Main Combi 24 HE Instruction Manual

User’s Guide and
Important Warranty Information
Combi 24
This is a Wall Mounted Combination 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 0051.
Product/Production certified by:
Notified Body 0086.
For use in GB/IE only.
Please read this
document and keep it safe.
It will help you out should
your boiler need attention.

2
Where fitted, user label for
optional timer to be applied here.
Dear User
Thank you for choosing a Main Combination boiler. The following
instructions are simple basic steps that you can take to ensure
years of trouble free heating and hot water for your home.
Points to note
This is a gas fired, room sealed, powered flue combination boiler,
providing central heating for your home and mains fed domestic
hot water to taps and shower. It is fully automatic and does not
have a pilot light.
Priority is given to the hot water mode - when a hot water tap is
turned on the supply of heat to the central heating circuit is
interrupted.
Warranty
heateam the service division of Baxi Potterton provide a 12
month free warranty for your peace of mind. Once your boiler is
registered with us and in the unlikely event your boiler develops
a fault and your installer is unable to assist, heateam will provide
a free service to you provided the boiler is under 15 months
old. Otherwise heateam will offer a competitive fixed price repair
rate including parts, labour and VAT. To arrange an engineer
visit either in warranty or out, please call heateam on 08701 655
644. It would help if you had your boiler serial number when you
call, the serial number is shown on the back cover of this guide.
Annual Service
To ensure you receive the maximum efficiency from your boiler
we recommend your boiler has an annual service so you and
your family can continue to enjoy heating and hot water comfort.
To arrange an annual service from one of our Baxi Potterton
heating experts, please call heateam on 08701 655 644 to
arrange a visit convenient to you.
Benchmark Commissioning Check List
Please ensure that your installer hands you the boiler Installation
& Service Instructions with the “Benchmark”Commissioning
Checklist sections completed. The details in the Checklist will be
required in the event of any warranty work. Keep the instructions
in a safe place and ensure that the Service Interval Record at the
back is completed at each service visit.
12 Months Free Warranty - register today
To receive your 12 months free warranty
please complete the form supplied with the
boiler or simply call heateam, the service
division of Baxi Potterton on 08706 000 653
or visit our web site on
www.keepingbritainwarm.co.uk and
register your boiler.
Natural Gas
Main Combi 24
G.C.No47 474 01

2
1
0
4
3
bar
Reset Burner On
Flame Failure
Power On
3
Operating the Boiler
The Central Heating and Hot Water you need will
be available when the gas and electricity supplies
to the boiler are turned on with the timer and other
heating controls in your system set correctly.
Other heating controls are items such as
room thermostats, cylinder thermostats
and thermostatic radiator valves. To give
the most energy efficient performance
these controls can switch your boiler on
and off even when your timer is on.
Instructions on how to use your
programmer and other heating controls
should have been supplied with the items.
Baxi Potterton also produce a guide ‘How
to get the best out of your NEW Central
Heating System’. Telephone our Literature
Hotline on 08706 060 623 to request your
free copy.
1. Ensure that the electricity and gas supplies are
turned on. Check that the central heating pressure
is between 0.5 and 1.0 bar (Fig. 1).
2. Turn the On/Off/Reset selector switch either
anti-clockwise from the off position (Fig. 3) to both
central heating and domestic hot water or
clockwise to domestic hot water only.
3. In either position the green “power”neon ( )
will illuminate (Fig. 2).
4. Position (i) In this position the central heating
will operate according to demand or provide
domestic hot water when a tap or shower is turned
on (Fig. 4). Priority is given to domestic hot water.
5. Position (ii) In this position hot water will be
provided when a tap or shower is turned on (Fig.
5).
6. The boiler will light automatically on demand.
7. The orange “burner”neon ( ) will illuminate
when the boiler is operating and the main burner
is on (Fig. 2).
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 (if fitted) will require
resetting once the selector switch is set to
either Position (i) or Position (ii).
Reset
Reset
Position (ii)
(Hot Water)
Fig. 4
Fig. 5
Reset
OFF Position
Fig. 3
Fig. 2
Fig. 1
1. On/Off/Reset Selector Switch
2. Burner On & Fault Indicator Neon
3. Power Neon
4. Flame Failure & Fault Indicator Neon
5. Central Heating Temperature Control
6. Hot Water Temperature Control
7. Central Heating System Pressure Gauge
8. Optional Integral Timer Position
12 34 5 6 7 8
2
1
0
4
3
bar
Position (i)
(Central Heating or Hot Water)

4
Fault Indication
1. Your Main Combi 24 HE has three neon
indicators. The upper two function as boiler on and
fault indicators.
2. Depending on the nature of the fault the upper two
neons will illuminate, go off or flash.
3. There are five possible combinations, each
indicating one or more fault conditions. These are
described below.
A
The flue or flue terminal is blocked or obstructed in
some way, or there is an internal fault.
If there is no external blockage of the flue that can be
easily removed contact your Installer or Service
Engineer.
B
The circulating pump is faulty or the system pressure
has dropped. Check the system pressure (see page
7). If the pressure is in the normal range a pump fault
is indicated. Contact your Installer or Service
Engineer.
C
A fault on the boiler temperature sensor is indicated.
Contact your Installer or Service Engineer.
D
The primary system or the boiler has overheated.
Allow the boiler to cool. Turn the selector switch fully
anti-clockwise against the spring pressure to the
‘Reset’position and hold for at least 2 seconds.
If this occurs repeatedly contact your Installer or
Service Engineer.
If the boiler does not relight after resetting it is
possible that the flue has overheated. Contact your
Installer or Service Engineer.
E
The burner has failed to light, or incomplete lighting
of the burner has occurred. Turn the selector switch
fully anti-clockwise against the spring pressure to the
‘Reset’position and hold for at least 2 seconds.
If this occurs repeatedly contact your Installer or
Service Engineer.
If the boiler does not relight after resetting blockage
of the condensate drain or trap has occurred.
Contact your Installer or Service Engineer.
Burner On
Flame Failure
Power On
Off
Fast Flashing (2 every second)
On
A
Burner On
Flame Failure
Power On
Off
Slow Flashing (1 every 2 seconds)
On
B
Burner On
Flame Failure
Power On
Slow Flashing (1 every 2 seconds)
Slow Flashing (1 every 2 seconds)
On
C
Burner On
Flame Failure
Power On
Slow Flashing (1 every 2 seconds)
On
On
D
Burner On
Flame Failure
Power On
Off
On
On
E
Reset
Reset Position

5
Temperature Control
1. Central Heating: The central heating hot water
flow temperature can be adjusted between 30°C
(± 5°C) minimum and 85°C (± 5°C) maximum.
2. Turn the control knob clockwise to increase the
temperature (Fig. 6).
3. In normal winter usage we recommend that the
central heating temperature be set at maximum.
4. Domestic Hot Water: The temperature of the
domestic hot water can be adjusted by turning the
control knob clockwise to increase up to a
maximum of 65°C (Fig. 7).
5. The temperature of the water is also dependent
on the water flow rate and the temperature of the
mains water coming into the house.
6. By slightly reducing the flow from the tap the
temperature will increase up to the maximum if
required.
7. The flow rate can be reduced down to as low as
2.5 litre/min. The boiler will still recognise the need
to heat the water.
Domestic Hot Water
Temperature Control
Fig. 6
Central Heating
Temperature Control
Fig. 7

6
Central Heating System Pressure
1. The water pressure in the central heating
system is indicated by the pressure gauge.
2. With the system cold and the boiler not
operating the pressure should be between 0.5 and
1.0 bar. During operation the pressure should not
exceed 2.5 bar, and will normally be between 1.0
and 2.0 (Figs. 8 & 9).
3. A pressure of 3 or greater indicates a fault. The
safety pressure relief valve will operate, at a
pressure of 3 (Fig. 10). It is important that your
Installer or Service Engineer is contacted as
soon as possible.
4. The minimum pressure for correct operation is
0.5. If the pressure falls below 0.5, this may
indicate a leak on the central heating system (Fig.
11).
To Shut Off the Boiler
1. For short periods: Turn the selector switch to
the OFF position (Fig. 12).
2. For long periods: Turn off the selector switch
(Fig. 12), electricity and gas supplies.
If your home is to be left unoccupied for long
periods during cold weather the boiler and
whole system should be drained unless
equipped with frost protection.
3. Your installer will advise you about frost
protection and draining the system.
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 (if fitted) will require
resetting once the selector switch is set to
either Position (i) or Position (ii).
2
1
0
4
3
bar
2
1
0
4
3
bar
2
1
0
4
3
bar
2
1
0
4
3
bar
ON/OFF/RESET
Selector Switch
Reset
OFF Position
Fig. 12
Normal Pressure (when cold)
Normal Pressure (operating)
Fig. 8
Fault
Fig. 9
Below Minimum
Fig. 10
Fig. 11
Pressure Gauge

7
Servicing and Repair of your Boiler
heateam can service and repair your boiler if your
installer is not able to.
Our Baxi Potterton trained heating experts will
quickly get your heating and hot water working
again. If your boiler is out of its free 12 month
period, heateam can provide a competitive fixed
price repair rate including parts, labour and VAT.
To find out more call heateam on 08701 655 644,
open Monday to Friday 8am - 6pm, weekend
8.30am - 2pm. An appointment convenient for you
can be arranged. It would help if you had your
boiler serial number when you call, the serial
number is shown on the back cover of this guide.
Cleaning the Outer case
The painted panels should be wiped with a damp
cloth and then dried completely.

8
For your Safety
This appliance must have been installed in
accordance with the manufacturer’s instructions and
the regulations in force.
Any modification 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.
Your boiler must not be operated without the casing
correctly fitted and forming an adequate seal.
Do not interfere with any sealed components on this
boiler.
Take note of any warning labels on your boiler.
Your boiler should have the following minimum
clearances for Safety and Maintenance.
Top - 200mm
Bottom - 200mm
Both sides - 5mm
Front - 5mm (In Operation)
- 450mm (For Servicing)
If your boiler is installed in a compartment, do not
use it for storage purposes. Do not obstruct any
purpose provided ventilation openings.
Flammable materials must not be stored in close
proximity to your boiler.
Avoid skin contact when your boiler is in operation,
as some surfaces may get hot i.e. sight glass,
pipework
Ensure that the flue terminal, outside the house,
does not become damaged or obstructed,
particularly by foliage.
GB - Heating Industry definition meaning England,
Scotland, Wales, Northern Ireland, Isle of Man and
the Channel Isles

9
Fig. 13
Fig. 14
2
1
0
4
3
bar
Reset Burner On
Flame Failure
PowerOn
200mm Min
780mm
450mm
200mm Min
5mm Min
5mm Min
8mm Min
450mm Min
For Servicing
Purposes
In Operation

10
No Heating/Hot Water
User to check
fault diagnosis
Contact your installer
Installer unable
to rectify fault
Contact heateam
Important information
you need to arrange
an appointment:
- Product serial number
- Make and model
- Installer details
- Proof of purchase
Contact
heateam
08706 096 096
Installer contacts
Help-line
In the unlikely event you have a problem with
your boiler please check the following.
1. Is the electricity supply to your boiler switched on
and the selector switch set to Central Heating and
Hot Water?
If so the Green ‘Power On’neon will be on.
2. Is a fault suggested by the neon indicators?
Yes - Identify as described on Page 4.
No - Continue below
3. Is the gas supply turned on?
4. Is the mains water supply turned on?
5. Is the system pressure correct?
6. Is the programmer or timer switch set to On?
Refer to the instruction booklet supplied with
these items for correct setting and operation.
7. Are the temperature controls on the boiler turned
on and set high enough?
8. Are all system controls such as room and cylinder
thermostats set high enough?
9. Are the thermostatic radiator valves set high
enough?
Contact your Installer
If you have followed the steps in this simple checklist
but your boiler still does not fire contact your installer.
Any repairs to the boiler will usually be the
responsibility of the Installer during the warranty
period.
Installer Help-line
Should your installer need assistance he/she can
contact our trade support help-line for diagnostic and
remedy advice.

11
If you smell gas
Turn off the gas supply at the meter and call your
gas supplier immediately. It is possible to isolate the
boiler and at the isolating valve (Fig. 15).
In GB, Transco operate a 24 hour emergency
service and the telephone number will be listed in
your telephone directory.
Faulty boiler
If it is known or suspected that a fault exists
on the boiler, it must not be used until the fault
has been corrected by a competent person.
Warning !
In an Emergency
If a water or gas leak occurs or is suspected, the
boiler can be isolated at the inlet valves as follows;
1. Turn off the electrical supply and turn the selector
switch on the facia box to the OFF position.
2. Using a suitable open ended spanner or
screwdriver turn the square on the gas tap to the
left to isolate the gas supply at the boiler (Fig. 15).
3. The isolating valves are positioned under the
boiler and can be closed by turning their taps to the
right towards the wall (Fig. 16).
4. Call your Installer or Service Engineer as soon as
possible.
Gas Tap
Heating Flow, Heating
Return and Mains
Water Inlet
Isolating Valves
Fig. 15
Fig. 16

BAXI POTTERTON
A Trading Division of Baxi Heating UK Ltd
Brownedge Road Bamber Bridge Preston Lancashire PR5 6UP
After Sales Service 08701 655 644 Technical Enquiries 08706 049 049
Website www.baxipotterton.co.uk
company
Publication No. 5115811 - Iss. 2 (05/2005)
Serial Number
Date of Installation
Installer Details (name, address and contact number(s)
Please complete the boxes below
heateam
heateam is the national customer service division of
Baxi Potterton providing a free warranty service within
12 months of installation of your boiler. If your installer is
unable to rectify your boiler fault, by contacting one of
our friendly advisors we can arrange an engineer if
required.
When calling heateam it would be helpful if you could
have the following information to hand:
1 boiler serial number.
2 boiler make and model number.
3 Your installer name and address details.
4 Proof of purchase (if you do not have the
boiler serial number).
heateam will verify the boiler age via the serial number
and offer a free warranty service within 12 months of
installation of the boiler. If you are unable to provide this
information or the boiler has been installed for over 15
months, heateam will charge a competitive rate for the
repair. The engineer when visiting will verify if the boiler
is under the free 12 months warranty service, in this
case heateam will provide a full refund.
If you have contacted your installer and they are unable
to assist you at this time, please contact heateam.
heateam is open Monday to Friday 8am - 6pm,
weekend 8.30am - 2pm.
Telephone [phone]*
* To aid in continuous improvement and staff training, calls
to this line may be monitored or recorded.