Baxi 100/2 HE Plus Release note

Please leave these instructions with the user
Baxi 100/2 HE Plus
Wall Mounted Powered Flue Condensing Boiler
Gas Fired Central Heating Unit
Installation & Servicing Instructions

2
Baxi is one o the leading manu acturers o domestic
heating products in the UK.
Our irst priority is to give a high quality service to our
customers. Quality is designed into every Baxi product -
products which ul il the demands and needs o customers,
o ering choice, e iciency and reliability.
To keep ahead o changing trends, we have made a
commitment to develop new ideas using the
latest technology - with the aim o continuing to make the
products that customers want to buy.
Everyone who works at Baxi has a commitment to quality
because we know that satis ied customers mean continued
success.
We hope you get a satis actory service rom Baxi. I not,
please let us know.
Natural Gas
Baxi 100/2 HE Plus
G.C.No41 075 34
The boiler meets the requirements o Statutory Instrument “ The
Boiler (E iciency) Regulations 1993 No3083” and is deemed to
meet the requirements o Directive 92/42/EEC on the energy
e iciency requirements or new hot water boilers ired with liquid
or gaseous uels:-
Type test or purpose o Regulation 5 certi ied by:
Noti ied Body 0087.
Product/Production certi ied by:
Noti ied Body 0086.
For GB/IE only.
Baxi is a BS-EN ISO 9001
Accredited Company
This product has an energy rating (A) on a scale o A to G.
For more in ormation see www.boilers.org.uk. This is a certi ication mark.

3
0.0 Legislation 4
1.0 Introduction 5
2.0 General Layout 6
3.0 A liance O eration 7
4.0 Technical Data 8
5.0 Dimensions and Fixings 9
6.0 System Details 10
7.0 Site Requirements 14
8.0 Installation 20
9.0 Electrical 26
10.0 Commissioning the Boiler 28
11.0 Fitting the Outer Case 29
12.0 Servicing the Boiler 30
13.0 Changing Com onents 32
14.0 Short Parts List 39
15.0 Fault Finding 40
Section Page
Contents

0.0 Legislation
4
Baxi declare that no substances harmful to health
are contained in the a liance or used during
a liance manufacture.
The a liance 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 o the:
• Gas Sa ety (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 speci ic instructions are given, re erence should be
made to the relevant British Standard Code o Practice.
In IE, the installation must be carried out by a competent
Person and installed in accordance with the current edition
o I.S. 813 ‘Domestic Gas Installations’, the current Building
Regulations and re erence should be made to the current
ETCI rules or electrical installation.
All systems must be thoroughly flushed and treated
with inhibitor (see section 6.2).
IMPORTANT - Installation, Commissioning, Service & Repair
This appliance must be installed in accordance with the manu acturer’s instructions and
the regulations in orce. Read the instructions ully be ore installing or using the
appliance.
In GB, this must be carried out by a competent person as stated in the Gas Sa ety
(Installation & Use) Regulations.
Definition of com etence: A person who works or a CORGI registered company and
holding current certi icates 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 li ted and handled by two people. For recommended
hand holds see section 8.3. Stooping should be avoided and protective equipment worn
where necessary. Carrying & li ting equipment should be used as required, e.g. when
installing in a lo t space.
The addition o anything that may inter ere with the normal operation o the appliance
without express written permission rom the manu acturer or his agent could invalidate
the appliance warranty. In GB this could also in ringe the Gas Sa ety (Installation and
Use) Regulations.
Warning - Check the in ormation on the data plate is compatible with local supply
conditions.
“Benchmark”
Installation, Commissioning and Service Record Log Book
Please ensure that your installer has completed the Installation and Commissioning
sections o the Log Book and hands the Log Book over. The details o the Log Book will
be required in the event o any warranty work. Keep the Log Book in a sa e place and
ensure that the relevant sections are completed at each subsequent regular service visit.
All CORGI registered installers carry a CORGI identi ication 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,
Crock ord Lane,
Basingstoke. RG24 8WG
Codes of Practice, most recent version should be used
In GB the following Codes of Practice a ly:
Standard Sco e
BS 6891 Gas Installation.
BS 5546 Installation o hot water supplies or domestic
purposes.
BS 5449 Forced circulation hot water systems.
BS 6798 Installation o gas ired hot water boilers.
BS 5440 Part 1 Flues.
BS 5440 Part 2 Ventilation.
BS 7074 Expansion vessels and ancillary equipment or
sealed water systems.
BS 7593 Treatment o water in domestic hot water
central heating systems.
In IE the following Codes of Practice a ly:
Standard Sco e
I.S. 813 Domestic Gas Installations.
The ollowing BS standards give valuable additional in ormation;
BS 5546 Installation o hot water supplies or domestic
purposes.
BS 5449 Forced circulation hot water systems.
BS 7074 Expansion vessels and ancillary equipment or
sealed water systems.
BS 7593 Treatment o water in domestic hot water
central heating systems.

1.1 Descri tion
1. The Baxi 100/2 HE Plus is a gas ired room sealed an
assisted condensing central heating boiler.
2. The maximum output o the boiler is preset at 75,000
Btu/hr. The boiler will automatically adjust down to
30,000 Btu/hr according to the system load. I required,
the output can be set to 100,000 Btu/hr. Please re er to
section 8.8.
3. It is designed or use on Natural Gas (G20).
4. The boiler is suitable or ully pumped open vented
central heating and domestic hot water systems and
sealed systems.
5. A label giving details o the model, serial number and
Gas Council number is situated on the rear o the lower
door panel (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 o the purpose
designed lues such as the standard horizontal lue kit, part
no 236921.
1.2 Im ortant Information
Man-made mineral fibre
• Some component parts o this appliance (insulation
pads, gaskets and rope seals) are manu actured rom man-
made mineral ibre.
• 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 rom the items i 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 a ter installation,
servicing or changing components.
• When disposing o any items manu actured rom man-
made mineral ibre care must be exercised.
• I any irritation o the eyes or severe irritation o the skin
is experienced seek medical attention.
1.0 Introduction
5
Fig. 1
Data Badge
Air Box Door
Lower Door Panel
Position o Label
Fig. 2

2.0 General Layout
6
2.1 Layout (Figs. 3,4,5 & 6)
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. PCB Housing Assembly
10. Gas Tap
11. Gas / Air Ratio Valve
12. Flow Pipe Connection
13. Return Pipe Connection
14. Flow Temperature Sa ety Thermostat - Black
15. Flow Temperature Thermistor - Red
16. Flow Switch (dry ire protection)
1
2
3
4
5
6
7
9
8
10
11
15 14
12
13
16
Fig. 4
Fig. 3
Fig. 5
2.2 O tional 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 or 2M etc.) 241695
Flue Bend x 2 - 45° (Reduce overall length o lue
by 0.5m when itting this bend) 241689
Flue Bend - 90° (Reduce overall length o lue
by 1m when itting each bend) 241687
Horizontal Extended Flue (1.75M) 5111457
VERTICAL FLUE (110/70)
Vertical Flue Terminal 242802
Vertical Flue Adaptor 5106888
Fig. 6

3.0 A liance O eration
7
3.1
1. Switched Live On: When the switched live switches
on i the low temperature is less than the set point
then pump overrun occurs. When the switched live
switches on i the low temperature is greater than the
set point then pump overrun occurs.
2. Pum On: The pump is on while the an, spark
generator and gas valve are o . A ter 10 seconds i the
low switch has made then an pre-purge occurs. A ter
10 seconds i the low switch has not made then anti-
cycle occurs.
3. Fan Pre-Purge: The pump and an are on while the
spark generator and gas valve are o . A ter 5 seconds
ignition occurs.
4. Ignition: The pump, an, spark generator and gas
valve are on. I a lame is detected then burner on
occurs. I a lame is not detected within 5 seconds and
less than 5 ignition attempts have been made then an
purge occurs. I a lame is not detected within 5 seconds
and 5 ignition attempts have been made then ignition
lockout occurs.
5. Burner On: The pump, an and gas valve are on while
the spark generator is o . Flow temperature is
controlled by varying the an speed (and thereby the
gas rate) to achieve optimum operation. I the low
temperature is greater than the set point or the TRVs
all shut down then an post purge occurs.
6. Fan Post Purge: The pump and an are on while the
spark generator and gas valve are o . A ter 5 seconds i
the TRVs are not shut down then pump overrun
occurs. A ter 5 seconds i the TRVs are shut down then
anti-cycle occurs.
7. Pum Overrun: The pump is on while the an, spark
generator and gas valve are o . A ter 1 minute anti-
cycle occurs.
8. Anti-cycle: The pump, an, spark generator and gas
valve are o . A ter 3 minutes i the low temperature is
less than the set point then pump on occurs. A ter 3
minutes i the low temperature is greater than the set
point then pump overrun occurs.
9. Ignition Lockout: The pump, an, spark generator and
gas valve are o . The boiler can only be reset by
manually using the reset button.
Mains On.
Flow
temperature less
than set point ?
YES
5 second
Fan Pre-Purge.
Flame Detected ?
Burner On.
Ignition
Lockout.
5 second
Ignition Period.
All TRVs
shut down ?
Ignition done and
5 attempts made ?
Ignition done
and less than 5
attempts made ?
Flow switch made ?
NO
YES
YES
YES
10 second
Pump On.
All TRVs
shut or Flow temperature
greater than set point ?
5 second
Fan Post Purge.
1 minute
Pump Overrun.
3 minute
Anti-cycle.
NO
YES
YES
YES
NO

A liance Category CAT I 2H
4.0 Technical Data
8
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
Packaged Boiler Carton 36.2
Packaged Flue Kit 3.6
Installation Li t Weight 26.0
Connections
Gas Supply - 1/2in BSPT
Central Heating Flow - 28mm
Central Heating Return - 28mm
Condensate Drain - 1 in BSP
Recommended System
Tem erature Dro
Condensing 20°C 36°F
Heat In ut (Gross) Max Min
(see note) kW 33.76 10.3
Btu/h 115,200 35,140
Heat Out ut
(Non Condensing 70° C Mean Water Temp)
Max Min
kW 30.18 9.2
Btu/h 102,980 31,390
Electrical Su ly 230V~ 50Hz
(Appliance must be connected to an
earthed supply)
Power Consum tion 80W
External Fuse Rating 3A
Internal Fuse Rating (BS 4265)
Fuse 3.15 AT (PCB)
Max Gas Rate (Natural Gas)
(A ter 10 Mins)
Btu/hr 102,980 75,000
m3/h 2.95 2.31
t3/h 104.2 81.6
Inlet Pressure at Gas Valve (Natural Gas)
Min 18.1 mbar
Max 22.5 mbar
(see Section 10.1)
Injector (Natural Gas)
6.5mm Diameter
Clearances
(For unventilated compartments see Section 7.5)
Both Sides 5mm Min
Above Casing 200mm Min
Below Casing 50mm Min
Front (For Servicing) 500mm Min
Front (In Operation) 5mm Min
0 10 20 30 40
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
A liance Ty e C13 C33 Nox Class 5
Heat Out ut
(Condensing 40° C Mean Water Temp)
Max Min
kW 32.61 10
Btu/h 113,280 34,120
Water Content
litres 2.6
pints 4.6
Static Head
max 30 metres (100 t)
min 1 metre (3.25 t)
Low Head 0.2m (8 in) min
System Detail
ully pumped open vented & sealed systems
Gas Connection
G1/2” B.S.P. Thread
Controls
boiler thermostat, sa ety thermostat,
low switch, electronic lame sensing,
temperature protection thermostat &
condensate blockage sensor
NOTE: The maximum out ut of the
boiler is factory set at 22.0kW (75,000
Btu/hr). This can be altered to
30.18kW (102,980 Btu/hr)
- see section 8.8.
The efficiency is 90.9%
This value is used in the UK Government’s Standard
Assessment Procedure (SAP) or energy rating o
dwellings. The test data rom which it has been
calculated has been certi ied by 0087.
SEDBUK Declaration For 100/2 HE Plus
Electrical Protection IPX2
CO/CO2 Ratio 0.001

5.0 Dimensions and Fixings
9
DIMENSIONS
A600mm
B320mm
C390mm
D125mm Ø Min.
E150mm
F125mm
SIDE FLUE (left and right)
For every 1m o horizontal lue
length, the clearance above the top
o the lue elbow should be 55mm to
incorporate the 3°
(1 in 20) all in the lue rom the
terminal to the elbow.
The 3° (1 in 20) all provided by the
elbow is to allow condensate to run
back to the boiler, or disposal
through the condensate discharge
pipe.
Flue length (Y)
up to 1m
1m - 2m
2m - 3m
Clearance (X)
55mm
110mm
165mm
360° Orientation
Tube Ø 110mm
DC
B
A
E
F
Y
3°
(1 in 20)
X
3°
(1 in 20)
Fig. 7
Fig. 8

6.0 System Details
10
6.1 Water Circulating Systems
1. The appliance is suitable or use with open vent ully
pumped systems and sealed systems .
The following conditions should be observed on all
systems:
• The static head must not exceed 30m (100 t) o water.
• The boiler must not be used with a direct cylinder.
• Drain cocks should be itted 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
o the boiler.
• Position isolating valves as close to circulating pump as
possible.
• It is recommended that the return pipe is itted with an
automatic air vent as close to the boiler as is practical.
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 e iciency o 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
o sludging, it is advisable to clean the system prior to
treatment in order to remove any sludge and reduce
the likelihood o these deposits damaging new
components.
• When itting new systems lux will be evident within
the system, which can lead to damage o system
components.
• All systems must be thoroughly drained and lushed
out. The recommended lushing and cleansing agents
are Betz-Dearborn Sentinel X300 or X400 and Fernox
Super loc Universal Cleanser which should be used
ollowing the lushing agent manu acturer’s instructions.
• System additives - corrosion inhibitors and lushing
agents/descalers should be suitable or aluminium and
comply to BS7593 requirements. The only system
additives recommended are Betz-Dearborn Sentinel
X100 and Fernox-Copal which should be used
ollowing the inhibitor manu acturer’s instructions.
Failure to flush and add inhibitor to the system will
invalidate the a liance warranty.
• It is important to check the inhibitor concentration
a ter installation, system modi ication and at every
service in accordance with the manu acturer’s
instructions. (Test kits are available rom inhibitor
stockists.)
• For in ormation or advice regarding any o the above
contact the Baxi Helpline.

6.0 System Details
11
6.3 Pi ework
1. The sizes o low and return pipes rom the boiler
should be determined by normal methods, according to
the requirements o the system. The connection to the
boiler is 28mm (compression).
2. Due to space requirements within the boiler
outercase, pipework should comprise o solder ittings.
3. A 20 °C (36°F) drop in temperature across the system
is recommended or condensing boilers. Existing radiators
may be oversized and so allow this, but where radiator
sizing is marginal it may be advisable to retain a system
temperature drop o 11°C (20°F).
4. In systems using non-metallic pipework it is necessary
to use copper pipe or the boiler Flow and Return. The
copper must extend at least 1 metre rom the boiler and
include any branches (Fig. 9).
6.4 Low Head Installation
1. Using a close couple arrangement the minimum head
is as shown in the diagrams (Figs. 10 & 11) subject to the
ollowing conditions:
a) The pump being adjusted to give an 20oC drop
across the boiler.
b) The pump must be itted on the low.
c) The pump must be itted in accordance with the
pump manu acturer's instructions.
d) The open vent pipe must be taken up rom a tee in a
horizontal section o the low pipe.
An alternative Low Head Installation (Fig. 12)
2. For heads below 400mm then a combined vent and
eed pipe may be connected. This must be a minimum o
22mm diameter. It is recommended that an air separator
is itted when using a combined eed and vent pipe.
6.5 Thermal Stores
1. When the 100/2 HE Plus is fitted in conjunction with
a thermal store, both jum ers must be removed from
the PCB, see Fig. 32 Section 8.8.
Ty ical Low Head Installation
If Conditions Require,
This System Possible
Alternative Low Head Installation
Boiler
500mm
45°
22mm
Open Vent
1000mm
Min
150mm
Max
15mm
Cold
Feed
400mm
Min Head
Return
Pump
Flow
Boiler
500mm
45°
22mm
Open Vent
400mm
Min Head
1000mm
Min
Automatic Air
Vent 15mm
Cold
Feed
150mm
Max
Return
Pump
Flow
Return
Pump
Flow
Boiler
200mm
Min
Air
Separator
22mm
Feed & Vent
Pipe
Fig. 10
Fig. 11
Fig. 12
Boiler Flow
Return
Copper
0.5m
Copper
1m
Copper
0.5m
Fig. 9

6.0 System Details
12
6.6 System Controls
This boiler does not require a by ass.
This boiler does not require a ermanent live.
The um only needs wiring directly to the boiler for
fully TRV’d systems.
1. To comply with Part L1 o the Building Regulations the
heating system into which the boiler is installed should
include the ollowing:
a) zone controls
b) timing controls
c) boiler control interlocks
2. Such a system needs to be ully pumped and must
provide independent temperature and time control to
both the heating and hot water circuits and have a boiler
interlock.
3. The boiler should be controlled so that it operates on
demand only. Where it is proposed to e ect control by
thermostatic radiator valves, a room thermostat (or
other device such as a low switch - a low switch is
integral to this boiler) should also be provided to switch
o the boiler when there is no demand or heating or hot
water.
4. The interlock or the CH circuit can be provided by
either a Room Thermostat or a ully TRV’d system with
the pump wired back to the boiler without a bypass.
Connection diagrams or both options or Y and S plan
systems are shown.
Y Plan
Diverter
Valve
Cylinder
Stat
Room
Stat
Boiler
Pump
Timer
230V
50Hz
L NE
L
N
CH on
HW on
HW o
LNE
L N P/FE
b
g/y w
o
gr
1
C2
g/y
S Plan
Valve
Cylinder
Stat
Room
Stat
Boiler
Pump
Timer
230V
50Hz
L NE
L
N
CH on
HW on
LNE
L N P/FE
Motor
S Plan
Valve
Motor
o
o
gr
b
g/y
b
gr
br
br
Y Plan
Diverter
Valve
Cylinder
Stat
Boiler
Pump
Timer
230V
50Hz
L NE
L
N
CH on
HW on
HW o
LNE
L N P/FE
b
g/y
o
gr
1
C2
w
g/y
S Plan
Valve
Cylinder
Stat
Boiler
Pump
Timer
230V
50Hz
L NE
L
N
CH on
HW on
LNE
L N P/FE
Motor
S Plan
Valve
Motor
o
o
gr
b
g/y
b
gr
br
br
Y Plan, Room Thermostat System, CH Interlocked By Room Thermostat
At least the Radiator(s) near the Room Thermostat not TRV’d
Pump run rom Switched Live
By-pass permitted but not required or Part L1 compliance
S Plan, Room Thermostat System, CH Interlocked By Room Thermostat
At least the Radiator(s) near the Room Thermostat not TRV’d
Pump run rom Switched Live
By-pass permitted but not required or Part L1 compliance
Y Plan, Fully TRV’d System, CH Interlocked By Boiler Flow Switch
Room Thermostat should not be itted
Pump must be run rom Boiler P/F connection or Part L1 compliance
By-pass not permitted (must be valved o ) or Part L1 compliance
S Plan, Fully TRV’d System, CH Interlocked By Boiler Flow Switch
Room Thermostat should not be itted
Pump must be run rom Boiler P/F connection or Part L1 compliance
By-pass not permitted (must be valved o ) or Part L1 compliance
Key to colours
b - Blue
br - Brown
w - White
o - Orange
gr - Grey
g/y - Green/Yellow

6.0 System Details
13
6.7 Sealed Systems (Fig. 13)
1. SAFETY VALVE - A sa ety valve complying with the
requirements o BS 6750 Part 1 must be itted close to
the boiler on the low pipe by means o a horizontal or
vertically upward connection with no intervening valve or
restrictions and should be positioned to acilitate testing.
The valve should be pre-set and non-adjustable to
operate at a pressure o 3 bar (45 Ib /in2). It must be
arranged to discharge any water or steam through a pipe
to a sa e outlet position.
2. PRESSURE GAUGE - A pressure gauge o minimum
range 0-4 bar (0-60 Ib /in2) with a ill pressure indicator
must be itted to the system, pre erably at the same point
as the expansion vessel in an easily visible position.
3. EXPANSION VESSEL - An expansion vessel
complying with the requirements o BS 4814 must be
itted to the system by means o a connection close to
the inlet side o the circulating pump in accordance with
the manu acturers instructions, the connecting pipe being
unrestricted and not less than 15mm (1/2in) nominal size.
The volume o the vessel should be suitable or the
system water content and the nitrogen or air charge
pressure should not be less than the system static head
(See Table. 1).
Further details o sealed system design can be obtained
rom BS 5449 and the British Gas publication entitled
'Speci ications or Domestic Wet Central Heating
Systems'.
4. FILLING POINT - A illing point connection on the
central heating return pipework must be provided to
acilitate initial illing and pressurising and also any
subsequent water loss replacement / re illing. The sealed
primary circuits may be illed or replenished by means o
a temporary connection between the primary circuit and
a supply pipe provided a ‘Listed’ double check valve or
some other no less e ective back low prevention device
is permanently connected at the inlet to the circuit and
the temporary connection is removed a ter use. The
illing method adopted must be in accordance with all
relevant water supply regulations and use approved
equipment.
Your attention is drawn to, or GB: Guidance G24.2 and
recommendation R24.2 o the Water Regulations Guide.
or IE: the current edition o I.S. 813 “Domestic Gas
Installations”.
5. MAKE UP SYSTEM - A method o replacing water lost
rom the system should be provided either by means o a
make up vessel o not more than 3 litres (5 pints)
capacity, mounted above the highest point o the system,
or by re-pressurisation o the system.
6. VENTING - A method o venting the system during
illing and commissioning must be provided by itting
automatic air vents or by venting manually.
7. HOT WATER STORAGE - The hot water storage
vessel must be o the indirect coil type. All components
used in the system must be suitable or operation at
110°C (230°F) and at the pressure allowed by the sa ety
valve.
Sa ety
Valve
Pressure
Gauge
Pump
Filling
Point
Air
Vent
3 Litre
Top Up Bottle
(i required)
Radiator
Circuit
Expansion
Vessel
System Drains at
Low Point
Max Boiler Flow
Tem = 82° C
Boiler
Fig. 13
Table. 1
Vessel Charge
Pressure (Bar)
0.5
1.0
1.5
Initial System
Pressure (Bar)
0.5
1.0
1.5
2.0
1.0
1.5
2.0
1.5
2.0
Multiply Total
Water Content O
System By (Litres)
0.067
0.112
0.207
0.441
0.087
0.152
0.330
0.125
0.265
Method o determining minimum valve o
expansion vessel volume or sealed systems
using Baxi Boilers
System Volume = 75 litres
Vessel Charge Pressure = 1.0 bar
Initial System Pressure = 1.5 bar
75 x 0.152 = 11.4 litres
Expansion Vessel Volume
Example :-
Then :-
NOTE
Where a vessel of the calculated size is not obtainable then
the next available larger size should be used.
Stop
Valve
Double
Check
Valve
DHW
Mains
Inlet
CH
Return
Temporary
Hose
Stop
Valve
Fig. 14

7.0 Site Requirements
14
7.1 Location
NOTE: Due to the high efficiency of the boiler a
lume of water va our will be discharged from the
flue. This should be taken into account when siting
the flue terminal.
1. The boiler may be itted to any suitable wall with the
lue passing through an outside wall or roo and
discharging to atmosphere in a position permitting
satis actory removal o combustion products and
providing an adequate air supply. The boiler should be
itted within the building unless otherwise protected by a
suitable enclosure i.e. garage or outhouse. (The boiler
may be itted inside a cupboard - see Section 7.2).
2. I the boiler is sited in an unheated enclosure then it is
recommended to incorporate an appropriate device or
rost protection in the system controls.
3. I the boiler is itted in a room containing a bath or
shower, it can only be itted in zone 3, (Figs. A & B shows
zone dimensions or a bathtub. For other examples re er
to Section 601 o the Current I.E.E. Wiring Regulations)
re erence must be made to the relevant requirements.
In GB this is the current I.E.E. Wiring Regulations and
Building Regulations.
In IE re erence should be made to the current edition o
I.S. 813 “Domestic Gas Installations” and the current
ETCI rules.
4. I the boiler is to be itted into a building o timber
rame construction then re erence must be made to the
current edition o Institute o Gas Engineers Publication
IGE/UP/7 (Gas Installations in Timber Framed Housing).
7.2 Ventilation of Com artments
1. Where the boiler is installed in a cupboard or
compartment, no air vents are required or cooling
purposes providing that the minimum dimensions below
are maintained.
Sides 15mm
Top 200mm
Bottom 50mm
Front 30mm
2. I the boiler is installed in a smaller cupboard or
compartment it must be ventilated according to
BS 5440 Part 2 and the minimum clearances given in
section 4.0 “Technical Data” maintained.
3. Any compartment should be large enough to house
the boiler only.
NOTE: The ventilation label on the front of the outer
case MUST NOT BE REMOVED when the a liance is
installed in a com artment or cu board.
Zone 2
Zone 1
Zone 0
Zone 2
Zone 3
Zone 3
Zone 2
Window
Recess
Window
Recess
0.6 m 2.4 m
Ceiling
Outside
Zones
Outside Zones
Zone 3
Zone 3
Zone 2
Zone 2
Zone 1
Zone 0
2.25 m
Zone 2
Window
Recess
3.0 m
2.4 m
0.6 m
Fig. A
Fig. B
In GB Only
In GB Only

7.0 Site Requirements
15
7.3 Clearances (Figs. 15 &16)
1. A lat vertical area is required or the installation o the
boiler.
2. These dimensions include the necessary clearances
around the boiler or case removal, spanner access and air
movement. Additional clearances may be required or the
passage o pipes around local obstructions such as joists
running parallel to the ront ace o the boiler.
3. For unventilated compartments see Section 7.2.
7.4 Gas Su ly
1. The gas installation should be in accordance with the
relevant standards. In GB this is BS 6891. In IE this is the
current edition o I.S. 813 “Domestic Gas Installations”.
2. The connection to the appliance is a 1/2in BSP Internal
Threaded Connection located at the rear o the gas
service cock (Fig. 6).
3. Ensure that the pipework rom the meter to the
appliance is o adequate size. (22mm pipework must be
connected to the appliance gas service cock. This should
extend or at least 3 meters back towards the gas meter).
Do not use i es of a smaller diameter than the boiler
gas connection.
7.5 Electrical Su ly
1. External wiring must be correctly earthed, polarised and
in accordance with relevant regulations/rules. In GB this is
the current I.E.E. Wiring Regulations. In IE re erence should
be made to the current edition o ETCI rules.
2. The mains supply is 230V ~ 50Hz used at 3A.
NOTE: “The method of connection to the electricity
su ly must facilitate com lete electrical isolation of the
a liance”.
Note! There is no method of isolating the boiler, at the
user interface.
Connection may be via a used double-pole isolator with a
contact separation o at least 3mm in all poles and servicing
the boiler and system controls only.
WARNING: The PCB Control and Fan
Assembly if 25 Vdc. Isolate at supply before
access.
50mm
600mm
390mm
200mm
5mm Min
5mm Min
5mm
500mm
For Servicing
Purposes
Fig. 15
Fig. 16 In Operation
3°
(1 in 20)
320mm

7.0 Site Requirements
16
7.6 Condensate Drain
FAILURE TO INSTALL THE CONDENSATE
DISCHARGE PIPEWORK CORRECTLY WILL AFFECT
THE RELIABLE OPERATION OF THE BOILER
The condensate discharge i e MUST NOT RISE at any
oint along its length. There MUST be a fall of AT LEAST
2.5° (50mm er metre) along the entire run.
NOTE: It is unnecessary to fit an air break in the discharge
i e.
1. The condensate outlet terminates in a 1” BSP nut and seal or
the connection o 21.5mm (3/4in) plastic over low pipe which
should generally discharge internally into the household
drainage system. I this is not possible, discharge into an outside
drain is acceptable.
2. Ensure the discharge o condensate complies with any
national or local regulations in orce.
BS 6798:2000 & Part H1 of the Building Regulations give
further guidance.
3. The discharge pipe should be run in a proprietary drain pipe
material e.g. PVC, PVC-U, ABS, PVC-C or PP.
4. Metal pipework is NOT suitable or use in condensate
discharge systems.
5. The pipe should be a minimum o 21.5mm diameter and
must be supported using suitably spaced clips to prevent
sagging.
6. Any pipe itted externally must be kept as short as possible to
minimise the potential o reezing.
7. Any condensate discharge pipework external to the building
(or in an unheated part o it e.g. garage) must be insulated to
protect against rost. It is also recommended that the pipe
diameter is increased to 32mm.
8. I the boiler is itted in an unheated location the entire
condensate discharge pipe should be treated as an external run.
9. In all cases discharge pipe must be installed to aid disposal o
the condensate. To reduce the risk o condensate being
trapped, as ew bends and ittings as possible should be used.
10. When discharging condensate into a soil stack or waste pipe
the e ects o existing plumbing must be considered. I soil pipes
or waste pipes are subjected to internal pressure luctuations
when WC's are lushed or sinks emptied then back-pressure
may orce water out o the boiler trap and cause appliance
lockout.
Examples are shown o the ollowing methods o termination:-
i) to an internal soil & vent pipe
ii) via an internal discharge branch (e.g. sink waste)
iii) to a drain or gully
iv) to a purpose made soakaway
Boiler
2.5° Minimum all
Termination to an internal soil and vent
i e
450mm min
Boiler
2.5° Minimum all
External termination via internal discharge
branch
e.g sink waste - downstream
Sink
Pipe must terminate
above water level but
below surrounding
sur ace
Boiler Pipe must terminate above
water level but below
surrounding sur ace
2.5° Minimum all
Termination to a drain or gully
Boiler
500mm min
2.5° Minimum all
Termination to a ur ose made soak-
away
Holes in the soak-away must
ace away rom the building
50mm per metre o pipe run
50mm per metre o pipe run
50mm per metre o pipe run
50mm per metre o pipe run

7.0 Site Requirements
17
7.7 Flue
NOTE: Due to the high efficiency of the boiler a
lume of water va our will be discharged from the
flue. This should be taken into account when siting
the flue terminal.
1. The ollowing guidelines indicate the general
requirements or siting balanced lue terminals.
For GB recommendations are given in BS 5440 Pt.1.
For IE recommendations are given in the current edition
o I.S. 813 “Domestic Gas Installations”.
2. I the terminal discharges onto a pathway or
passageway, check that combustion products will not
cause a nuisance and that the terminal will not obstruct
the passageway.
3. Take into consideration the e ect the plume o
vapour may have on neighbours when siting the lue.
4. Adjacent sur aces close to the lue terminal may need
protection rom the e ects o condensation.
Alternatively a lue de lector kit (part no. 248167) is
available.
5. For installation o the lue into an internal corner at
the 25mm dimension the lue de lector kit (part no.
248167) must be itted.
6. * Reduction to the boundary is possible down to
25mm but the lue de lector kit (part no. 248167) must
be itted.
7. I required a suitable terminal guard is available rom
Baxi or use with the lue de lector.
8. For itting under low so its and eaves it is acceptable
or the lue to project upto 500mm rom the ace o the
wall to the inside o the air intake. This can be painted i
required using a suitable external paint.
9. I a terminal is less than 2 metres (783/4in) above a
balcony, above ground or above a lat roo to which
people have access, then a suitable terminal guard must
be provided.
Fig. 17
Fig. 16a
300 min
Terminal
Assembly
TopView Rear Flue
Property Boundary Line
NOTE: The distance rom a anned draught appliance terminal
installed parallel to a boundary may not be less than 300mm in
accordance with the diagram below
Table. 2
Terminal Position with Minimum Distance (Fig. 17) (mm)
AaDirectly below an opening, air brick, opening
windows, etc. 300
BaAbove an opening, air brick, opening window etc. 300
CaHorizontally to an opening, air brick, opening window etc. 300
D Below gutters, soil pipes or drain pipes. 25
E Below eaves. 25
F Below balconies or car port roo . 25
G From a vertical drain pipe or soil pipe. 25
H From an internal (i) or external (ii) corner. (i) 25 (ii) 115
I Above ground, roo or balcony level. 300
J From a sur ace or boundary line acing a terminal. 600
K From a terminal acing a terminal (Horizontal lue). 1200
From a terminal acing a terminal (Vertical lue). 600
L From an opening in carport (e.g. door, window)
into the dwelling. 1200
M Vertically rom a terminal on the same wall. 1500
N Horizontally rom a terminal on the same wall. 300
R From adjacent wall to lue (vertical only). 300
S From an adjacent opening window (vertical only). 1000
aIn addition, the terminal should be no nearer than 150 mm to an
opening in the building abric ormed or the purpose o accommodating
a built-in element such as a window rame. See BS 5440 Pt. 1.
*

7.0 Site Requirements
18
7.8 Flue Dimensions
See Section 2.2. The standard horizontal lue kit allows
or lue lengths between 270mm (105/8”) and 800mm
(32”) rom elbow to terminal (Fig. 18).
The maximum ermissible equivalent flue length is: 4
metres (Fig. 18a).
NOTE: Each additional 45° of flue bend will
account for an equivalent flue length of 0.5m.
eg. 45° = 0.5m, 90° = 2 x 45° = 1m etc.
7.9 Terminal Guard (Fig. 19)
1. When codes o practice dictate the use o terminal
guards, they can be obtained rom most Plumbers’ and
Builders’ Merchants.
2. When ordering a terminal guard, quote the appliance
model number.
3. The lue terminal guard should be positioned
centrally over the terminal and ixed as illustrated.
7.10 Vertical Flue
1. Only a lue approved with the Baxi 100/2 HE Plus
can be used.
2. For in ormation on vertical lues consult the Baxi Flue
Guide Brochure or Notes or Guidance supplied with
the vertical lue pack.
Fig. 18
Fig. 18a
Pictorial exam les of flue runs where EQUIVALENT flue length equals 4m
Fig. 19
270mm 800mm
0.5m
1m
0.5m
0.5m

7.0 Site Requirement
19
Key Accessory Size Baxi Code
Number
Concentric Flue System 110mm diameter
A Horizontal lue kit 850mm 236921
B Straight extension kit 1000mm 241695
500mm 241694
250mm 241692
C Bend kit 93° 241687
D Bend kit (pair) 45° 241689
E Horizontal lue terminal 243013BAX
Clamp 110mm 243014BAX
Twin Flue System 80mm diameter
F Straight extension kit 1000mm 238690
500mm 238692
250mm 238694
G Bend kit 90° 246139
H Bend kit (pair) 45° 246138
Universal Vertical Flue Kits
J Twin lue adaptor kit 242757
K Vertical lue terminal 242802
L Universal roo tile 25°/50° 243015
M Roo cover plate kit 243131
N Flat roo lashing 243016BAX
R Vertical lue adapter 5106888
Clamp 80mm 238684
7.11 Flue o tions
Concentric
The maximum equivalent lengths are 4m (horizontal) or
(vertical). There lengths exclude the standard elbow and
lue/terminal assembly (horizontal) and terminal assembly
(vertical).
Twin Flue
The total maximum equivalent lue length is 150m.
NOTE: Each 1m o lue duct should be calculated as 2m.
Any additional “in line” bends in the lue system must be
taken into consideration. Their equivalent lengths are:
Concentric Pipes: 45° bend 0.5 m
93° bend 1.0 m
Twin Flue Pipe: 45° bend (air duct) 1.3 m
45° bend ( lue duct) 2.6 m
90° bend (air duct) 4.8 m
90° bend ( lue duct) 9.6 m
Detailed examples o equivalent lue length calculation are
given in the Installation Guidance Notes or each lue
system type.
(Documents 243501 and 243502 or concentric and twin
pipe respectively).
A - Standard Flue
D
E
B
C
K
L
D
M
J
F
J
N
HG
R

8.0 Installation
20
Check Site Requirements (section 7) before
commencing.
8.1 Initial Pre aration
The gas su ly, gas ty e and ressure must be
checked for suitability before connection (see Section
7.4).
NOTE: If the boiler wall late is to be re-hung,
follow both these instructions and those on the
boiler ack.
1. Remove the ixing template (Fig. 20) rom the carton.
2. A ter considering the site requirements (see Section
7.0) position the template on the wall ensuring it is level
both horizontally and vertically.
3. Mark the position o the centre hole or the wall
plate (Fig. 20).
4. Mark the centre o the lue hole (rear exit).
For side exit: project the horizontal side lue centre line
into the corner o the room and along the wall to
where the lue hole will be drilled. (Fig. 20).
The diagram (Fig. 21) shows the dimensions required
to ensure any horizontal lue is installed with the
correct all to the boiler. Mark the o set (V) dimension
and i required, mark the position o the gas and water
pipes. Remove the template.
5. Cut the hole or the lue (minimum diameter
125mm, see table (Fig. 20) or wall thicknesses and lue
diameters).
6. Drill and plug the wall as previously marked. Secure
the wall plate using the centre hole (Fig. 22).
7. Ensuring the wall plate is level both horizontally and
vertically, drill and plug at least 4 securing positions at
the top and bottom through the wall plate. Utilising the
slots available ensure the wall plate is square and secure
to the wall (Fig. 22).
8. Loosely route the condensate discharge pipe to the
lower le t hand side o the wall plate.
Wall Thickness
up to 227mm
up to 750mm
up to 1200mm
Flue Hole ø
125mm core drill
150mm core drill
175mm core drill
Fig. 20
Fig. 21
Fig. 22
Horizontal
Side Flue
Centre Line
EXAMPLE: Boiler is 2 metres away
from corner of wall, flue duct hole is
110mm u from horizontal side flue
centre line. This will maintain the
a rox 3° backfall to the boiler.
Wall Plate Template
Wall Plate
Edge o Boiler
Centralising
Screw
0.5
1.0
2.0
3.0
4.0
Distance in metres rom boiler to the wall.
For pipe lengths greater than 4m increase the o -set by 52mm
or every additional metre to maintain approx 3° inclination.
V
Flue Duct Hole
O set V (mm) 27 55 110 165 220
(metres)
(mm)
3°
Back all to the Boiler, ie. 2m lue o set (V) position 110mm
Exam le
2m
Exam le
V = 110mm
125mm
Centre
Hole