Baxi System
35/60 & 60/100
Gas Fired Wall Mounted System Boilers
Installation and
Servicing Instructions
Please leave these instructions with the user
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 System 35/60
G.C.No41 075 18
Baxi System 60/100
G.C.No41 075 19
Baxi is a BS-EN ISO 9001
Accredited Company
The boiler meets the requirements of Statutory Instrument
“ The Boiler (Efficiency) Regulations 1993 N
o
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 0051.
Product/Production certified by:
Notified Body 0051.
For GB/IE only.
3
1.0 Introduction 4
2.0 General Layout 5
3.0 Appliance Operation 6
4.0 Technical Data 7
5.0 Dimensions and Fixings 9
6.0 System Details 10
7.0 Site Requirements 12
8.0 Installation 17
9.0 Commissioning the Boiler 26
10.0 Completion 28
11.0 Servicing the Boiler 29
12.0 Changing Components 31
13.0 Illustrated Wiring Diagram 39
14.0 Fault Finding 40
15.0 Short Parts List 43
Section Page
Contents
Baxi UK Limited declare that no substances
harmful to health are contained in the
appliance or used during appliance
manufacture.
1.1 Description
1. The Baxi System 35/60 and 60/100 are fully
automatic gas fired wall mounted system boilers.
They are room sealed and fan assisted.
2. The boilers are set to give a maximum output of
17.5kW (35/60) or 29.3kW (60/100).
3. They are designed for use on Natural Gas
(G20) and can be converted to use Propane
(35/60 & 60/100) or Butane (35/60).
4. The boiler incorporates a circulating pump and
expansion vessel. It is suitable for use only on fully
pumped sealed systems.
5. The boiler data badge gives details of the
model, serial number and Gas Council number
and is situated on the control box. It is visible when
the case front panel is removed (Fig. 1).
6. The boiler is intended to be installed in
residential / commercial / light industrial E.M.C.
environments on a governed meter supply only.
7. The boiler must be installed with one of the
purpose designed flues such as the standard
horizontal flue kit, part no. 247719.
8. All systems must be thoroughly flushed and
treated with inhibitor (see section 6.1).
1.2 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
“I
NSTALLATION OF GAS APPLIANCES”. The installation must be
carried out by a CORGI Registered Installer or other
competent person and be in accordance with the relevant
requirements of G
AS SAFETY (Installation and Use)
R
EGULATIONS, the BUILDING REGULATIONS (Scotland)
(Consolidation), the L
OCAL BUILDING REGULATIONS, the
C
URRENT I.E.E. WIRING REGULATIONS and the bye laws of the
Local Water Undertaking. Where no specific instructions are
given, reference should be made to the relevant BRITISH
STANDARD CODES OF PRACTICE.
1.3 Optional Extras
Various flue extensions, bends, vertical flue
kits,control accessories etc. are availble as
optional extras. These are detailed in a separate
publication.
1.0 Introduction
4
Data Badge
Fig. 1
Control Box
“Benchmark” Log Book
As part of the industry-wide “Benchmark” initiative all Baxi boilers now
include an Installation, Commissioning and Service Record Log Book.
Please read the Log Book carefully and complete all sections relevant to
the appliance and installation. These include sections on the type of
controls employed, flushing the system, burner operating pressure etc.
The details of the Log Book will be required in the event of any warranty
work. Also, there is a section to be completed at each subsequent regular
service visit. The Log Book must be left with the user.
Case Front Panel
NOTE: 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.
2.0 General Layout
5
2.1 Layout
1. Air Pressure Switch
2. Expansion Vessel
3. Burner Manifold
4. Automatic Air Vent
5. Circulation Pump
6. Drain Off Point
7. Pressure Relief Valve
8. DHW Relay PCB
9. System Pressure Gauge
10. PCB
11. Control Box
12. Spark Generator
13. Flame Sensing Electrode
14. Spark Electrode
15. Burner
16. Primary Heat Exchanger
17. Fan Assembly
18. On/Off/Reset Selector Switch
19. Central Heating Temperature Control
20. Flame Failure
21. Safety Thermostat
22. Fault on Fan or Flue
23. Fault on Pump or Low System Pressure
24. Temperature Indication Only
25. Fault on Central Heating Sensor
26. Power On
27. Hot Water Mode
28. Central Heating Mode
29. Burner On
When neons 20 to 25 are constantly illuminated,
they indicate the temperature of the central heating
water.
17
16
15
12
13
14
11
10
9
18
19
9
6
5
3
4
7
2
1
30° 40° 50° 60° 70° 80°
2
1
0
4
3
bar
30° 40° 50° 60° 70° 80°
20 21
22
23
25
26
28 29
24
27
8
3.0 Appliance Operation
6
3.1 Operating Mode (Fig. 2)
1. With a demand for heating, the pump circulates
water through the primary circuit. At a predetermined flow rate the hydraulic differential
pressure switch operates, initiating the ignition
sequence.
2. The main burner ignites at low rate, then the
gas valve controls the gas rate to maintain the
heating temperature measured by the
temperature sensor.
3. When the flow temperature exceeds the setting
temperature, a 3 minute delay occurs before the
burner relights automatically (anti-cycling). The
pump continues to run during this period.
4. When the demand is satisfied the burner is
extinguished and the pump continues to run for a
period of 3 minutes (Pump Overrun).
IMPORTANT: When the selector switch is in
the ‘0’ (Off) position the electrical supply to the
boiler is isolated. The boiler will not operate.
3.3 Frost Protection Mode
1. The frost protection mode is integral to the
appliance and functions only with the selector
switch (see Section 2.1) in the domestic hot water
and central heating position. If the system
temperature falls below 5° C then the boiler will
fire on its minimum setting until a flow temperature
of 30° C is reached. Further protection can be
incorporated by using a system frost thermostat.
3.4 Pump Protection
1. With the selector switch (see Section 2.1) in
either the central heating or central heating and
hot water position the pump will automatically
operate for 1 minute in every 24 hours to prevent
sticking.
1
2
4
5
6
7
8
19
18
9
10 12 11
14
13
15
16
17
3
Key
1 Heat Exchanger
2 Burner
3 Ignition Electrode
4 Flame Sensing Electrode
5 Gas Valve
6 Pump
7 Automatic Air Vent
8 Pressure Relief Valve
9 Boiler Drain Point
10 Gas Inlet
11 Boiler Flow
12 Boiler Return
13 Pressure Gauge
14 Automatic By-Pass
15 Hydraulic Differential Pressure Sensor
16 Safety Thermostat
17 Central Heating Temperature Sensor
18 Expansion Vessel
19 Water Heating Sensor
Boiler Primary Circuit
Fig. 2
4.0 Technical Data
7
Flue Terminal Diameter 100mm
Dimensions Projection 95mm
Outercase Dimensions
Casing Height - 780mm
Overall Height Inc Flue
Elbow - 980mm
Casing Width - 450mm
Casing Depth - 345mm
Clearances
Both Sides 5 mm Min
Above Casing 200 mm Min
Below Casing 200 mm Min
Front 450 mm Min (For Servicing)
Front 5 mm Min (In Operation)
Weights kg
Packaged Boiler Carton 45
Packaged Flue Kit 3
Installation Lift Weight 37
Central Heating Primary Circuit
Pressures
bar
Safety Discharge 3
Max Operating 2.5
Min Operating 0.2
Recommend Operating 1-2
Pump - Grundfos UP 15-50
Available Head See graph below
Expansion Vessel - (Integral with appliance)
bar
Min Pre-charge Pressure 0.5
litre
Max Capacity of
CH System 125
Primary Water Content
of Boiler (unpressurised) 1.0
Connections copper tails
Gas Supply - 22mm
Central Heating Flow - 22mm
Central Heating Return - 22mm
Pressure Relief Discharge - 15mm
Temperatures
C.H. Flow Temp (adjustable)
35°C to 85°C max (± 5°C)
Heat Input (Gross)
Max Min
kW 19.4 10.6
Btu/h 66,200 36,170
Heat Output Max Min
kW 17.5 9.3
Btu/h 59,720 31,740
Electrical Supply 230V~ 50H
z
(Appliance must be connected to an
earthed supply)
Power Consumption 170W
External Fuse Rating 3A Maximum
Internal Fuse Rating
Fuse 2A Fast Blow to BS 4265
Appliance Category CAT II
2H 3+
Max Gas Rate (Natural Gas - G20)
(After 10 Mins)
m3/h 2.05
ft3/h 72.4
Inlet Pressure (Natural Gas - G20)
mbar 20
in wg 8
Burner Injector (Natural Gas - G20)
12 x 1.28mm Diameter
Burner Pressure (Natural Gas - G20)
Max Rate Min Rate
mbar 6.9 ± 0.5 2.5 ± 0.5
in wg 2.8 ± 0.2 1.0 ± 0.2
Appliance Type C
12
C
32
NOxClass 3
This value is used in the UK Government’s Standard
Assessment Procedure (SAP) for energy rating of dwellings.
The test data from which it has been calculated have been
certified by 0051.
SEDBUK Declaration For System Boiler 35/60
The seasonal efficiency (SEDBUK) is 78.8 %
Electrical Protection
IPX5D
4.1 System 35/60
LPG Gases Propane - G31 and
Butane - G30
Burner Injector 12 x 0.65mm diameter
Burner Pressure
Propane mbar
in wg
Butane mbar
in wg
Inlet Pressures
mbar
in wg
Max Rate
36.2 ± 0.5
14.5 ± 0.2
28.8 ± 0.5
11.5 ± 0.2
Min Rate
10.8 ± 0.5
4.3 ± 0.2
7.7 ± 0.5
3.1 ± 0.2
Propane
37
14.8
Butane
28/30
11.2
5
4.5
4
3.5
3
2.5
2
Metre wg
1.5
1
0.5
0
l/h
Pump - Available Head
200 400 600 800 1000 1200
0
4.0 Technical Data
8
4.2 System 60/100
Flue Terminal Diameter 100mm
Dimensions Projection 95mm
Outercase Dimensions
Casing Height - 780mm
Overall Height Inc Flue
Elbow - 980mm
Casing Width - 450mm
Casing Depth - 345mm
Clearances
Both Sides 5 mm Min
Above Casing 200 mm Min
Below Casing 200 mm Min
Front 450 mm Min (For Servicing)
Front 5 mm Min (In Operation)
Weights kg
Packaged Boiler Carton 47
Packaged Flue Kit 3
Installation Lift Weight 39
Central Heating Primary Circuit
Pressures
bar
Safety Discharge 3
Max Operating 2.5
Min Operating 0.2
Recommend Operating 1-2
Pump - Grundfos UP 15-60
Available Head See graph below
Expansion Vessel - (For Central Heating
only. Integral with appliance)
bar
Min Pre-charge Pressure 0.5
litre
Max Capacity of
CH System 125
Primary Water Content
of Boiler (unpressurised) 1.1
Connections copper tails
Gas Supply - 22mm
Central Heating Flow - 22mm
Central Heating Return - 22mm
Pressure Relief Discharge - 15mm
Temperatures
C.H. Flow Temp (adjustable)
35°C to 85°C max (± 5°C)
Heat Input (Gross)
Max Min
kW 32.6 11.9
Btu/h 111,250 40,610
Heat Output Max Min
kW 29.4 10.4
Btu/h 100,330 35,490
Electrical Supply 230V~ 50H
z
(Appliance must be connected to an
earthed supply)
Power Consumption 190W
External Fuse Rating 3A Maximum
Internal Fuse Rating
Fuse 2A Fast Blow to BS 4265
Appliance Category CAT II
2H 3P
Max Gas Rate (Natural Gas - G20)
(After 10 Mins)
m3/h 3.45
ft3/h 122
Inlet Pressure (Natural Gas - G20)
mbar 20
in wg 8
Burner Injector (Natural Gas - G20)
15 x 1.28mm Diameter
Burner Pressure (Natural Gas - G20)
Max Rate Min Rate
mbar 12.5 ± 0.5 1.8 ± 0.5
in wg 5.0 ± 0.2 0.7 ± 0.2
Appliance Type C
12
C
32
NOxClass 3
Electrical Protection
IPX5D
This value is used in the UK Government’s Standard
Assessment Procedure (SAP) for energy rating of dwellings.
The test data from which it has been calculated have been
certified by 0051.
SEDBUK Declaration For System Boiler 60/100
The seasonal efficiency (SEDBUK) is 78.2 %
LPG Gases Propane - G31
Burner Injector 15 x 0.77mm diameter
Burner Pressure
Propane mbar
in wg
Inlet Pressures
mbar
in wg
Max Rate
34.4 ± 0.5
13.8 ± 0.2
Min Rate
5.1 ± 0.5
2.0 ± 0.2
37
14.8
6
5.5
5
4.5
4
3.5
3
2.5
2
Metre wg
1.5
1
0.5
0
l/h
Pump - Available Head
200 400 600 800 1000 1200
0
5.0 Dimensions and Fixings
9
Dimensions
A 780mm
B 345mm
C 450mm
D 107mm Ø Min.
E 200mm
F 190mm
G 143mm
360° Orientation
Tube Ø 100mm
D
C
B
A
E
G
F
Heating
Return
(22mm)
Heating
Flow
(22mm)
Pressure Relief
Valve
(15mm)
Gas
Inlet
(22mm)
130 mm
130 mm
65 mm
Tap Rail
6.0 System Details
10
6.1 Central Heating Circuit
1. The appliance is suitable for fully pumped SEALED
SYSTEMS ONLY.
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 efficiency of the system
will deteriorate as corrosion sludge accumulates
within the system, risking damage to pump and
valves, boiler noise and circulation problems.
• For optimum performance after installation this
boiler and its associated central heating system must
be flushed in accordance with the guidelines given in
BS 7593 “Treatment of water in domestic hot water
central heating systems”.
• This must involve the use of a proprietary cleanser,
such as BetzDearborn Sentinel X300 or X400, or
Fernox Superfloc. Full instructions are supplied with
the products, but for immediate information please
contact BetzDearborn (0151 420 9563) or Fernox
(01799 550 811) directly.
• For long term protection against corrosion and
scale, after flushing it is recommended that an
inhibitor such as BetzDearborn Sentinel X100, or
Fernox MB-1 or Copal is dosed in accordance with
the guidelines given in BS 7593.
Failure to flush and add inhibitor to the system
may invalidate the appliance warranty.
• It is important to check the inhibitor concentration
after installation, system modification and at every
service in accordance with the manufacturer’s
instructions. (Test kits are available from inhibitor
stockists.)
• For information or advice regarding any of the
above contact the Baxi Helpline.
6.2 Bypass
1. The boiler is fitted with an automatic integral
bypass.
6.3 System Control
1. The boiler is designed for use in a heating
system that incorporates external controls, i.e. a
minimum of a timer device.
2. For optimum operating conditions and maximum
economy the fitting of a programmable room
thermostat, such the Baxi Combi Controller, is
recommended.
6.0 System Details
11
6.4 System Filling and Pressurising
1. A filling point connection on the central heating
return pipework must be provided to facilitate
initial filling and pressurising and also any
subsequent water loss replacement/refilling.
2. The filling method adopted must be in
accordance with the Water Supply (Water
Fittings) regulations and the Water Bylaws
(Scotland).
3. Your attention is drawn to: Paragraph 24 of
Schedule 2 Section 8 of the publication Water
Regulations Guide which gives recommendations
and guidance on approved methods for filling
sealed systems.
4. The sealed primary circuits may be filled or
replenished by means of a temporary connection
between the primary circuit and a supply pipe
provided the arrangement in accordance with
Diagram R24.2a of the Water Regulations Guide.
5. The temporary hose must be completely
removed at both ends after use.
6.5 Expansion Vessel
1. The appliance expansion vessel is pre-charged
to 0.5 bar. The vessel is suitable for correct
operation for system capacities up to 125 litres.
For greater system capacities an additional
expansion vessel must be fitted - refer to BS 7074
Pt 1.
6.6 Pressure Relief Valve (Fig. 4)
1. The pressure relief valve is set at 3 bar,
therefore all pipework, fittings, etc. should be
suitable for pressures in excess of 3 bar.
2. The pressure relief discharge pipe should be
not less than 15mm dia, run continuously
downward, and discharge outside the building,
preferably over a drain. It should be routed in
such a manner that no hazard occurs to
occupants or causes damage to wiring or
electrical components. The end of the pipe should
terminate facing down and towards the wall.
3. The discharge must not be above a window,
entrance or other public access. Consideration
must be given to the possibility that boiling
water/steam could discharge from the pipe.
Fig. 3
Fig. 4
Stop
Valve
Double
Check
Valve
Mains
Cold
Water
CH
Return
Temporary
Hose
Pressure Relief Valve
Discharge Pipe
Stop
Valve
7.0 Site Requirements
12
7.1 Information
1. 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 the current G
AS SAFETY (Installation
and Use) R
EGULATIONS, the BUILDING REGULATIONS
(Scotland)(Consolidation), the LOCAL BUILDING
REGULATIONS, the current I.E.E. WIRING REGULATIONS
and the bye laws of the LOCAL WATER UNDERTAKING.
Where no specific instruction is given reference
should be made to the relevant BRITISH
STANDARD CODES OF PRACTICE. For Ireland
install in accordance with IS 813 “I
NSTALLATION OF
GAS APPLIANCES”.
7.2 B.S. Codes of Practice
Standard Scope
BS 6891 Gas Installation.
BS 5546 Installation of hot water supplies for
domestic purposes.
BS 5449 Part 1 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.
WARNING - 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 G
AS SAFETY (Installation
and Use) R
EGULATIONS.
7.3 Clearances (Figs. 5 & 6)
1. A flat vertical area is required for the installation
of the boiler.
2. These dimensions include the necessary
clearances around the boiler for case removal,
spanner access and air movement. Additional
clearances may be required for the passage of
pipes around local obstructions such as joists
running parallel to the front face of the boiler.
7.4 Location
1. The boiler may be fitted to any suitable wall with the
flue passing through an outside wall or roof and
discharging to atmosphere in a position permitting
satisfactory removal of combustion products and
providing an adequate air supply. The boiler should be
fitted within the building unless otherwise protected by
a suitable enclosure i.e. garage or outhouse. (The
boiler may be fitted inside a cupboard-see Section 7.5).
2. If the boiler is sited in an unheated enclosure then it
is recommended to leave the On/Off/Reset Selector
Switch in the domestic hot water and central heating
position to give frost protection.
3. If the boiler is fitted in a room containing a bath or
shower reference must be made to the current I.E.E.
WIRING REGULATIONS and BUILDING REGULATIONS. If the
boiler is to be fitted into a building of timber frame
construction then reference must be made to the
current edition of Institute of Gas Engineers Publication
IGE/UP/7 (Gas Installations in Timber Framed
Housing).
200mm Min
780mm
450mm
200mm Min
5mm Min
5mm Min
5mm Min
450mm Min
For Servicing
Purposes
Fig. 5
Fig. 6
In Operation
7.0 Site Requirements
13
7.5 Ventilation of Compartments
1. Where the appliance is installed in a cupboard
or compartment, no air vents are required.
2. BS 5440: Part 2 refers to room sealed
appliances installed in compartments. The
appliance will run sufficiently cool without
ventilation.
7.6 Gas Supply
1. The gas installation should be in accordance
with BS 6891.
2. The connection to the appliance is a 22mm
copper tail located at the rear of the gas service
cock (Fig. 7).
3. Ensure that the pipework from the meter to the
appliance is of adequate size. Do not use pipes of
a smaller diameter than the boiler gas connection
(22mm).
7.7 Electrical Supply
1. External wiring must be correctly earthed,
polarised and in accordance with current I.E.E.
Wiring Regulations.
2. The mains supply must be 230V ~ 50Hzand
fused at 3A maximum.
NOTE: The method of connection to the
electricity supply must facilitate complete
electrical isolation of the appliance.
Connection may be via a fused double-pole
isolator with a contact separation of at least
3mm in all poles and servicing the boiler and
system controls only.
3. When the system includes an indirect domestic
hot water cylinder it is recommended that a
cylinder thermostat is used in conjunction with a
3 port 2 position valve or 2 port zone valve.
4. A switched live feed should be taken from the
cylinder thermostat to the boiler. This will operate
the boiler when there is a demand for domestic
hot water (see Section 8.8 for details of
suggested system wiring schemes).
Fig. 7
Gas Service Cock
7.0 Site Requirements
14
7.8 Flue
1. The flue terminal position must be in
accordance with the current editions of B.S.
5440 Part 1, and either Part J of the Building
Regulations England and Wales or Part F of
the Building Standards (Scotland)
Regulations as appropriate.
2. If 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. If a terminal is less than 2 metres above a
balcony, above ground or above a flat roof to
which people have access, then a suitable
terminal guard must be provided.
Terminal Position with Minimum Distance (Fig. 9) (mm)
A Directly below an openable window, air vent or any other
ventilation opening. 300
B Below gutter, drain/soil pipe. 25
C Below eaves. 25
D Below a balcony/car port roof. 25
E From vertical drain pipes and soil pipes. 25
F From internal or external corners. 25
G Above adjacent ground or balcony level. 300
H From a surface facing a terminal. 600
I Facing a terminals. 1200
J From opening (door/window) in carport into dwelling. 1200
K Vertically from a terminal on the same wall. 1500
L Horizontally from a terminal on the same wall. 300
M Above an opening, air brick, opening window etc. 300
N Horizontally to an opening, air brick, opening window etc. 300
L
G
G
E
J
D
K
G
A
A
D
F
H,I
B,C
F
Likely flue positions requiring
a flue terminal guard
M
N
Fig. 9
300 min
Terminal
Assembly
Top View Rear Flue
Property Boundary Line
Loading...