Baxi BAXI COMBI INSTANT 105 HE Operation instructions

Baxi Combi Instant 80 HE
Baxi Combi Instant 105 HE
Gas Fired Wall Mounted
Condensing 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 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 80 HE
G C No47 075 17
Baxi Combi Instant 105 HE
G C No47 075 19
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 GB/IE only
Baxi is a BS-EN ISO 9001
Accredited Company
Where fitted, user label for
optional timer to be applied here
This product has an energy rating (B) on a scale of A to G
For more information see www boilers org uk This is a certification mark

Legislation
3
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, 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 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 Commissioning Checklist
Please ensure that your installer hands you the boiler Installation & Servicing 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
All CORGI registered installers carry a CORGI identification card and have a
registration number You can check your installer is registered by telephoning
0870 4012300 or writing to:-
1 Elmwood,
Chineham Business Park,
Crockford Lane,
Basingstoke RG24 8WG
or check online at www corgi-gas-safety com
Baxi 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.
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

1.0 Warnings
4
1.1 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 Installer or Service Engineer as soon as
possible
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 Gas Supplier
immediately
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
Service Engineer will be able to advise you
2 Any purpose provided ventilation should be checked
periodically to ensure that it is free from obstruction
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
Gas Tap
Heating Flow, Heating Return and
Mains Water Inlet
Isolating Valves
Fig. 1
Fig. 2

2.0 Introduction
5
2.1 Introduction
1 Your Baxi Combi Instant 80 HE or 105 HE is a gas
fired, room sealed, powered flue condensing 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
3 Due to the high efficiency and resultant low flue gas
temperature when in condensing mode a white plume of
condensate will be emitted from the terminal This will be
particularly evident during periods of low outside
temperature
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 panel
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
30o40o50o60o70o80o
2
1
0
4
3
bar
Reset
OFF
ON
PREHEAT
Fig. 3
30o40o50o60o70o80o
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 or Blocked Condensate Drain
7 Safety Thermostat Activated (Boiler or Flue)
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
Hinged Lower
Door Panel
Facia Panel

3.0 Operating the Boiler
6
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).
30o40o50o60o70o80o
2
1
0
4
3
bar
Reset
OFF
ON
PREHEAT
Reset
Reset
Position (ii)
(Hot Water)
Fig. 7
Fig. 8
Reset
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
30o40o50o60o70o80o
6 7 8 9 10 11

3.0 Operating the Boiler
7
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, when incomplete
lighting of the burner occurs or blockage of the
condensate drain (Fig 12)
2 Turn the selector switch fully anti-clockwise against
the spring pressure to the ‘Reset’ position for at least
two seconds 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 with either the boiler, the gas supply or the
condensate drain Your Installer or Service Engineer
should be called as soon as possible
OFF
ON
PREHEAT
Reset
Domestic Hot Water
Pre-Heat Control
ON Position
Fig. 9
Central Heating
Temperature Control
Fig. 10
Reset Position
Fig. 13
30o40o50o60o70o80o
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
8
3.4 Safety Thermostats
1 Your Baxi Combi Instant 80 HE or 105 HE is fitted
with additional safety devices, which shut down the
boiler in the event of the system, the boiler or the flue
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 for at least
two seconds and release (Fig 15) Set the selector to the
required position to light the boiler
3 If after turning the selector to the ‘Reset’ position the
boiler does not relight or the safety thermostat operates
repeatedly, causing boiler shutdown, a fault is indicated
Your Installer or 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 Installer or 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 Installer or 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 Installer or 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
30o40o50o60o70o80o
Air Flow
Monitor Neon
Pump/Low
Pressure Neon
Sensor Fault
Neons
Reset
Reset
Fig. 14
Fig. 16
Fig. 17
Safety
Thermostat
Neon
Reset
Reset Position
Fig. 15

3.0 Operating the Boiler
9
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 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 21)
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
Reset
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
10
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
Left Side - 5mm
Right Side - 20mm/5mm
Front - 5mm (In Operation)
- 450mm (For Servicing)
* NOTE: The boiler can be operated with a clearance
of 5mm at the right. This is also sufficient for routine
maintenance. However a clearance of 20mm is
required if it is necessary to remove the secondary
heat exchanger. This should be considered when siting
the appliance and in the event of any subsequent
alteration in the area of installation.
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 Installer or
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
20mm/5mm Min
see *NOTE:
5mm Min
5mm
450mm Min
For Servicing
Purposes
Fig. 23
Fig. 24
In Operation

5.0 Cleaning Spares & Guarantee
11
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 short
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 panel (see back page)
5.3 Guarantee
1 Your Baxi Combi Instant 80 HE or 105 HE is designed
and produced to meet all the relevant Standards
2 Baxi 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.

Comp No5111808 - Iss 2 - 03/05
BAXI POTTERTON
A Trading Division of Baxi Heating UK Ltd
Brownedge Road Bamber Bridge Preston Lancashire PR5 6UP
After Sales Service 08706 096 096 Technical Enquiries 08706 049 049
Website www.baxi.co.uk
company
When contacting Baxi Potterton please have the following
information to hand:
Appliance Name
Model Number
Serial Number
A label giving these details is situated on the rear of the
hinged lower door panel attached to the users operating
instruction label
Label
Lower Door
Panel
Users Operating
Instruction Label
923 611 2