washer,replacing if necessary.
Fig. 72
40
© Baxi Heating UK Ltd 2016
DHW Temperature
Sensor
4. Reassemble in reverse order. The plug will only fit one way.
13.0 Changing Components
13.14
Pump - Complete (Figs. 73 & 74)
1. Drain the boiler primary circuit and disconnect the
electrical plug from the pump motor.
2. Undo the two screws securing the body to the pipe and
manifold and draw the pump forwards.
3. Examine the ‘O’ ring seals on the return pipe and
manifold, replacing if necessary.
4. Reassemble in reverse order.
13.15
Automatic Air Vent - Grundfos (Fig. 73)
1. Drain the boiler primary circuit and unscrew the
automatic air vent from the pump body.
2. Examine the ‘O’ ring seal, replacing if necessary, and fit it
to the new automatic air vent.
3. Reassemble in reverse order.
13.16
Automatic Air
Vent
Automatic Air
Vent
Automatic Air Vent - Wilo (Fig. 74)
1. Drain the boiler primary circuit and remove the ‘U’ clip
securing the automatic air vent to the pump body.
2. Pull the vent upwards away from the body.
3. Examine the ‘O’ ring seal, replacing if necessary, and fit it
to the new automatic air vent.
4. Reassemble in reverse order.
‘U’ Clip
Fig. 73
Grundfos Pump
© Baxi Heating UK Ltd 2016
Fig. 74
Wilo Pump
41
13.0 Changing Components
13.17
Gauge Retaining
Bracket
Pressure Gauge (Figs. 75 & 76)
1. Drain the boiler primary circuit and undo the nut on the
pressure gauge capillary.
2. Undo the screws securing the gauge retaining bracket.
Pressure Gauge
Fig. 75
3. Remove the bracket and gauge assembly. Depress the
barbs on the side of the gauge and remove the retaining
bracket.
4. Examine the sealing washer, replace if necessary.
5. Reassemble in reverse order.
13.18
Hall Effect Sensor (Fig. 77)
1. Ease the sensor upwards off the hydraulic inlet manifold
assembly.
2. Disconnect the electrical plug from the sensor.
Fig. 76
Pressure Gauge
Capillary
Hall Effect
Sensor
3. Connect the plug to the new sensor. Carefully fit the new
sensor to the hydraulic assembly, ensuring it is fully down.
13.19
Pressure Relief Valve (Fig. 78)
1. Drain the boiler primary circuit.
2. Disconnect the discharge pipe from the valve. Using a
suitable hexagon key undo the grub screw sufficiently to
release the valve.
3. Note the orientation of the valve, rotate it and withdraw
it from the manifold.
Hydraulic Inlet
Assembly
4. Fit the new valve and ‘O’ ring seal and set to the
previously noted orientation. Reassemble in reverse order.
Fig. 77
‘O’ ring seal
Grub Screw
Pressure Relief Valve
Fig. 78
Discharge Pipe
42
© Baxi Heating UK Ltd 2016
13.0 Changing Components
13.20
Plate Heat Exchanger (Fig. 79)
1. Drain the boiler primary circuit and remove the gas valve
as described in section 13.25.
Plate Heat Exchanger
2. While supporting the heat exchanger undo the screws
securing it to the brass manifolds.
3. Withdraw the heat exchanger upwards, taking care not to
damage any wires or controls.
Seals
4. There are four rubber seals between the manifolds and
heat exchanger which may need replacement.
LH Location Stud
Fig. 79
5. Ease the seals out of the manifold. Replace carefully,
ensuring that when the seal is inserted into the manifold it is
parallel and pushed fully in.
Rubber Seal
6. When fitting the new heat exchanger note that the left
hand location stud is offset towards the centre more than the
right hand one.
7. Reassemble in reverse order.
13.21
Diverter Valve - Motor Unit & Assembly
(Fig. 80)
1. To replace the motor unit, disconnect the multi-pin plug.
2. Pull off the retaining clip and remove the motor unit.
Motor Unit
3. The motor unit can now be replaced, or the valve
assembly removed.
Multi-pin Plug
Retaining Clip
4. Drain the primary circuit and draw off any hot water once
the isolating taps are closed.
5. Undo the nuts on the tap rail under the boiler. Remove
the screws securing the valve assembly to the boiler bottom
panel and plate heat exchanger.
Valve
Assembly
6. Remove the valve assembly. Examine any seals or washers,
replacing if necessary. Transfer the DHW NTC to the new
valve and reassemble in reverse order.
Fig. 80
Pressure Sensor
© Baxi Heating UK Ltd 2016
43
13.0 Changing Components
13.22
P.C.B. (Fig. 81 & 82)
1. Note the settings of the temperature control knobs,
rotate them fully anticlockwise and carefully pull them off
the drive pins.
2. Completely undo the screws securing the control box
cover and release the cover retaining barbs from their slots.
Disengage the rear of the cover from the control box hinge
pin.
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. Transfer
the control knob drive pins to the new P.C.B. and turn them
fully anticlockwise.
Control Box Cover
Fig. 81
5. Reassemble in reverse order, ensuring that the
temperature controllers are reset to their previous positions.
P.C.B.
13.23
Selector
Switch
Pump P.C.B. (Figs. 81 & 82)
1. Completely undo the screws securing the control box
cover and release the cover retaining barbs from their slots.
Drive Pins
Pump
P.C.B.
2. Note the position of all plugs and wires on the P.C.B. and
disconnect them. Undo the securing screws and remove the
P.C.B.
3. Reassemble in reverse order.
13.24
Selector Switch (Fig. 82)
1. Note the setting of the selector switch knob and carefully
pull it off the facia.
Facia
Selector Switch Knob
Fig. 82
Temperature Control Knobs
2. Completely undo the screws securing the control box
cover and release the cover retaining barbs from their slots.
Disengage the rear of the cover from the control box hinge
pin (Fig. 97).
3. Note the position of the electrical connections and the
orientation of the switch. Remove the electrical connections.
4. Remove the screws securing the switch to the facia panel.
5. Fit the new switch, ensuring that it is correctly positioned
and reassemble in reverse order.
44
© Baxi Heating UK Ltd 2016
13.0 Changing Components
Venturi Inlet
Pipe
13.25
Gas Valve (Fig. 83)
IMPORTANT: After replacing the valve the CO2 must be
checked and adjusted as detailed in Section 14.0 Setting
the Gas Valve. Only change the valve if a suitable
calibrated combustion analyser is available, operated by a
competent person - see section 12.1.
Gas Valve
Sensing Pipe
1. Turn the gas cock off and undo the nut on the gas feed
elbow under the boiler.
Power Lead
2. Remove the screws securing the gas valve to the boiler
bottom panel.
3. Pull off the power lead, earth lead and sensing pipe.
Earth Lead
Gas Feed
Elbow
4. Undo the nut on the gas pipe at the gas/air inlet and the gas
valve. Remove the pipe, taking care not to lose the sealing
washers. Remove the valve.
5. Remove the outlet adaptor and inlet pipe and transfer them
to the new valve. Examine the ‘O’ ring seals, replace if
necessary.
Fig. 83
Throttle
Adjustment Screw
6. Reassemble in reverse order., ensuring that all seals are in
place and the injector is fitted.
NOTE: To assist the boiler to light prior to final setting,
use a suitable hexagon key to wind out the throttle
adjustment screw until it is flush with the valve body, then
turn the screw 4 full turns clockwise (Fig. 84). If the boiler
will not light, or the correct CO2 cannot be achieved call
Baxi Customer Support 0344 871 1545.
Fig. 84
13.26
Expansion Vessel (Fig. 85)
1. Drain the boiler primary circuit and undo the nut on the
vessel connection pipe.
Retaining Bracket
2. Remove the screw retaining the air inlet pipe, and swing the
pipe to one side.
Expansion Vessel
3. Undo and remove the locknut securing the vessel spigot to
the boiler lower panel.
4. Remove the bracket and vessel from the boiler.
5. Locate the retaining bracket on the upper flange of the new
vessel and fit to the boiler.
6. Examine the sealing washer, replacing if necessary, and
reassemble in reverse order.
Lock Nut
Boiler Chassis
Fig. 85
© Baxi Heating UK Ltd 2016
45
x2
14.0 Setting the Gas Valve
14.1
Central Heating
Temperature Control
Selector Switch
Setting the Gas Valve (CO2 check)
IMPORTANT: The CO2 must be only be checked and
adjusted to set the valve if a suitable calibrated
combustion analyser is available, operated by a
competent person - see Section 12.1
Fig. 86
Domestic Hot Water
Temperature Control
1. The combustion (CO2) may be checked after running the
boiler for several minutes. To do this it is necessary to set
the boiler to ‘Calibration Mode’.
Display
2
1
12
11
3
7
10
9
0
4
2
1
12
11
Central Heating
Temperature Control
3
bar
2. Ensure that all external controls are calling for heat. The
actual current boiler temperature is shown on the display.
5
4
0
AM
8
3
7
1
8
PM
9
5
10
4
2
Reset
3. Turn both control knobs fully anticlockwise, then quickly
turn the right hand knob 1/4 clockwise twice and back fully
anticlockwise (Fig. 86).
Domestic Hot Water
Temperature Control
4. The display will now alternate between ‘SF’ and the
current boiler temperature and both green LEDs will flash
(Figs. 87 & 88).
5. Turn the left hand knob fully clockwise. As the knob is
turned the display will change, indicating the fan speed.
Fig. 88
Fig. 87
6. The display will show ‘00’, indicating maximum rate, then
revert to ‘P ‘ alternating with the current boiler temperature
(Figs. 89, 90 & 91).
Fig. 90
Fig. 89
7. Remove the plug from the flue sampling test point. Insert
the analyser probe and allow sufficient time for the reading
to settle (Fig. 92).
The CO2 should be 8.7% ± 0.2
Fig. 91
Flue Adaptor Test
Point
8. It is possible to alter the CO2 by adjustment of the gas
valve. Remove the plastic cover from the Throttle
Adjustment Screw. At maximum rate the Throttle
Adjustment Screw should be turned, using a suitable
hexagon key, until the correct reading is obtained (Fig. 93).
Turning clockwise will reduce the CO2. Anticlockwise will
increase the CO2.
Plug
Analyser Probe
Fig. 92
Offset
Adjustment Screw
(cap fitted)
Reduce CO2
at min. rate
Increase CO2
at min. rate
If the CO2 is reset at minimum
rate it must be rechecked at
maximum rate again and adjusted
if required. If the CO2 is reset at
maximum rate it must be
rechecked at minimum rate and
adjusted if required.
46
Throttle
Adjustment Screw
(cover removed)
© Baxi Heating UK Ltd 2016
Reduce CO2
at max. rate
Gas Valve
Increase CO2
at max. rate
Fig. 93
Do not turn the adjustment
screws more than 1/8 of a turn at
a time. Allow the analyser reading
to settle before any further
adjustment
9. The CO2 must then be checked at minimum rate. Turn
the left hand knob fully anti-clockwise. As the knob is turned
the display will change, indicating the fan speed. When the
display reads ‘ 0’ the boiler runs at minimum rate.
The CO2 should be 8.4% ± 0.2
10. With the boiler on minimum, the Offset Adjustment
Screw must be altered, using a suitable hexagon key, after
removing the cap (Fig. 93). Turning anti-clockwise will reduce
the CO2. Clockwise will increase the CO2.
11. The ‘Calibration Function’ is maintained for 20 minutes
unless the maximum CH temperature is exceeded. The
function can be disabled at any time by turning the right
hand knob.
12. Check the Combustion Performance (CO/CO2 ratio).
This must be less than 0.004.
15.0 Electrical
15.1
Illustrated Wiring Diagram
Air
Pressure
Switch
Central Heating
NTC Sensor
DHW
NTC Sensor
b
b
Overheat Stat
2
Hall Effect
Sensor
b
r
Water Pressure
Switch
1
b
r
Flue Sensor
1
4
2
g
b
r
br
5
b
w
b
g
g
bk
Fan
3
1
2
b
g/y
b
b
br
Flame
Sensing
Electrode
X400
1
X401
9 87 6 5 4 3 2 1
2
3
4
10 9 8 7 6 5 4 3 2 1
Timer (where fitted)
Pump
(Grundfos)
3
bk
b
X9
X501
br
2
Control PCB
1
4
bk
1
2
1
X1
2
3
1
5
2
3
5
4
6
7
8
9
g/y
X3
Pump
PCB
6 Way
Connector
4
X2
b
br
b
br
r
bk
g/y
br
b
b
br
w
bk
br
b
X1
b
r
br
br
Pump
(Wilo)
b
X2
X3
w
r
L
br
Spark
Generator
N
b
bk
b
a
b
Diverter Valve
br
bk
g or w
w
br
Gas Valve
b
Link
g/y
Ignition
Electrode
b
bk
br
r
Mains Input Cable
br
bk
b
w
© Baxi Heating UK Ltd 2016
- brown
- black
- blue
- white
g
- green
g/y - green / yellow
r
- red
47
16.0 Short Parts List
Short Parts List
426
306
315
316
311
Key
No.
422
420
Fan
5121447
426
Motor 3 way Valve
5132452
315
Igniter Electrode
720222801
316
Sensing Electrode
720222901
422
Gas Valve
720301001
404
Hall Effect Sensor
5114767
306
Burner 24/28
5122149
Burner 33
5114697
Burner 40
5114698
419
Water Pressure Switch
5114748
400
Plate Heat Exchanger
5114708
415
Pump
7654033
421
NTC Sensor
5114725
517
420
Overheat Thermostat
5114729
504
Pressure Gauge
248090
503
302
PCB 24
5121862
PCB 28
720043401
PCB 33
720795201
PCB 40
5122287
517
Pump PCB
7222704
505a
Air Pressure Switch
7648326
421
415
505a
© Baxi Heating UK Ltd 2016
Manufacturers
Part No.
311
400
48
Description
419
404
503
G.C.
No.
504
17.0 Fault Finding
17.1
NOTE: When instructed to turn the
selector to the reset position turn the
selector switch fully anticlockwise against
the spring pressure to the reset position
and hold for 5 seconds to reset the
boiler.
Initial Fault Finding Checks
1. Check that gas, water and electrical supplies are available
at the boiler.
2. Electrical supply = 230V ~ 50 Hz.
3. CH water system pressurised to 0.5 bar minimum when
the boiler is cold.
4. The preferred minimum gas pressure is 20 mbar.
5. 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.
6. 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.
Table Of Error Codes
17.2
E20
E28
E50
E110
E119
E125
E130
E133
E160
E193
Central Heating NTC Fault
Flue NTC Fault, Air Pressure Switch Fault, Blocked Flue,
Blocked Condensate or Wiring Fault
Hot Water NTC Fault
Safety Thermostat Operated
Water Pressure Switch Not Operated
Circulation Fault (Primary Circuit)
Flue NTC Operated
Interruption Of Gas Supply or Flame Failure
Fan or Fan Wiring Fault
Pre-Circulation Fault
Error Codes
1. If a fault occurs on the boiler an error code may be shown
by the facia display.
2. The codes are either two or three digit, preceded by the
letter 'E'. For example, code E133 will be displayed by 'E1'
alternating with '33'. E50 is shown as 'E' then '50'
E20 & E50 indicate faulty components. E28 includes possible
faulty components or blockage.
E110 shows overheat of the primary water and E130
overheat of the flue system.
Testing Air Pressure Switch
3
To check the Air Pressure Switch is operating correctly:During normal operation or standby briefly apply light suction to
the negative pressure spigot (P2). Error Code “E28” should display
whilst suction is applied, and then disappear when the switch is
remade (removal of suction).
2
1
Connect to terminals
1 & 2 (3 not used)
E119 is displayed when the primary water pressure is less
than 0.5 bar.
E133 indicates that the gas supply has been interrupted,
ignition has failed or the flame has not been detected.
E125 is displayed in either of two situations:i) If within 15 seconds of the burner lighting the boiler
temperature has not changed by 1°.
ii) If within 10 minutes of the burner lighting the boiler
temperature twice exceeds the selected temperature by 30°.
In these instances poor primary circulation is indicated.
3. By turning the selector switch to the 'Reset' position for a
minimum of 5 seconds when E110, E130 & E133 are
displayed it is possible to relight the boiler.
P2 - Negative Pressure
4. If this does not have any effect, or the codes are displayed
regularly further investigation is required.
© Baxi Heating UK Ltd 2016
49
17.0 Fault Finding
Refer to Section 15.0 “Illustrated Wiring Diagram” for position of terminals and components
Central Heating - Follow operational sequence
Turn selector switch to
The display illuminates
NO
Go to section ‘A’
YES
Error 110 flashing
Error 130 flashing
Error 133 flashing
YES
Turn the selector switch to
reset position for 5 seconds
YES
If the error 110 is still flashing.
Go to section ‘J’
NO
Error 20, 28 or 50 flashing
YES
Go to section ‘E’
NO
YES
Error 119 flashing
Go to section ‘C’
Ensure controls are set to
demand and verify the
contacts are closed
NO
NO
Turn Central Heating
thermostat to Maximum.
Pump runs
NO
Ensure all controls (and
integral clock if fitted) are
calling for heat
YES
Go to section ‘B’
YES
Error 125 or 193 flashing
YES
Ensure that primary
circulation is OK & that
there is no blockage
NO
3-way valve is open to Central
Heating circuit
NO
Go to section ‘K’
YES
NO
Fan runs
Error 160 flashing
Go to section ‘D’
Error 28 flashing
Go to section ‘E’
YES
Fan runs at correct speed
NO
YES
Spark at ignition electrodes for
up to 5 seconds and for 3
attempts
YES
NO
Error 133 flashing
YES
Go to section ‘H’
Turn the selector switch to
reset
Go to section ‘F’
NO
YES
Burner lights
NO
YES
© Baxi Heating UK Ltd 2016
YES
Error 133 flashing
Go to section ‘I’
YES
Pump continues to run for 3
minutes
(room thermostat open)
Error 130 flashing
Go to section ‘M’
Error 28 flashing
Go to section ‘E’
Burner output modulates to
maintain the temperature set
Burner goes out
Burner does not stay alights
after 5 seconds
Check the Central Heating
NTC sensor
Go to section ‘E’
YES
50
Error 160 flashing
Go to section ‘L’
Error 28 flashing
Go to section ‘E’
YES
Fan stops after 10 seconds
YES
Operation sequence
successful
57
17.0 Fault Finding
Domestic Hot Water - Follow operational sequence
Turn selector switch to
The display illuminates
NO
Go to section ‘A’
YES
Error 110 flashing
Error 133 flashing
YES
Turn the selector switch to
reset position for 5 seconds
YES
If the error 110 is still flashing.
Go to section ‘J’
NO
YES
Error 20, 28 or 50 flashing
Go to section ‘E’
NO
YES
Error 119 flashing
Go to section ‘C’
Go to section ‘B’
NO
Turn Domestic Hot Water
thermostat to Maximum.
Open DHW tap fully.
DHW Hall Effect sensor
operated (red neon on the
sensor illuminated
YES
NO
DHW flow rate more than 2
l/min
YES
YES
NO
3-way valve is open to
Domestic Hot Water circuit
Is mains water filter and
assembly clean?
Is the magnetic detector free
to move in the Hall Effect
sensor
Go to section ‘K’
YES
Pump runs
NO
Error 125 flashing
Go to section ‘B’
NO
Error 160 flashing
Go to section ‘D’
Error 28 flashing
Go to section ‘E’
NO
Error 160 flashing
Go to section ‘L’
Error 28 flashing
Go to section ‘E’
YES
Fan runs
YES
Fan runs at correct speed
YES
Spark at ignition electrodes for
up to 5 seconds and for 3
attempts
YES
NO
Error 133 flashing
YES
Go to section ‘H’
Turn the selector switch to the
reset position for 5 seconds
Go to section ‘F’
NO
Burner lights
YES
Burner does not stay alights
after 5 seconds
YES
Error 133 flashing
Go to section ‘I’
NO
Reduce DHW flow rate
Burner modulates
NO
Clean DHW NTC sensor
and DHW heat exchanger
YES
Burner output modulates to
maintain the temperature set
YES
NO
Close DHW tap
Error 130 flashing
Go to section ‘M’
Error 28 flashing
Go to section ‘E’
YES
DHW flow sensor senses no
flow. Burner goes out
© Baxi Heating UK Ltd 2016
YES
Fan stops after 10 seconds
YES
Pump runs for 30 seconds
YES
Operation sequence
successful
51
17.0 Fault Finding
Fault Finding Solutions Sections
A
Is there 230V at:
1.
Main terminals L and N
2.
Main terminal fuse
3.
B
NO
Check electrical supply
NO
Replace fuse
NO
Check wiring
PCB - X1 connector
terminals 1,2
NO
Display
illuminated
Is there 230V at:
1.
X3 Connection Pump PCB
NO
Check incoming wiring
YES
X2 Connection Pump PCB
NO
Replace Pump PCB
YES
NO
X1 Control PCB
Check wiring
YES
X3 Control PCB, T3, T4
NO
Replace Control PCB
YES
NO
X1 Pump PCB
Replace Pump PCB
YES
Replace Pump
C
1.
YES
CH system pressure less than 0.5 bar
NO
2.
D
1.
Check the tap of the automatic air
vent is opened
Fan connections correct at fan. PCB X2 connector, is 230V AC across
terminals 5 & 7
Re-pressurise system
Check connection water pressure
switch terminal
COM - NO and PCB connector
X400 terminals 3,4
NO
YES
Fan jammed or faulty winding
Replace PCB
© Baxi Heating UK Ltd 2016
Replace water
pressure switch
Open the automatic air vent
NO
52
YES
YES
Replace fan
Replace PCB
17.0 Fault Finding
E
Temperature sensors faulty.
Cold resistance approximately
10k @ 25° C (DHW and CH sensors)
20k @ 25° C (Flue sensor)
(resistance reduces with increase in temp.)
NO
NO
Air Pressure Switch faulty.
Check for continuity across terminals 1 & 2
YES
Flue blocked or damaged
Replace sensor
Replace switch
Unblock or repair flue
YES
Unblock
Condensate trap or pipework blocked
F
1.
2.
Check and correct the connection of the
tube between the venturi and gas valve
Gas at burner
NO
Ensure gas is on and purged
PCB - X3 connector is 230V AC across
terminals 1 & 2
YES
Replace gas valve
NO
Replace PCB
G
1.
Ensure that the Hall Effect Sensor is in position.
Check the connection between the PCB - X400
connector terminals 3,6,7 and the electronic sensor
YES
Check the voltage between red wire and blue
wire is more than 5V DC
YES
NO
Replace PCB
Check and correct if necessary
1. Ignition electrode and lead
2. Electrode connection
3. Spark gap and position
NO
YES
Replace PCB
Replace igniter
4 ±0.5
YES
Voltage at PCB - X2 connector is at
least 100V DC across terminals 2 & 5
(Note: from multimeter connect
‘common’ to 2 & ‘volts’ to 5).
Check wiring
Burner
Viewing Window
Sensing
Electrode
Spark Ignition
Electrode
±1
7.5
H
Replace Hall
Effect Sensor
10 ±1
Electrode Position
© Baxi Heating UK Ltd 2016
53
17.0 Fault Finding
I
1.
2.
Check supply pressure at the
gas valve:Minimum 17 mbar
Check and correct if necessary
1. The mechanical set of the gas valve
(CO2 values - see instruction)
2. Flame sensing electrode and lead connections
3. Flame sensing electrode position
YES
Flame current should be more than 0.5 A
J
1.
Overheat thermostat operated or
faulty, i.e. continuity across
thermostat terminals
NO
NO
Replace PCB
Replace flame sensing electrode
Allow to cool. Continuity
across thermostat terminals
more than 1.5 ohm
YES
YES
Replace PCB
K
Is there 230V at:
1.
Motor 3-way valve
2.
PCB - X3 connector terminals
5 & 6 central heating mode
5 & 7 domestic hot water mode
YES
Replace motor 3-way valve
NO
Replace PCB
YES
Change pump supply cable
L
1.
M
1.
Fan connections correct at fan.
PCB - X401 connector terminals 5,6,7 & 8
Temperature sensors faulty.
Cold resistance approximately
10k @ 25° C (CH sensor)
20k @ 25° C (Flue sensor)
(resistance reduces with increase in temp.)
YES
NO
YES
2.
54
If pump is running the heat exchanger could be
obstructed
© Baxi Heating UK Ltd 2016
Replace fan
Replace sensor
Replace heat exchanger
Replace safety thermostat
18.0 Notes
© Baxi Heating UK Ltd 2015
55
18.0 Notes
56
© Baxi Heating UK Ltd 2015
18.0 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.
7654277 - 02 (11/16)
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