Baxi COMBI INSTANT 105e Operation instructions

Baxi Combi Instant 105e
Gas Fired Wall Mounted Combination Boiler
User’s Operating
Instructions
Please keep these instructions safe.
Should you move house, please hand
them over to the next occupier.

2
Baxi UK Limited is one of the leading manufacturers
of domestic heating products in the UK.
Our first priority is to give a high quality service to our
customers. Quality is designed into every Baxi product
- products which fulfil the demands and needs of
customers, offering choice, efficiency and reliability.
To keep ahead of changing trends, we have made a
commitment to develop new ideas using the
latest technology - with the aim of continuing to
make the products that customers want to buy.
Everyone who works at Baxi has a commitment to
quality because we know that satisfied customers
mean continued success.
We hope you get a satisfactory service from Baxi. If
not, please let us know.
Natural Gas
Baxi Combi Instant 105e
G.C.No47 075 09
Baxi is a BS-EN ISO 9001
Accredited Company
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 0051.
For GB/IE only.

1.0 Warnings
3
1.1 Safe Installation
1. The appliance is suitable for installation only in
G.B. and I.E. and should be installed in
accordance with the rules in force. For Ireland
install in accordance with I.S.813 “INSTALLATION
OF GAS APPLIANCES”. The installation must be
carried out by a CORGI Registered Installer or
other registered competent person and be in
accordance with the relevant requirements of GAS
SAFETY (Installation and Use) REGULATIONS most
recent edition, the BUILDING REGULATIONS issued
by the Department of the Environment, BUILDING
STANDARDS (Scotland) (Consolidation)
REGULATIONS issued by the Scottish Development
Department and the LOCAL BUILDING
REGULATIONS.Where no specific instructions are
given, reference should be made to the relevant
BRITISH STANDARD CODES OF PRACTICE
and INSTALLATION SPECIFICATIONS.
2. This appliance must be installed in
accordance with the manufacturer’s
instructions and the rules in force, and only
used in a suitably ventilated location.
3. Read the instructions before installing or
using this appliance.
4. Any purpose provided ventilation should be
checked periodically to ensure that it is free from
obstruction.
IMPORTANT - The addition of anything that
may interfere with the normal operation of the
appliance without the express written
permission of Baxi UK Limited could invalidate
the appliance warranty and infringe the GAS
SAFETY (Installation and Use) REGULATIONS.
1.2 In case of gas leaks
1. If a gas leak is found or suspected, turn off the
gas supply at the meter immediately and at the
isolating valve on the boiler if possible. Contact
your Installer or Transco (under 'Gas' in the
phone directory).
1.3 Servicing your Appliance
1. For reasons of safety and economy your
appliance should be serviced annually. Servicing
must be performed by a competent person. Your
Installer or British Gas Service will be able to
advise you.
1.4 Electricity Supply
1. THIS APPLIANCE MUST BE EARTHED.
2. A standard 230V ~ 50Hz supply is required.
The appliance must be protected by a 3 amp
fuse.
Never Hang Flammable Items Over The
Appliance
STANDARD
B.S. 6891
B.S. 5440: Pt 1
B.S. 5440: Pt 2
B.S. 5546
B.S. 7074
B.S. 5449
B.S. 6798
SCOPE
Gas Installation.
Flues.
Air Supply.
Installation of hot water supplies
for domestic purposes.
Expansion vessels and ancillary
equipment for sealed water systems.
Forced circulation hot water systems.
Installation of gas fired hot water
boilers.
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. 1).
3. The isolating valves are positioned under the boiler and can be
closed by turning their taps to the right towards the wall (Fig. 2).
4. Call your Service Engineer as soon as possible.
“Benchmark”Installation, Commissioning and Service
Record Log Book
Please ensure that your installer has completed the Installation
and Commissioning sections of the Log Book and hands the Log
Book over. The details of the Log Book will be required in the
event of any warranty work. Keep the Log Book in a safe place
and ensure that the relevant sections are completed at each
subsequent regular service visit.
Gas Tap
Heating Flow, Heating Return
and Mains Water Inlet
Isolating Valves
Fig. 1
Fig. 2
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 01256 372300 or writing to:-
1 Elmwood,
Chineham Business Park,
Crockford Lane,
Basingstoke.
RG24 8WG.

2.0 Introduction
4
2.1 Introduction
1. Your Baxi Combi Instant 105e 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.
2. 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.
2.2 Instant Domestic Hot Water
1. The boiler expansion vessel incorporates a
small volume of stored primary hot water.
2. When the boiler has been off and there is then a
demand for domestic hot water the stored primary
hot water ensures that domestic hot water is
supplied instantly at temperature.
3. The stored hot water is part of the primary
circuit. This is not supplied as domestic hot water,
which is fresh mains water heated by a heat
exchanger within the boiler.
4. The stored primary hot water temperature is
maintained whilst the boiler is in operation. During
a period when there is no demand for heating or
hot water the temperature of the stored primary hot
water will eventually fall. The boiler will operate
occasionally in order to maintain the temperature.
This is indicated by the domestic hot water mode
neon flashing (item 13 of Fig. 3).
2.3 Facia Panel
1. The facia panel is behind the hinged lower door.
As well as the on/off/reset selector switch, central
heating temperature control knob, pre-heat control
and pressure gauge, the facia incorporates ten
neon indicator lights.
2. Neons 12 to 15 indicate the operational status of
the boiler. Neons 6 to 11 have a dual function,
indicating the temperature of the central heating
water when constantly illuminated. If a fault
develops the appropriate neon will begin to flash.
Refer to Sections 3.3 to 3.7.
30°40°50°60°70°80°
2
1
0
4
3
bar
OFF
ON
PREHEAT
Fig. 3
30°40°50°60°70°80°
1. On/Off/Reset Selector Switch
2. Central Heating Temperature Control
3. Pre-Heat Control
4. Central Heating System Pressure Gauge
5. Optional Integral Timer Position
Neon Indicators
6. Flame Failure
7. Safety Thermostat Activated
8. Fault on Fan or Flue
9. Fault on Pump or Low System Pressure
10. Fault on Hot Water Sensor
11. Fault on Central Heating Sensor
12. Power On
13. Domestic Hot Water Mode
14. Central Heating Mode
15. Burner On
32145
6 7 8 9 10 11
12 13 14 15
KEY TO FACIA PANEL (Fig. 3)
When neons 6 to 11 are
constantly illuminated, they
indicate the temperature of
the central heating water.

3.0 Operating the Boiler
5
3.1 Operating the Boiler
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. 4).
2. Turn the On/Off/Reset selector switch either
anti-clockwise from the off position (Fig. 6) to both
central heating and domestic hot water or
clockwise to domestic hot water only.
3. In either position the green power on indicator
( ) will illuminate (Fig. 5).
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. 7). Priority is given to domestic hot water.
The central heating/hot water neon ( ) will
illuminate (Fig. 5). Neons 6 to 11 will illuminate as
the temperature rises.
5. Position (ii) In this position hot water will be
provided when a tap or shower is turned on
(Fig. 8). The hot water neon ( ) will illuminate
(Fig. 5).
6. The boiler will light automatically on demand.
7. The orange burner on neon ( ) will illuminate
when the boiler is operating and the main burner is
on (Fig. 5).
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).
30°40°50°60°70°80°
2
1
0
4
3
bar
OFF
ON
PREHEAT
Position (ii)
(Hot Water)
Fig. 7
Fig. 8
OFF Position
Fig. 6
Fig. 5
Fig. 4
2
1
0
4
3
bar
Power On
Neon Burner On
Neon
Central Heating
System Pressure
Gauge
Position (i)
(Central Heating or Hot Water)
On/Off/Reset
Selector Switch
Central
Heating Neon
Domestic
Hot Water
Neon
30°40°50°60°70°80°
6 7 8 9 10 11

3.0 Operating the Boiler
6
3.2 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. 9).
3. In normal winter usage we recommend that the
central heating temperature be set at maximum.
4. Domestic Hot Water Pre-Heat: To enjoy
optimum performance of the boiler the pre-heat
control should be set fully clockwise to the ON
position (Fig. 10). When there is a demand for hot
water it will be supplied at approximately 65°C
instantaneously.
5. Turning the control 15°clockwise from the OFF
position will activate the pre-heat feature. Hot
water will be supplied at approximately 35°C
instantaneously.
6. To increase the temperature turn the control
further clockwise. For example, when set 90°
clockwise the boiler will supply hot water at
approximately 44°C instantaneously. At a
position 180°from clockwise (i.e. straight down)
the hot water will be supplied at 52°C
instantaneously.
7. When the control is set anywhere between 15°
clockwise from the OFF position and the ON
position, the pre-heat feature will operate.
8. With the control in the OFF position (Fig. 11)
the pre-heat feature will not operate. Hot water
will be supplied at approximately 50°C.
9. The pre-heat feature will function with the
selector switch in either operating position. This is
indicated by the domestic hot water mode neon
flashing (Fig. 12).
10. 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.
3.3 Flame Failure Reset
1. The red flame failure neon ( ) will illuminate in
the event of the burner failing to light, or when
incomplete lighting of the burner occurs (Fig. 12).
2. Turn the selector switch fully anti-clockwise
against the spring pressure to the reset position
(R) and release (Fig. 13). Set the selector to the
required position to light the boiler.
3. If the flame failure light illuminates repeatedly a
fault is indicated. Your Service Engineer should
be contacted as soon as possible.
OFF
ON
PREHEAT
Domestic Hot Water
Pre-Heat Control
ON Position
Fig. 9
Central Heating
Temperature Control
Fig. 10
Reset Position
Fig. 13
30°40°50°60°70°80°
Flame Failure
Neon
Fig. 12
OFF
ON
PREHEAT
Fig. 11
Domestic Hot Water
Pre-Heat Control
OFF Position
Domestic Hot
Water Neon

3.0 Operating the Boiler
7
3.4 Safety Thermostat
1. Your Baxi Combi Instant 105e is fitted with an
additional safety device, which shuts down the
boiler in the event of the system or the boiler
overheating. The safety thermostat neon ( ) will
light in this instance (Fig. 14).
2. To reset: Turn the selector fully anti-clockwise
against the spring pressure to the reset position
(R) and release (Fig. 15). Set the selector to the
required position to light the boiler.
3. If the safety thermostat operates repeatedly,
causing boiler shutdown, a fault is indicated. Your
Service Engineer should be contacted as soon as
possible.
3.5 Air Flow Monitor
1. The boiler is fitted with an air pressure sensing
device. This monitors the flue system.
2. If the neon illuminates ( ) it indicates that
the flue or flue terminal is blocked or obstructed in
some way, or that there is an internal fault. If there
is no external blockage of the flue terminal that
can be easily removed contact your Service
Engineer (Fig. 14).
3.6 Pump Fault or Low Pressure
1. The neon ( ) will illuminate if the circulating
pump is faulty or the system pressure drops
below the minimum requirement (Fig. 14).
2. Check the pressure gauge as described in
Section 3.9. If the pressure is in the normal range,
a pump fault is indicated. Contact your Service
Engineer to determine the nature of the fault.
3.7 Sensor Fault
1. When the ( ) or ( ) neon is illuminated a
fault on the hot water or central heating
temperature sensor is indicated (Fig. 14). Contact
your Service Engineer.
3.8 Pump Protection
1. With the selector switch in either Position (i) or
Position (ii) (Figs. 16 & 17) the pump will
automatically operate for 1 minute in every 24
hours to prevent sticking.
30°40°50°60°70°80°
Air Flow
Monitor Neon
Pump/Low
Pressure Neon
Sensor Fault
Neons
Fig. 14
Fig. 16
Fig. 17
Safety
Thermostat
Neon
Reset Position
Fig. 15

3.0 Operating the Boiler
8
3.9 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. 18 & 19).
3. A pressure of 3 or greater indicates a fault.
The safety pressure relief valve will operate, at a
pressure of 3 (Fig. 20). It is important that your
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. 21).
5. The system must be re-pressurised by your
Service Engineer.
3.10 To Shut Off the Boiler
1. For short periods: Turn the selector switch to
the OFF position (Fig. 22).
2. For long periods: Turn off the selector switch
(Fig. 22), 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 there
is additional 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).
3.11 Frost Protection Mode
1. The frost protection feature will operate when
the selector switch is in the central heating and
domestic hot water mode.
The gas and electrical supplies to the boiler must
be on and the system pressure must be within
the range described in Section 3.9.
2. If the system temperature falls below 5°C, then
the boiler will fire until the water temperature has
been raised.
3. Further frost protection can be incorporated by
using a frost thermostat to protect the whole
system.
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
Selector Switch
OFF Position
Fig. 22
Normal Pressure (when cold)
Normal Pressure (operating)
Fig. 18
Fault
Fig. 19
Below Minimum
Fig. 20
Fig. 21
Pressure Gauge

4.0 Clearances and Check List
9
4.1 Clearances around the Boiler
(Figs. 23 & 24)
1. The minimum clear spaces needed around
the boiler measured from the casing are as
follows:
Top - 200mm
Bottom - 200mm
Both sides - 5mm
Front - 5mm (In Operation)
- 450mm (For Servicing)
2. These areas must not be obstructed in any
way. Blocking the clearance spaces may
result in the boiler overheating and damage
may occur.
3. The gas burning compartment of your boiler is
completely sealed from the room in which it is
fitted. Products from the combustion of gas are
vented to the outside through the flue terminal
which must be kept free from obstruction as this
would interfere with the correct operation of the
boiler.
4. The boiler may be installed in a cupboard if
these minimum clearances are kept. The
compartment should be large enough to house
the boiler and ancillary equipment only.
5. IT SHOULD NOT BE USED AS A STORAGE
CUPBOARD.
4.2 Check List
1. If a fault develops, or is suspected, call your
Service Engineer as soon as possible.
2. Go through the following check list before you
make contact.
a) Is the electricity supply on ?
b) Is the selector switch on (giving a green
“Power ON”neon) and set for both Central
Heating and Domestic Hot Water ?
c) Is the red “Flame Failure”neon lit ?
Turn the On/Off/Reset selector fully anti-
clockwise.
d) Is the gas supply on ?
e) Is the mains water supply turned on ?
f) Is the system pressure correct ?
g) Are the boiler temperature controls set high
enough ?
h) Is the time clock (if fitted) calling for central
heating ?
i) Is the room thermostat (if fitted) set high
enough ?
j) Are the radiator valves open ?
200mm Min
780mm
450mm
200mm Min
5mm Min
5mm Min
5mm
450mm Min
For Servicing
Purposes
Fig. 23
Fig. 24
In Operation

5.0 Cleaning, Spares & Guarantee
10
5.1 Cleaning the Outercase
The painted panels should be wiped with a damp
cloth and then dried completely. DO NOT USE
ABRASIVE CLEANING AGENTS.
5.2 Spare Parts
IMPORTANT - Only a competent person
should be used to service or repair this boiler.
1. Any repairs to the boiler will usually be the
responsibility of the Installer during the
guarantee period after which spare parts may be
obtained through approved Baxi stockists if
required.
2. Quote the appliance name, model number
and where possible the part number when
ordering spares. A parts list is included in the
Installation and Servicing Instructions.
3. The name, model number and serial number
can be found on the information label on the
back of the hinged lower door (Fig. 25).
5.3 Guarantee
1. Your Baxi Combi Instant 105e is designed and
produced to meet all the relevant Standards.
2. Baxi UK Limited provide a 12 month
guarantee on the boiler. The guarantee operates
from the date installation is completed for the
customer who is the original user.
3. To maximise the benefit from our guarantee
we urge you to return the reply-paid guarantee
registration.
4. This does not in any way prejudice your rights
at Common Law. Such rights between the
customer and the installer or supplier from whom
the unit was purchased remain intact.
Any component or part which becomes
defective during the guarantee period as a
result of faulty workmanship or material
whilst in normal use will be repaired or
replaced free of charge.
Information Label
Fig. 25

11
Baxi UK Limited manufacture a comprehensive range
of products for the domestic heating market.
Gas Central Heating Boilers
(Wall, Floor and Fireside models).
Independent Gas Fires.
Renewal Firefronts.
Gas Wall Heaters.
Solid Fuel Fires.
If you require information on any of these products,
please write, telephone or fax to the Sales Department.

Baxi UK Limited
Brownedge Road
Bamber Bridge Preston
Lancashire
PR5 6SN
www.baxi.com
After Sales Service
08706 096 096
Comp No248742 - Iss 1 - 2/01
921.892.1