Potterton Promax 15 HE Installation and maintenance instructions

Installation & Service Instructions Promax
15 HE & 24 HE
This is a Wall Mounted Powered Flue Condensing Boiler Gas Fired Central Heating Unit.
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 0086.
Product/Production certified by:
Notified Body 0086.
For use with Natural Gas (G20) only at 20mbar and for use in GB/IE only.

Publication No. 5106451
2
Natural Gas
Potterton Promax 15 HE
G.C.No41 590 58
Potterton Promax 24 HE
G.C.No41 590 62

3
CONTENTS
Publication No. 5106451
0.0 Legislation 4
1.0 Introduction 5
2.0 General Layout 6
3.0 Appliance Operation 7
4.0 Technical Data 8
5.0 Dimensions and Fixings 9
6.0 System Details 10
7.0 Site Requirements 13
8.0 Installation 19
9.0 Electrical 25
10.0 Commissioning 27
11.0 Outer Case 28
12.0 Servicing 29
13.0 Changing Components 31
14.0 Fault Finding 38
15.0 Short Parts List 43
Section Page

0.0 LEGISLATION
4Publication No. 5106451
Codes of Practice, most recent version should
be used
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 CORGI registered
company and holding current certificates in the relevant ACS modules, or
valid ACoP equivalents, is deemed competent.
In IE, this must be carried out by a competent person as stated in I.S. 813
“Domestic Gas Installations”.
Lifting - This product should be lifted and handled by two people. For
recommended hand holds see section 8.3. Stooping should be avoided and
protective equipment worn where necessary. Carrying & lifting equipment
should be used as required, e.g. when installing in a loft space.
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.
“Benchmark” Log Book
As part of the industry-wide “Benchmark”initiative all Potterton boilers now
include an Installation, Commissioning and Service Record Log Book. Please
read the Log Book carefully and complete all sections relevant to the
appliance and installation. These include sections on the type of controls
employed, flushing the system, burner operating pressure etc. The details of
the Log Book will be required in the event of any warranty work. Also, there is
a section to be completed at each subsequent regular service visit. The Log
Book must be left with the user.
All CORGI registered installers carry a CORGI identification card and have a
registration number. Both should be recorded in your boiler Log Book. You
can check your installer is registered by telephoning [phone] or
writing to:-
1 Elmwood,
Chineham Business Park,
Crockford Lane,
Basingstoke. RG24 8WG
Potterton 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 CORGI
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).
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.

5
1.0 INTRODUCTION
Publication No. 5106451
1.1 Description
1. The Potterton Promax 15 HE and 24 HE are gas
fired room sealed fan assisted condensing central
heating boilers.
2. The maximum output of the Potterton Promax 15
HE is 52,000 Btu/hr. The maximum output of the
Potterton Promax 24 HE is 75,000 Btu/hr. Both
boilers automatically adjust their outputs down to
30,000 Btu/hr 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 top of the
outercase (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.
Fig. 1
Data Badge
Air Box Door
Fig. 2
Label

2.0 GENERAL LAYOUT
6Publication No. 5106451
2.1 Layout (Figs. 3,4 & 5)
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. On/Off/Lockout Reset Switch
10. Gas Tap
11. Gas / Air Ratio Valve
12. Electronics Housing
13. Transformer
14. Flow Pipe Connection
15. Return Pipe Connection
16. Flow Temperature Safety Thermostat - Black
17. Flow Temperature Thermistor - Red
18. Flow Switch (dry fire protection)
1
2
3
4
5
6
7
9
8
10
11
12
13
17 16
14
15
18
Fig. 4
Fig. 3
Fig. 5
2.2 Optional Extras
KIT PART No
FLUE EXTENSION KITS (110/70)
Flue Extension 0.25M 241692
Flue Extension 0.5M 241694
Flue Extension 1M (Use two kits for 2M etc.) 241695
Flue Bend x 2 - 45°(Reduce overall length of flue
by 0.5m when fitting this bend) 241689
Flue Bend - 90°(Reduce overall length of flue
by 1m when fitting each bend) 241687
Horizontal Extended Flue (1.75M) 5111457
VERTICAL FLUE (110/70)
Vertical Flue Terminal 242802
Vertical Flue Adaptor 5106888

7
3.0 APPLIANCE OPERATION
Publication No. 5106451
3.1
1. Switched Live On: When the switched live
switches on pump overrun occurs.
2. Pump Overrun: The pump is on while the fan,
spark generator and gas valve are off. If at any stage
during pump overrun the flow temperature is less
than the set point and the flow switch is made then
fan purge occurs. After 1 minute of pump overrun
anti-cycle occurs.
3. Fan 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 the 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 then pump
overrun occurs. If the TRVs all shut down then anti-
cycle occurs.
6. Anti-cycle: The pump, fan, spark generator and
gas valve are switched off. After 3 minutes pump
overrun occurs.
7. Ignition Lockout: The pump, fan, spark generator
and gas valve are switched off. The boiler can only
be reset by manually using the thermostat knob.
Mains On.
Flow
temperature less
than set point and flow
switch made ?
YES
5 second
Fan Purge.
Flame Detected ?
Burner On. Ignition
Lockout.
5 second
Ignition Period.
All TRVs
shut down ?
Flow temperature
greater than set
point ?
Ignition done and
5 attempts made ?
Ignition done
and less than 5
attempts made ?
Pump Overrun
Anti-cycle.
Pump Overrun
for 1 minute ?
YES
YES
YES
YES
YES
YES

4.0 TECHNICAL DATA
8Publication No. 5106451
Appliance Category CAT I 2H
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 lb
Packaged Boiler Carton 40.7 89.6
Packaged Flue Kit 3.6 8.0
Weight Empty 38.2 84.1
Installation Lift Weight 31.5 69.3
Connections
Gas Supply - 1/2in BSPT
Central Heating Flow (HE15) - 28mm
Central Heating Flow (HE24) - 28mm
Central Heating Return (HE15) - 28mm
Central Heating Return (HE24) - 28mm
Condensate Drain - 1 in BSP
Recommended System
Temperature Drop
Normal 11°C20°F
Condensing 20°C36°F
Heat Input (see note) Max Min
15 HE kW 16.88 10.2
Btu/hr 57,600 34,840
24 HE kW 24.50 10.2
Btu/hr 83,600 34,840
Heat Output
(Non Condensing 70°C Mean Water Temp)
Max Min
15 HE kW 15.24 9.14
Btu/h 52,000 31,180
24 HE kW 22.0 9.14
75,000 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 (2) 4 AT (Control Board)
Fuse (3) 2 AT (Ignition Board)
Max Gas Rate (Natural Gas)
(After 10 Mins)
Btu/hr 75,000 52,000
m3/h 2.31 1.64
ft3/h 83.3 52.1
Inlet Pressure at Gas Valve (Natural Gas)
Min 18.1 mbar
Max 22.5 mbar
(see Section 10.1)
Injector (Natural Gas)
6.3mm Diameter
Clearances
Both Sides 5mm Min
Above Casing 200mm Min
Below Casing 130mm Min
Front (For Servicing) 500mm Min
Front (In Operation) 5mm Min
0 10203040
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
Nox Class 5
Heat Output
(Condensing 40°C Mean Water Temp)
Max Min
15 HE kW 16.49 10.1
Btu/h 56,260 34,520
24 HE kW 23.8 10.1
81.200 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
RC1/2(1/2in BSPT)
Controls
installer preset boiler thermostat, safety
thermostat, flow switch, electronic flame
sensing,temperature protection thermostat
& condensate blockage sensor
The efficiency is
Promax 15 HE - 91.3%
Promax 24 HE - 91.0%
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 0086.
SEDBUK Declaration For
Potterton Promax 15 HE & 24 HE

9
5.0 DIMENSIONS AND FIXINGS
Publication No. 5106451
DIMENSIONS
A600mm
B320mm
C390mm
D125mm ØMin.
E150mm
F125mm
SIDE FLUE (left and right)
For every 1m of horizontal flue
length, the clearance above the
top of the flue elbow should be
55mm to incorporate the 3°
(1 in 20) fall in the flue from the
terminal to the elbow.
The 3°(1 in 20) fall provided by
the elbow is to allow condensate
to run back to the boiler, for
disposal through the condensate
discharge pipe.
Flue length (Y)
up to 1m
1m - 2m
2m - 3m
Clearance (X)
55mm
110mm
165mm
360°Orientation
Tube Ø110mm
DC
B
A
E
F
Y
3°
(1 in 20)
X
3°
(1 in 20)
Fig. 6
Fig. 7

6.0 SYSTEM DETAILS
10 Publication No. 5106451
6.1 Water Circulating Systems
1. The appliance is suitable for use with open vent
fully pumped systems and sealed systems .
The following conditions should be observed on
all systems:
•The static head must not exceed 30m (100ft)
of water.
•The boiler must not be used with a direct
cylinder.
•Drain cocks should be fitted to all system low
points.
•All gas and water pipes and electrical wiring
must be installed in a way which would not
restrict the servicing of the boiler.
•Position isolating valves as close to circulating
pump as possible.
•It is recommended that the return pipe is fitted
with an automatic air vent as close to the boiler
as is practical.
NOTE: Full TRV Systems (refer to section 6.4)
Where all the radiators are controlled by TRV’s then
pump protection will be required. This can be done by
either of the options opposite (see Fig A & B). The
option shown in Fig. A should only be used on a
full TRV system without a bypass. Fig. B shows a
system with a bypass that must be capable of
allowing a flow of at least 3 l/min.
6.2 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 upgrading existing systems that exhibit
evidence of sludging, it is advisable to clean the
system prior to treatment in order to remove any
sludge and reduce the likelihood of these
deposits damaging new components.
•When fitting new systems flux will be evident
within the system, which can lead to damage of
system components.
•All systems must be thoroughly drained and
flushed out. The recommended flushing and
cleansing agents are Betz-Dearborn Sentinel
X300 or X400 and Fernox Superfloc Universal
Cleanser which should be used following the
flushing agent manufacturer’s instructions.
•System additives - corrosion inhibitors and
flushing agents/descalers should be suitable for
aluminium and comply to BS7593 requirements.
The only system additives recommended are
Betz-Dearborn Sentinel X100 and Fernox-Copal
which should be used following the inhibitor
manufacturer’s instructions.
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 manufacturer’s instructions. (Test kits
are available from inhibitor stockists.)
•For information or advice regarding any of the
above contact the Technical Enquiries.
Boiler
No demand
for hot water
Central
heating
load
All TRV’s shut down
(boiler flow switch
causes pump to stop)
Live feed
to pump
Switch live from
programmer, etc.
S/L N P/F
Fig. A Wiring to the pump feed connection of boiler
Fig. B Providing a 3 l/min bypass
Boiler
No demand
for hot water
Central
heating
load
All TRV’s shut down
(pump continues
around bypass)
Switch live from
programmer,
room stat, etc.
S/L
junction
S/L N P/F 3 l/min
bypass
Boiler
Connections
Boiler
Connections
NOTE: This boiler does not require a bypass.
This boiler does not require a permanent live.
These diagrams only refer to pump protection for fully TRV’d systems.