Baxi Main Combi 25 Eco Instruction Manual

© Baxi Heating UK Ltd 2010
User’s Guide and
Important Warranty Information
Combi Eco
Range
Please keep these instructions in a safe place.
If you move house, please hand them over to the next occupier.

2© Baxi Heating UK Ltd 2010
Natural Gas
Main Combi 25 Eco
G.C.No47 467 01
Main Combi 30 Eco
G.C.No47 467 03
© Baxi Heating UK Ltd 2010 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,
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.
1.0 Quick Reference Guide 3
2.0 Troubleshooting 4
3.0 Repressurising System 6
4.0 ‘Intelligent Pre-heat’ Feature 7
5.0 Clearances 8
6.0 Care of the Boiler 9
7.0 Legislation 10
8.0 Emergency 11
9.0 Warranty & Service 12
Section Page
Contents
Boiler Controls - see opposite page
for Operating Quick Reference Guide
The Benchmark Scheme
Baxi Heating UK Ltd is a licensed member of the Benchmark Scheme which aims
to improve the standards of installation and commissioning of domestic heating
and hot water systems in the UK and to encourage regular servicing to optimise
safety, efficiency and performance.
Benchmark is managed and promoted by the Heating and Hotwater Industry
Council. For more information visit www.centralheating.co.uk
0086
ISO 9001
FM 00866

1.0 Quick Reference Guide
3
© Baxi Heating UK Ltd 2010
Reset
bar
0
1
2
3
4
Reset
bar
0
1
2
3
4
ON/OFF/Reset
Selector Switch
Display Central Heating
Temperature Control
Domestic Hot Water
Temperature Control
& Pre-heat Selector
System Pressure Gauge
OFF Position
The boiler will not operate.
Central Heating Temperature Control
Turn the knob clockwise to increase or anticlockwise to decrease the temperature.
Range 25 - 80° C.
Domestic Hot Water Temperature Control & Pre-heat Selector
Turn the knob clockwise to increase or anticlockwise to decrease the temperature.
Range 40 - 60° C. It also activates the ‘Intelligent Pre-heat’ feature - see Section 4.0.
Central Heating Indicator - The indicator will illuminate when the boiler is in the central
heating mode.
Domestic Hot Water Indicator - The indicator will illuminate when hot water is being
supplied to a tap or shower.
Burner On Indicator - The indicator will illuminate when the burner has fired and is heating
your central heating or domestic hot water.
Boiler Output Temperature - In either the central heating or domestic hot water position
the display will illuminate showing the current boiler temperature in degrees centigrade.
Central Heating System Pressure - The normal operating water pressure is shown when the
needle is in the GREEN section of the gauge, between 1 and 2.5 bar. If the pressure exceeds 3
bar (needle in the RED section) the safety pressure valve will operate and a fault is indicated.
Contact your Installer.
Reset
Reset
Central Heating & Hot Water
Both Heating & Hot Water will operate.
Reset
Hold for approx 5 seconds and release.
Display
Position of
Optional Timer
Reset
Domestic Hot Water
Hot Water will operate.

2.0 Troubleshooting
4© Baxi Heating UK Ltd 2010
START
Make sure the gas supply is
turned ON and check if other
gas appliances are operating
(e.g. fire, cooker).
If no gas, consult your
supplier.
Is the ON/OFF/Reset
Select Switch in the
( ) position and
the display lit ?
Is the ( ) or ( ) light on
and the ( ) on ?
Check electricity to the
boiler is switched on.
Reset
Display
Central Heating
Indicator Domestic Hot
Water Indicator
Burner On
Indicator
Boiler operating satisfactorily.
bar
0
1
2
3
4
Is the Central Heating System
Pressure needle in the GREEN
section, between 1 and 2.5 bar ?
If the reading falls below 1 bar
repressurise the system as
described in section 3.1.
Does the display show an error
code e.g. E133, E110 ?
Boiler not working
NO
NO
YES YES
YES
NO
Turn the ON/OFF/Reset
Selector Switch to Reset.
Reset
Error Code E119 showing low
pressure.
NO
YES
YES
NO
If boiler does not
Reset

2.0 Troubleshooting
5
© Baxi Heating UK Ltd 2010
Is the Timer ON and calling for
heat ?
Ensure timer is set for Central
Heating ON (see any
instructions supplied with
timer).
Is the Room Thermostat (if
fitted) set high enough ?
15
10
5
20
25
15
10
5
20
25
Turn Room Thermostat to
maximum setting (typical
example shown).
If you don’t know what you need to do to
get the boiler to light, or need help with
the system and controls, contact your
installer as soon as possible.
YES
NO
CONTACT YOUR
INSTALLER OR
SERVICE ENGINEER.
YES
12
1
2
3
4
5
6
7
8
9
10
11
CH ON CH OFF
Typical
examples of
external timer
NO

3.0 Repressurising System
6© Baxi Heating UK Ltd 2010
bar
0
1
2
3
4
bar
0
1
2
3
4
3.1 Central Heating System Pressure
1. The normal operating water pressure is when the
needle is in the GREEN section of the gauge, between 1
and 2.5 bar (Fig. 1). If the pressure exceeds 3 bar (needle
in the RED section) the safety pressure valve will operate
and a fault is indicated. Contact your installer.
2. It may be necessary to repressurise the system
occasionally (Fig. 2). The needle will be in the lower RED
section of the gauge, between 0 and 0.5.
3.A filling device (the filling loop) will be fitted on the
system. This will be on the boiler itself (Fig. 3), or on
pipework near to the boiler.
4. If you are unsure of its position, or cannot identify it,
consult the installer who fitted the boiler.
5. The filling loop consists of two taps and a separate
flexible pipe with connection fittings.
6. Only when repressurising should the flexible pipe be
connected between the two taps. Ensure that the nuts
on the pipe ends are tightened onto the taps.
7. Fully open one of the taps first, and then while
watching the pressure gauge, carefully open the second
tap.
8. When the needle on the gauge is indicating 1 or more,
in the green section of the gauge, turn both taps off.
9. Disconnect the flexible pipe from the taps (a small
amount of water may be present) and remove it. Keep
the pipe in a safe place for future use.
Fig. 1
Fig. 2
Normal Pressure
Requires
Repressurising
Flexible Hose
Taps
Fig. 3

4.0 ‘Intelligent Pre-heat’ Feature
7
© Baxi Heating UK Ltd 2010
Operation of Pre-heat
1. The boiler incorporates an intelligent pre-heat feature
that will ensure optimum domestic hot water
performance.
2. This features ‘learns’ the domestic hot water demand,
and pre-heats the boiler primary circuit (main heat
exchanger, pipework within the boiler case and
domestic hot water heat exchanger) in anticipation of
further demand at the same time on the next day.
3. The feature works on a 24 hour basis. If for example
there is a demand for hot water at 7:00 AM on Monday,
the pre-heat will operate at 6:50 AM on Tuesday for 1
hour. Similarly if there is a demand at 9:25 PM, the pre-
heat will operate at 9:15 PM the next day, again for 1
hour.
4. If on Tuesday at 7:00 AM there is no hot water
demand there will be no pre-heat on Wednesday at this
time.
5. The feature also operates for one hour after each
demand to maintain the temperature of the boiler.
6. There can be up to 24 pre-heat operations in a 24
hour period. While operating in the pre-heat mode the
boiler will fire up briefly 3 or 4 times in the hour to
maintain the boiler at temperature.
7. During the pre-heat period the domestic hot water
indicator will flash (Fig. 6).
8. The pre-heat feature will not operate if the DHW
Temperature Control is turned fully anticlockwise
(Fig. 4). In this position the boiler will operate as a
conventional combination boiler, providing hot water at
50° C.
9. Once the Temperature Control is turned
approximately 30° clockwise (Fig. 5) the pre-heat
feature is activated.
10. Bewteen 30° and fully clockwise the hot water
temperature can be altered from 40° and 60° C.
30°
Fig. 4
Fig. 5
Pre-heat Off
Pre-heat Activated
Fig. 6
4.1

5.0 Clearances
8© Baxi Heating UK Ltd 2010
Fig. 7
Fig. 8
200mm Min
800mm
450mm
5mm Min
5mm Min
450mm Min
For Servicing
Purposes
In Operation
5mm Min 5.1 For your Safety
1. This appliance must have been installed in accordance
with the manufacturer’s instructions and the regulations
in force.
2. 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.
3. Your boiler must not be operated without the casing
correctly fitted.
4. Do not interfere with any sealed components on this
boiler.
5. Take note of any warning labels on your boiler.
6. Your boiler should have the following minimum
clearances for Safety and Maintenance (Figs. 7 & 8):-
Top - 200mm
(300mm for 80/125mm flueing system)
Bottom - 200mm
Left side - 5mm
Right Side - 5mm
Front - 5mm (In Operation)
- 450mm (For Servicing)
7. If your boiler is installed in a compartment, do not use
it for storage purposes. Do not obstruct any purpose
provided ventilation openings.
8. Flammable materials must not be stored in close
proximity to your boiler.
9. Avoid skin contact when your boiler is in operation, as
some surfaces may get hot e.g. pipework.
10. Ensure that the flue terminal, outside the house,
does not become damaged or obstructed, particularly
by foliage.
11. It is important that the condensate drain system is
not blocked, modified or damaged in any way as this
would affect the operation of your boiler. Your installer
should have insulated any exposed pipework.
GB - Heating Industry definition meaning England, Scotland,
Wales, Northern Ireland, Isle of Man and the Channel Isles
200mm Min
(300mm Min if
using 80/125mm
flueing system)
At least 1.5°

6.0 Care of the Boiler
9
© Baxi Heating UK Ltd 2010
6.1 Cleaning the Outer case
The painted panels should be wiped with a damp cloth and
then dried completely. DO NOT USE ABRASIVE
CLEANING AGENTS.
6.2 Protection & Precaution
1. The boiler incorporates an integral frost protection feature
that will operate in both modes. If the boiler temperature falls
below 5° C, then the boiler will operate until the water
temperature has been raised.
2. If a system frost thermostat has been fitted (your installer
will be able to advise you), then to operate correctly and
protect your system, the gas and electricity must be left on and
the appliance set in the central heating mode.
3. The boiler incorporates an integral pump protection feature
which continually monitors the time since the pump last
operated. To prevent seizure, the pump will operate for
approximately 1 minute if it has not run in the last 24 hours.
6.3 Fault Indication
1. If a fault occurs on the boiler an error code may be shown
on the facia display (Fig. 9).
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'.
3. E20, E28, E50 & E160 indicate faulty components. You
should make a note of the displayed error code and contact
your installer or service engineer.
4. If E110 is displayed overheat of the primary water or flue
system has occurred. Turn the selector switch to the reset
position and hold for at least 5 seconds. If the boiler does not
relight, or the code is displayed regularly contact your installer
or service engineer.
5. E119 is displayed when the primary water pressure is less
than 0.5 bar. After repressurising the system the boiler should
operate. Your installer will be able to advise you about the
method of repressurising. See page 6 for further details.
6. E133 indicates that the gas supply has been interrupted,
ignition has failed or the flame has not been detected. Ensure
that the gas supply has not been turned off, and turn the
selector switch to the reset position and hold for at least 5
seconds. If the boiler does not relight, or the code is displayed
regularly contact your installer or service engineer.
Central Heating NTC Fault
PCB Fault
Hot Water NTC Fault
Safety Thermostat Operated
Water Pressure Switch Not Operated
Interruption Of Gas Supply or Flame Failure
Fan or Fan Wiring Fault
E20
E28
E50
E110
E119
E133
E160
Table of Error Codes
Reset
bar
0
1
2
3
4
Display
Then
Fig. 9

7.0 Legislation
10 © Baxi Heating UK Ltd 2010
7.1 Installation, Commissioning, Service & Repair
1. This appliance must be install in accordance with the
manufacturer’s instructions and the regulations in force. Read
the instructions fully before installing or using the appliance.
2. In GB, this must be carried out by a competent person as
stated in the Gas Safety (Installation & Use) Regulations.
3. 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.
4. In IE (Eire), this must be carried out by a competent person
as stated in I.S. 813 “Domestic Gas Installations”.
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
The boiler meets the requirements of Statutory Instrument
“The Boiler (Efficiency) Regulations 1993 No 3083” 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 Bodies 0086.
For GB/IE only.
7.2 Benchmark Commissioning Checklist
1. Please ensure that the installer has fully completed the
Benchmark Checklist on the inside back pages of the
installation instructions supplied with the product and that you
have signed it to say that you have received a full and clear
explanation of its operation. The installer is legally required to
complete a commissioning checklist as a means of complying
with the appropriate Building Regulations (England and Wales).
2. All installations must be notified to Local Area Building
Control either directly or through a Competent Persons
Scheme. A Building Regulations Compliance Certificate will
then be issued to the customer who should, on receipt, write
the Notification Number on the Benchmark Checklist.
3. This product should be serviced regularly to optimise its
safety, efficiency and performance. The service engineer should
complete the relevant Service Record on the Benchmark
Checklist after each service.
4. The Benchmark Checklist may be required in the event of
any warranty work and as supporting documentation relating
to home improvements in the optional documents section of
the Home Information Pack.