Potterton 15 HE Plus Installation and maintenance instructions

© Baxi Heating UK Ltd 2009
Installation & Service Instructions
These instructions include the Benchmark Commissioning Checklist
and should be left with the user for safe keeping.
Promax
15/2,24/2 & 30
HE Plus
Condensing
Central Heating Boiler
You can rely on

2© Baxi Heating UK Ltd 2009
Natural Gas
Potterton Promax 15/2 HE Plus
G.C.No41 605 52
Potterton Promax 24/2 HE Plus
G.C.No41 601 17
Potterton Promax 30 HE Plus
G.C.No41 601 22
© Baxi Heating UK Ltd 2009 All rights reserved. No part of this publication may
be reproduced or transmitted in any form or by any means, or stored in any
retrieval system of any nature (including in any database), in each case whether
electronic, mechanical, recording or otherwise, without the prior written
permission of the copyright owner, except for permitted fair dealing under
Copyrights, Designs and Patents Act 1988.
Applications for the copyright owner’s permission to reproduce or make other
use of any part of this publication should be made, giving details of the proposed
use, to the following address:
The Company Secretary, Baxi Heating UK Ltd, The Wyvern Business Park,
Stanier Way, Derby, DE21 6BF.
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.
This product has an energy rating (A) on a scale of A to G.
For more information see www.boilers.org.uk. This is a certification mark.
0086
ISO 9001
FM 00866
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.
These arrangements represent a change from the situation
whereby compliance with Building Regulations was accepted as
being demonstrated by completion of the Benchmark Logbook
(which was then left on site with the customer).
With the introduction of Self Certification Schemes, the
Benchmark Logbook is being withdrawn. However, a similar
document in the form of a commissioning checklist and service
interval record is incorporated at the back of these instructions.
This company is a member of the Benchmark initiative and fully
supports the aims of the programme. Its aim is to improve the
standards of installation and commissioning of central heating
systems in the UK and to encourage the regular servicing of all
central heating systems to ensure safety and efficiency.
Building Regulations require that installations should comply
with manufacturer's instructions. It is therefore important that
the commissioning checklist is completed by the installer. The
relevant section of Building Regulations only relates to
dwellings. Therefore the checklist only applies if the appliance is
being installed in a dwelling or some related structure.
The flowchart opposite gives guidance for installers on the
process necessary to ensure compliance with Building
Regulations.
The Benchmark Scheme
Benchmark places responsibilities on both manufacturers and installers. The
purpose is to ensure that customers are provided with the correct equipment for
their needs, that it is installed, commissioned and serviced in accordance with the
manufacturer’s instructions by competent persons and that it meets the
requirements of the appropriate Building Regulations. The Benchmark Checklist
can be used to demonstrate compliance with Building Regulations and should be
provided to the customer for future reference.
Installers are required to carry out installation, commissioning and servicing work
in accordance with the Benchmark Code of Practice which is available from the
Heating and Hotwater Industry Council who manage and promote the Scheme.
Visit www.centralheating.co.uk for more information.

Installer Notification Guidelines
3
© Baxi Heating UK Ltd 2009
Choose Building
Regulations Notification
Route
Contact your relevant Local
Authority Building Control
(LABC) who will arrange
an inspection or contact
a government approved
inspector
LABC will record the data
and will issue a
certificate of compliance
‘Gas Safe Register’ will issue a
Building Regulations Compliance
Certificate to the property owner
and inform the relevant LABC
You must ensure that the
certificate number issued by
the ‘Gas Safe Register’ is written
onto the Benchmark Checklist
Scheme Members only
Call ‘Gas Safe Register’ on:
0800 408 5577
or log onto:
www.GasSafeRegister.co.uk
within 10 days
If you notify via the ‘Gas Safe
Register’, the register will issue
the Building Regulations
certificate on members’ behalf
Complete the
Benchmark Checklist
Install and Commission this
appliance to manufacturer's
instructions
Competent Person's
Self Certification Scheme
Building Control
Complete the
Benchmark Checklist
Install and Commission this
appliance to manufacturer's
instructions

Legislation
4© Baxi Heating UK Ltd 2009
This company declares that no substances harmful
to health are contained in the appliance or used
during appliance manufacture.
The appliance is suitable only for installation in GB and IE
and should be installed in accordance with the rules in
force, and only used in a suitably ventilated location.
In GB, the installation must be carried out by a Gas Safe
Registered Installer. It must be carried out in accordance
with the relevant requirements of the:
• Gas Safety (Installation & Use) Regulations.
• The appropriate Building Regulations either The Building
Regulations, The Building Regulations (Scotland), Building
Regulations (Northern Ireland).
• The Water Fittings Regulations or Water Byelaws in
Scotland.
• The Current I.E.E. Wiring Regulations.
Where no specific instructions are given, reference should
be made to the relevant British Standard Code of Practice.
In IE, the installation must be carried out by a competent
Person and installed in accordance with the current edition
of I.S. 813 ‘Domestic Gas Installations’, the current Building
Regulations and reference should be made to the current
ETCI rules for electrical installation.
All systems must be thoroughly flushed and treated
with inhibitor (see section 6.2).
IMPORTANT - Installation, Commissioning, Service & Repair
This appliance must be installed in accordance with the manufacturer’s instructions and
the regulations in force. Read the instructions fully before installing or using the
appliance.
In GB, this must be carried out by a competent person as stated in the Gas Safety
(Installation & Use) Regulations.
Definition of competence: A person who works for a Gas Safe registered company
and holding current certificates in the relevant ACS modules, is deemed competent.
In IE, this must be carried out by a competent person as stated in I.S. 813 “Domestic
Gas Installations”.
NOTE: The addition of anything that may interfere with the normal operation of the
appliance without express written permission from the manufacturer or his agent could
invalidate the appliance warranty. In GB this could also infringe the Gas Safety
(Installation and Use) Regulations.
Warning - Check the information on the data plate is compatible with local supply
conditions.
Codes of Practice, most recent version should be used
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 5449 Forced circulation hot water 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 BS standards give valuable additional information;
BS 5546 Installation of hot water supplies for domestic
purposes.
BS 5449 Forced circulation hot water systems.
BS 7074 Expansion vessels and ancillary equipment for
sealed water systems.
BS 7593 Treatment of water in domestic hot water
central heating systems.
The boiler meets the requirements of Statutory Instrument “ The Boiler (Efficiency)
Regulations 1993 No3083” and is deemed to meet the requirements of Directive
92/42/EEC on the energy efficiency requirements for new hot water boilers fired with
liquid or gaseous fuels:-
Type test for purpose of Regulation 5 certified by:
Notified Body 0087.
Product/Production certified by:
Notified Body 0086.
For GB/IE only.
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

Safe Manual Handling
5
© Baxi Heating UK Ltd 2009
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 section 8.3 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 2009
1.0 Introduction 7
2.0 General Layout 8
3.0 Appliance Operation 9
4.0 Technical Data 10
5.0 Dimensions and Fixings 11
6.0 System Details 12
7.0 Site Requirements 16
8.0 Flue Options 20
9.0 Plume Displacement 25
10.0 Installation 29
11.0 Electrical 35
12.0 Commissioning the Boiler 37
13.0 Fitting the Outer Case 38
14.0 Servicing the Boiler 39
15.0 Changing Components 41
16.0 Short Parts List 48
17.0 Fault Finding 49
Benchmark Checklist 58
Section Page
Contents
6
Contents of Pack
The pack contains:-
• Boiler
• Wall Plate
• Template & ‘Quick Fit’ Guide
• Literature Pack
• Fittings Pack

1.1 Description
1. The Potterton Promax HE Plus are gas fired room
sealed fan assisted condensing central heating boilers.
2. The maximum output of the Potterton Promax 15/2
HE Plus is 52,000 Btu/hr, 24/2 HE Plus is 75,000 Btu/hr.
The maximum output of the 30 HE Pus is preset at
75,000 Btu/hr but can be set to 100,000 Btu/hr (see
section 8.8). All boilers automatically adjust their outputs
according to the system load.
3. It is designed for use on Natural Gas (G20).
4. The boiler is suitable for fully pumped open vented
central heating and domestic hot water systems and
sealed systems.
5. A label giving details of the model, serial number and
Gas Council number is situated on the rear of the lower
door panel (Fig. 1).
6. The boiler data badge is positioned on the air box door
(Fig. 2).
7. The boiler is intended to be installed in residential /
commercial / light industrial E.M.C. 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 236921.
1.2 Important Information
Man-made mineral fibre
• Some component parts of this appliance (insulation
pads, gaskets and rope seals) are manufactured from man-
made mineral fibre.
• Prolonged or excessive exposure to this material may
result in some irritation to the eyes, skin or respiratory
tract.
• It is advisable to wear gloves when handling these items.
• Irritant dust will only be released from the items if they
are broken up or subjected to severe abrasion. In these
instances a suitable dust mask and goggles should be
worn.
• Always thoroughly wash hands after installation,
servicing or changing components.
• When disposing of any items manufactured from man-
made mineral fibre care must be exercised.
• If any irritation of the eyes or severe irritation of the skin
is experienced seek medical attention.
1.0 Introduction
7
© Baxi Heating UK Ltd 2009
Fig. 1
Data Badge
Air Box Door
Lower Door Panel Position of Label
Fig. 2

2.0 General Layout
8© Baxi Heating UK Ltd 2009
2.1 Layout (Figs. 3,4,5 & 6)
1. Wall Plate
2. Flue Elbow
3. Heat Exchanger
4. Burner
5. Air Box
6. Fan Protection Thermostat
7. Fan Assembly
8. Condensate Trap
9. PCB Housing Assembly
10. Gas Tap
11. Gas / Air Ratio Valve
12. Flow Pipe Connection
13. Return Pipe Connection
14. Flow Temperature Safety Thermostat - Black
15. Flow Temperature Thermistor - Red
16. Flow Switch (dry fire protection)
1
2
3
4
5
6
7
9
8
10
11
15 14
12
13
16
Fig. 4
Fig. 3
Fig. 5
Fig. 6

3.0 Appliance Operation
9
© Baxi Heating UK Ltd 2009
3.1
1. Switched Live On: When the switched live switches
on if the flow temperature is less than the set point
then pump overrun occurs. When the switched live
switches on if the flow temperature is greater than the
set point then pump overrun occurs.
2. Pump On: The pump is on while the fan, spark
generator and gas valve are off. After 10 seconds if the
flow switch has made then fan pre-purge occurs. After
10 seconds if the flow switch has not made then anti-
cycle occurs.
3. Fan Pre-Purge: The pump and fan are on while the
spark generator and gas valve are off. After 5 seconds
ignition occurs.
4. Ignition: The pump, fan, spark generator and gas
valve are on. If a flame is detected then burner on
occurs. If a flame is not detected within 5 seconds and
less than 5 ignition attempts have been made then fan
purge occurs. If a flame is not detected within 5
seconds and 5 ignition attempts have been made then
ignition lockout occurs.
5. Burner On: The pump, fan and gas valve are on
while the spark generator is off. Flow temperature is
controlled by varying the fan speed (and thereby the
gas rate) to achieve optimum operation. If the flow
temperature is greater than the set point or the TRVs
all shut down then fan post purge occurs.
6. Fan Post Purge: The pump and fan are on while the
spark generator and gas valve are off. After 5 seconds if
the TRVs are not shut down then pump overrun
occurs. After 5 seconds if the TRVs are shut down then
anti-cycle occurs.
7. Pump Overrun: The pump is on while the fan, spark
generator and gas valve are off. After 1 minute anti-
cycle occurs.
8. Anti-cycle: The pump, fan, spark generator and gas
valve are off. After 3 minutes if the flow temperature is
less than the set point then pump on occurs. After 3
minutes if the flow temperature is greater than the set
point then pump overrun occurs.
9. Ignition Lockout: The pump, fan, spark generator
and gas valve are off. The boiler can only be reset by
manually using the reset button.
Mains On.
Flow
temperature less
than set point ?
YES
5 second
Fan Pre-Purge.
Flame Detected ?
Burner On.
Ignition
Lockout.
5 second
Ignition Period.
All TRVs
shut down ?
Ignition done and
5 attempts made ?
Ignition done
and less than 5
attempts made ?
Flow switch made ?
NO
YES
YES
YES
10 second
Pump On.
All TRVs
shut or Flow temperature
greater than set point ?
5 second
Fan Post Purge.
1 minute
Pump Overrun.
3 minute
Anti-cycle.
NO
YES
YES
YES
NO

Appliance Category CAT I 2H
4.0 Technical Data
10 © Baxi Heating UK Ltd 2009
Horizontal
Flue Terminal Diameter 110mm
Dimensions Projection 150mm
Outercase Dimensions
Overall Height Inc Flue Elbow - 750mm
Casing Height - 600mm
Casing Width - 390mm
Casing Depth - 320mm
Weights kg
Packaged Boiler Carton 36.2
Packaged Flue Kit 3.6
Installation Lift Weight 26.0
Connections
Gas Supply - 1/2in BSPT
Central Heating Flow - 22mm
Central Heating Return - 22mm
Condensate Drain - 1 in BSP
Recommended System
Temperature Drop
Condensing 20°C 36°F
Heat Input (Q)(Gross) Max Min
15/2 HE Plus kW 16.88 10.2
Btu/hr 57,600 34,840
24/2 HE Plus kW 24.50 10.2
Btu/hr 83,600 34,840
30 HE Plus kW 33.76 10.2
(see note) Btu/hr 115,200 34,840
Heat Output (P)
(Non Condensing 70° C Mean Water Temp)
Max Min
15/2 HE Plus kW 15.24 9.14
Btu/hr 52,000 31,180
24/2 HE Plus kW 22.00 9.14
Btu/hr 75,000 31,180
30 HE Plus kW 30.18 9.14
Btu/hr 102,980 31,180
Electrical Supply 230V~ 50Hz
(Appliance must be connected to an
earthed supply)
Power Consumption 80W
External Fuse Rating 3A
Internal Fuse Rating (BS 4265)
Fuse 3.15 AT (PCB)
Inlet Pressure at Gas Valve (Natural Gas)
Min 18.1 mbar
Max 22.5 mbar
(see Section 10.1)
Injector (Natural Gas)
6.5mm Diameter
Clearances
(For unventilated compartments see Section 7.2)
Both Sides 5mm Min
Above Casing 200mm Min
Below Casing 50mm Min
Front (For Servicing) 500mm Min
Front (In Operation) 5mm Min
010203040
20
40
60
80
100
120
140
160
180
200
220
Water Flow Rate (litres/min)
Pressure Drop (mbar)
8
17
25
33
42
50
58
66
75
83
91
Pressure Drop (in wg)
Hydraulic Resistance Chart
Appliance Type C13 C33 C53
Nox Class 5
Heat Output (P)
(Condensing 40° C Mean Water Temp)
Max Min
15/2 HE Plus kW 16.49 10.1
Btu/hr 56,260 34,520
24/2 HE Plus kW 23.8 10.1
Btu/hr 81,200 34,520
30 HE Plus kW 32.61 10.1
Btu/hr 113,280 34,520
Water Content
litres 2.6
pints 4.6
Static Head
max 30 metres (100 ft)
min 1 metre (3.25 ft)
Low Head 0.2m (8 in) min
System Detail
fully pumped open vented & sealed systems
Gas Connection
G1/2” B.S.P. Thread
Controls
boiler thermostat, safety thermostat,
flow switch, electronic flame sensing,
temperature protection thermostat &
condensate blockage sensor
NOTE: The maximum output of the 30 HE
Plus is factory set at 22.0kW (75,000
Btu/hr). This can be altered to 30.18kW
(102,980 Btu/hr) - see section 8.8.
For 15/2 HE Plus - The efficiency is 91.3%
For 24/2 HE Plus - The efficiency is 90.9%
For 30 HE Plus - The efficiency is 90.9%
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 0087.
SEDBUK Declaration
Electrical Protection IPX2
CO/CO2 Ratio Up to a maximum
of 0.004
Flow Temperature (adjustable)
55° C to 78° C (± 5° C)
Max Gas Rate (2H - G20 - 20mbar)
(After 10 Mins)
(15/2) (24/2) (30)
Btu/hr 52,000 75,000 102,980
m3/hr 1.64 2.31 2.95
ft3/hr 52.1 83.3 104.2
CO2 Level 9% ± 1%