baxi Solo 3 PFL System 30, Solo 3 PFL System 40, Solo 3 PFL System 50, Solo 3 PFL System 60, Solo 3 PFL System 70 User guide

Baxi Solo 3 PFL System

Wall Mounted Powered Flue System Boiler

Gas Fired Central Heating Unit

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 built 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 Solo 3 PFL System 30

G.C.No. 41 075 25

Baxi Solo 3 PFL System 40

G.C.No. 41 075 26

Baxi Solo 3 PFL System 50

G.C.No. 41 075 27

Baxi Solo 3 PFL System 60

G.C.No. 41 075 28

Baxi Solo 3 PFL System 70

G.C.No. 41 075 29

Baxi Solo 3 PFL System 80

G.C.No. 41 075 31

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 0086.

Product/Production certified by:
Notified Body 0086.

For use in GB/IE only

3

1.0 Introduction 4

2.0 General Layout 5

3.0 Technical Data 6

4.0 System Details 8

5.0 Site Requirement 11

6.0 Installation 14

7.0 Commissioning the Appliance 32

8.0 Fitting the Outercase 34

9.0 Overheat Cut-Off Device 35

10.0 Annual Servicing 36

11.0 Changing Components 38

12.0 Short Parts List 44

13.0 Fault Finding 45

Section Page

Contents

Model Heat Output

30

8.79kW (30,000 Btu/h)

40 11.72kW (40,000 Btu/h)
50 14.65kW (50,000 Btu/h)
60 17.58kW (60,000 Btu/h)
70 20.5kW (70,000 Btu/h)

80 23.44kW (80,000 Btu/h)

1.0 Introduction

4 1

1.1 Description

1. The Baxi Solo 3 PFL System is a gas fired room
sealed fan assisted central heating system boiler
with outputs as shown in the table below.

2. Each appliance is preset at a heat input rating
and is designed for use on NATURAL GAS only.

3. All boilers are suitable for sealed fully pumped
systems only.

4. The appliance incorporates a circulating pump
and expansion vessel.

5. The appliance data badge is fitted to the
combustion box door, an abbreviated version is on
the inside of the front panel.

6. All illustrations show the Solo 3 PFL System 50
boiler.

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 the current G

AS SAFETY

(Installation and Use) REGULATIONS, 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 instructions are
given, reference should be made to the relevant

BRITISH STANDARD CODES OF PRACTICE.

2. All systems must be thoroughly flushed and
treated with inhibitor (see Section 4.2).

1.3 Important Information

Man-Made Mineral Fibre

a) Some component parts of this appliance
(insulation pads, gaskets and rope seals) are
manufactured from man-made mineral fibre.

b) Prolonged or excessive exposure to this
material may result in some irritation to the eyes,
skin or respiratory tract.

c) It is advisable to wear gloves when handling
these items.

d) Irritant dust will only be released from the items
if they are broken up or subjected to severe
abrasion. In these instances a suitable dust mask
and goggles should be worn.

e) Always thoroughly wash hands after installation,
servicing or changing components.

f) When disposing of any items manufactured from
man-made mineral fibre care must be exercised.

g) If any irritation of the eyes or severe irritation of
the skin is experienced seek medical attention.

Users Operating Label

Data Badge

Combustion Box Door

Fig. 1

Fig. 2

“Benchmark” Log Book

As part of the industry-wide “Benchmark” intiative 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.

IMPORTANT:

STATEMENT OF ADJUSTMENT. Check that the state of adjustment
given on the data plate is compatible with local supply conditions

British Gas Service
Test Point.

For use by B.G.
Personnel only

2.0 General Layout

5

2.1 Layout (Figs. 3 & 4)

1. Wall Plate

2. Automatic Air Vent

3. Expansion Vessel

4. Pressure Relief Valve

5. Circulation Pump

6. Water Pressure Gauge

7. Position of Optional Timer

8. Gas Tap

9. Control Knob

10. Electronics Housing

11. Gas Valve

12. Burner

13. Heat Exchanger

14. Fan Assembly

15. Pressure Switch

16. Overheat Thermostat

17. Thermostat Sensor

1

2

Fig. 4

Fig. 3

3

4

5

6

7

8

9

10

11

12

13

14

15

16

17

STANDARD

B.S. 6891

B.S. 5546

B.S. 5449

B.S. 6798

B.S. 5440: Pt 1

B.S. 5440: Pt 2

B.S. 7074: Pt 1

SCOPE

Gas Installation.

Installation of hot water supplies for

domestic purposes.

Forced circulation hot water systems.

Installation of gas fired hot water

boilers.

Flues.

Ventilation.

Sealed Systems

B.S. Codes of Practice, most recent

version should be used

3.0 Technical Data

6

Model 30 40 50 60 70 80

Heat Output kW 8.79 11.72 14.65 17.58 20.5 23.44

Btu/h 30,000 40,000 50,000 60,000 70,000 80,00

Heat Input kW 10.99 14.65 18.32 21.98 25.64 29.31

Btu/h 37,500 50,000 62,500 75,000 87,500 100,000

Burner Pressure mbar 16.0 ±0.5 16.0 ±0.5 16.0 ±0.5 16.0 ±0.5 16.0 ±0.5 16.0 ±0.5

in wg 6.4 ±0.2 6.4 ±0.2 6.4 ±0.2 6.4 ±0.2 6.4 ±0.2 6.4 ±0.2

Gas Rate CV 38mj/m31.04m3/h 1.39m3/h 1.74m3/h 2.08m3/h 2.43m3/h 2.78m3/h

(after 10 mins) 36.86ft3/h 49.0ft3/h 61.3ft3/h 73.5ft3/h 86.75ft3/h 99.24ft3/h

Lifting Weight kg 40 40 40 49.1 49.1 49.1

lbs 88 88 88 108 108 108

Water Content litres 2.1 2.1 2.1 2.6 2.6 2.6

pints 3.2 3.2 3.2 4.5 4.5 4.5

Outercase Height 850mm 850mm 850mm 850mm 850mm 850mm

Dimensions Width 490mm 490mm 490mm 490mm 490mm 490mm

Depth 320mm 320mm 320mm 320mm 320mm 320mm

Flue Terminal Diameter 100mm

Dimensions Depth 70mm

Connections Flow 22mm Cu tail

Return 22mm Cu elbow

Heat Exchanger Cast iron monobloc

System Design fully pumped sealed systems only

Gas Connection 22mm Cu tail

Electrical Supply 230V ~ 50Hz fused 5A - 90W

Controls boiler thermostat, intermittent pilot & electronic flame sensing

timed pump over-run, frost protection thermostat

Internal Fuse 4AF 250V to BS4256 situated on control board

3.0 Technical Data

7

(4) 10

(8) 20

(16) 40

(24) 60

(12) 30

(20) 50

(28) 70

(32) 80

(36) 90

(40) 100

(44) 110

(48) 120

2 4 6 8 1012 1416 18 2022

Water Flow Rate litres / min

Pressure Drop mbar (in wg)

2426 28 30

(52) 130

(4) 10

(8) 20

(16) 40

(24) 60

(12) 30

(20) 50

(28) 70

(32) 80

(36) 90

(40) 100

(44) 110

(48) 120

2 4 6 8 1012 1416 18 2022

Water Flow Rate litres / min

Pressure Drop mbar (in wg)

2426 28 30

(52) 130

30, 40 and 50 models

60, 70 and 80 models

Hydraulic Resistance Charts

• This appliance is only intended for installation on a governed supply.

• PMS = 3 bar pressure class 2

• Max CH water pressure 3 bar

• Type C

12C32C52

• Nox class 1

• Appliance category

I2H2H - G20 - 20mbar

• Ref: 86/AU/588

• Burner Injector Sizes: 30=B31 40=B32 50=B33 60=B34 70=B35 80=B36

• This boiler is designed to operate at a maximum water temperature of 85° C.

68mm

Model Seasonal Efficiency

(SEDBUK) (%)

30 79.4

40 78.4

50 78.0

60 78.5

70 78.2

80 78.7

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 0086.

SEDBUK Declaration For Solo 3 PFL System

All Models

Top of Outercase

120mm

4.0 System Details

8

4.1 Water Circulating Systems

Water Circulating Systems

1. The appliance is suitable for fully pumped
sealed systems only.

The following conditions should be observed
on all systems:

• The boiler must not be used with a direct
cylinder.

• Drain cocks should be fitted 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 of the boiler.

• Air vents should be fitted to all system high
points.

• All components used in the system must be
suitable for operation at 110°C (230°F).

4.2 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 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 7593:1992 “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 7593:1992.

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.

4.3 Bypass Requirements

1. The boiler is fitted with a pump overrun device
which allows the removal of residual heat from the
boiler.

NOTE: The pump overrun will operate for
approximately 8 minutes. The system design must
therefore always provide an open circuit for water
to circulate between the boiler flow and return.

Typical Systems
Arrangement

Option A

Boiler

Air Vent

Radiator
Circuit

Fully Pumped System

Air
Vent

Radiator
Circuit

Twin Zone

Valve System

Air
Vent

Radiator
Circuit

3 Port Divertor

Valve System

Option B

Radiator

Circuit

Option C

Fig. 4a

Fig. 4b

Fig. 4c

Fig. 4d

Examples of systems which require a
bypass are:-

a) A system controlled by non-electrical
valves e.g. mechanical thermostatic control
valves both on the radiators and the hot
water circuit.

b) A system using twin zone valves (e.g.
Honeywell 'S' Plan) (Fig. 4c).

c) A system using a 3 port divertor valve
(Fig. 4d) does not normally require a
bypass therefore this system is
recommended. The exception to this is
where thermostatic radiator valves are used
and then a bypass is required.

NOTE: For ‘S’ Plan systems the bypass
flow circuit must be situated between
pump and zone valves as option A
shows (Fig. 4b).

The bypass circuit can be:-

a) For all boilers a minimum of 6 metres of
22mm copper pipe, (measured between the
boiler flow and return connections). It
should be fitted with a lock shield valve
opened at least 1 full turn or a proprietary
bypass valve set to give a minimum flow
rate of 8 litres/min (1.8 gal/min) (Option C,
Fig. 4a & Option A, Fig. 4b).

b) A radiator fitted with lock shield valves.
The radiator output should be a minimum of
800 watts (2,700 Btu/h). Typically a
convector type radiator with an area of
3750 cm2(4 sq ft) is adequate (Option B,
Fig. 4a).

c) Any circuit that provides the same
operating conditions as option A or option B
(Figs. 4a & 4b).

4.0 System Details

9

4.4 Pipework

1. The sizes of flow and return pipes from the
boiler should be determined by normal methods,
according to the requirements of the system.

2. The connections to the boiler are 22mm copper
tails.

4.5 System Components

1. All components used in the system must be
suitable for operation at 110° C (230° F) and at
the pressure allowed by the safety valve.

4.6 System Controls

1. For optimum operating conditions, the heating
system into which the boiler is installed should
include a control system.

2. Such a system will comprise of a timer control
and separate room or cylinder thermostats as
appropriate. (An integral twin channel programmer
is available as an optional extra).

3. The boiler should be controlled so that it
operates on demand only.

4. Operation of the system under control of the
boiler thermostat & TRV’s only does not produce
the best results.

4.7 Thermal Stores & Heat Stores

1. If a thermal store or heat store is being used, it
should be one approved for use with the Baxi Solo
3 PFL System Boiler.

4.0 System Details

10

4.8 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 all relevant water supply bye-laws
and use approved equipment.

3. Your attention is drawn to: IRN 302 and Byelaw

14.

4. The sealed primary circuits may be filled or
replenished by means of a temporary connection
(Filling Loop) between the circuit and a supply
pipe, provided a WRC approved double check
valve or some other no less effective backflow
prevention device is permanently connected at the
inlet to the circuit and the temporary connection
(Filling Loop) is removed after use (Fig. 5).

4.9 Expansion Vessel

1. The appliance expansion vessel is pre-charged
to 1 bar (10 lb/in

2

). Therefore, the minimum cold fill
pressure is 1 bar. The vessel is suitable for correct
operation for system capacities up to 125 litres
(27.5gal). For greater system capacities an
additional expansion vessel must be fitted - refer to
BS 7074 Pt 1.

4.10 Pressure Relief Valve (Figs. 6 & 7)

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 under fault
conditions boiling water/steam could discharge
from the pipe.

4. The pressure relief valve must not be used for
draining the system/boiler.

Discharge Pipe

Fig. 5

Stop Valve

Double
Check
Valve

Mains

CH
Return

Filling Loop

Fig. 7

Fig. 6

Pressure Relief Valve

5.0 Site Requirements

11

5.1 Location

1. The appliance may be fitted to any suitable wall
with the flue passing through an outside wall and
discharging to atmosphere in a position permitting
satisfactory removal of combustion products and
providing an adequate air supply. The appliance
should be fitted within the building unless otherwise
protected by a suitable enclosure ie. garage or
outhouse. (The appliance may be fitted inside a
cupboard. Cooling ventilation and insulation of the
cupboard are not required, see section 5.5.)

2. If the appliance 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 appliance is to be fitted into a building of timber
frame construction then reference must be made to
the Institute of Gas Engineers document UP7 (“Guide
for Gas Installation in Timber Framed Dwellings”).

3. Recommendations for flues are given in BS 5440
Part 1.

5.2 Minimum Clearances (Fig. 8)

1. A flat vertical area is required for the installation of
the boiler.

2. These dimensions include the necessary
clearances around the appliance 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 appliance.

3. If fitted inside a cupboard the clearance of 500mm
shown is only necessary when the cupboard door is
open. A clearance of 5mm (3/16in) is required when
the door is closed.

5.3 Flue Position

1. For installations where the flue terminal is
inaccessible from the outside, an internal fitting kit is
available. This can be obtained free of charge from
your local merchant.

2. The following guide lines indicate the general
requirements for siting balanced flue terminals.

3. If the terminal is fitted within 1 metre (39in) of a
plastic gutter, within 500mm (191/2in) of a painted
eave or a painted gutter, an aluminium shield of at
least 1 metre (39in) long should be fitted to the
underside of the gutter or painted surface. An air
space of 5mm (3/16in) should be left between shield
and gutter (Fig. 9).

4. 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.

5. If the outer surface of an outside wall is of
combustible material, it should be protected by fitting
the flue trim provided.

Fig. 8

Fig. 9

500mm for servicing

5mm during operation

5mm5mm

850mm

50mm

100mm

Aluminium

Shield

490mm

320mm

5.0 Site Requirements

12

5.3 Flue Position (Cont)

WARNING - The addition of anything that may

interfere with the normal operation of the
appliance (e.g. FLUE DAMPERS,
ECONOMISERS,etc.) without the express
written permission of Baxi UK Limited could
invalidate the appliance warranty and infringe
the GAS SAFETY (Installation and Use)
REGULATIONS.
If a terminal is less than 2 metres (78

3

/4in)
above a balcony, above ground or above a flat
roof to which people have access then a
suitable terminal guard must be provided.

6. The flue terminal position must always be

in accordance with the current edition 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.

7. Table 2 and Fig. 10 show the positioning of the
flue terminal relative to buildings and other
structures.

8. The dimensions of the flue terminal are shown
in Section 3.0 Technical Data.

5.4 Flue Dimensions

1. Flue extensions are available as optional
extras for installations up to 3 metres
horizontal.

2. Vertical flue kits are available up to 4
metres in length. Vertical twin flue kits are
available up to 15 metres in length.

3. The standard telescopic flue is suitable for use
with rear flue lengths between 100mm (4in) and
500mm (19

5

/8in).

4. Where it is intended to pass the flue through a
combustible wall or timber framed dwelling,
reference should be made to the Institute of Gas
Engineers document UP7 - Guide for Gas
Installations in Timber Framed Dwellings.

5. If the flue is more than 1 metre (39

3

/8in) long, it

is required that it is supported.

6. All above dimensions are taken from the

respective faces of the outer case.

Fig. 11

Maximum lengths for side flue using the standard telescopic flue kit

355mm

335mm

Table. 2

Fig. 10

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

Horizontal Terminal Position with Minimum Distance (mm)

A Directly below an openable window, air vent or any other

ventilation opening. 300
B Below gutter, drain/soil pipe. 150
C Below eaves. 200
D Below a balcony/car port roof. 200
E From vertical drain pipes and soil pipes. 150
F From internal or external corners. 300
G Above adjacent ground or balcony level. 300
H From a surface or boundary facing a terminal. 600
I Facing a terminal. 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

NOTE: Scotland Only - The distance from a fanned draught appliance
terminal installed at right angles to a boundary may not be less than
300mm in accordance with the diagram below.

300 min

Terminal
Assembly

Top View Rear Flue

Property Boundary Line

5.0 Site Requirements

13

5.5 Ventilation of Compartments

1. Where the appliance is installed in a cupboard
or compartment, no air vents are required.

NOTE: The ventilation label on the front of the
outer case MUST NOT BE REMOVED when
the appliance is installed in a compartment or
cupboard.

2. B.S. 5440 Part 2 Clause 4.2 refers to room
sealed appliances installed in compartments.
This appliance will run sufficiently cool without
ventilation.

5.6 Gas Supply

1. The gas installation should be in accordance
with BS 6891.

2. The connection of the appliance is a 22mm
copper tail on the tap rail (Fig. 12).

3. The pipework should be sized to account for
the distance of the appliance from the meter, the
pipe routing and maximum input of the appliance.

5.7 Electrical Supply

External wiring must be correctly earthed,
polarized and in accordance with CURRENT
I.E.E. WIRING REGULATIONS.

The mains supply is 230V ~ 50Hz fused at 5A.

NOTE: The method of connection to the
electricity supply must facilitate complete
electrical isolation of the appliance.

Connection may be made via a fused double­pole isolator with a contact separation of a least
3mm in all poles and serving the appliance and
system controls only.

Fig. 12

Gas Connection

Flow Connection

Return Connection

Pressure Relief
Connection

6.0 Installation

14

6.1 Initial Preparation

1. Open the hinged lower door panel and
carefully disengage the door stay. Remove the
door by opening it 90° and pulling forward
(Fig. 13).

2. Remove the 2 screws holding the outer case
to the combustion box (Fig. 13).

3. Place the outer case in a safe place until
required.

4. Remove the R clip from the latch securing the
combustion box to the back plate and release
the latches (Fig. 14a & 14b).

5. Lift and remove the combustion box and
backplate from the wall plate (Fig. 14). Place the
combustion box and backplate on its back.

IMPORTANT - When installing a Solo 3
System with a rear flue see section 6.2 Fan
Outlet Restrictor before continuing the
installation.

6. Proceed to the relevant section for flueing the
appliance either to the Rear, Left, Right or
Vertically.

NOTE: For Vertical flueing or flue lengths
greater than standard, the relevant optional
extra kits must be obtained and their
instructions followed.

Fig. 13

Lower Door Panel

Outer Case
Fixing Screw

Retaining Latch

Wall Plate

Back Plate Slots

Hooks

‘R’ Clip

Fig. 14

Fig. 14a

Fig. 14b

Door Stay

6.0 Installation

15

6.2 Initial Preparation (continued)

1. Remove the fixing template (Fig. 14c) from the
carton.

2. After considering the site requirements
(see Section 5.2) position the template on the
wall ensuring it is level both horizontally and
vertically. If it is desired that the appliance is
positioned centrally between two points, mark
the wall accordingly and align the template
centreline with this mark.

3. Mark at least four suitable fixing holes for the
wall plate. Preferably the two at either side of the
flue airbox should be used. Fixing points X and Y
can be used for additional securing of the
combustion box assembly to the wall. Points X
must be used when the optional security kit is
used.

4. Drill the anchorage holes 63mm (2

1

/2in) deep

to accept suitable wall plugs.

5. Mark the centre of the flue hole (rear exit). For
side exit, mark as shown. If required, mark the
position of the gas, water and pressure relief
discharge pipes. Remove the template.

6. Cut the hole for the flue (minimum diameter
107mm).

7. For rear flue applications continue as
described in Section 6.4. Side flue installations
are covered in Section 6.7.

Fig. 14c

Vertical Flue
Centre Line

Horizontal Flue
Centre Line

Solo 3 System Boiler

GAS SUPPLY FLOW RETURN PRESSURE

RELIEF

100 mm

Minimum

Clearance

50 mm

Minimum Clearance

5 mm
Minimum Clearance
From Outercase To

Edge Of Template

Fixing Points marked X and Y can be

used for additional securing of the

combustion box to the wall.

Points X must be used when optional

security bolts are fitted

TEMPLATE

Boiler

Center Line

Profile of

Outercase

5 mm
Minimum Clearance
From Outercase To

Edge Of Template

Side And Top

Flue Template

X

X

X

X

Y

Y

Fixing Template

6.0 Installation

16

6.3 Fan Outlet Restrictor

Rear Flue only up to 500mm (195/8in)

1. Release the four latches holding the
combustion box door (Fig 16). Remove the
combustion box door by pulling forward (Fig. 16).

2. Release the 5-pin electrical plug connecting
the pressure switch and fan (Fig. 15). Withdraw
the fan assembly by pulling forwards from the
top edge (Fig. 16).

3. Take the restrictor (supplied in the kit of
parts), check that the number stamped on the
restrictor matches the appliance (e.g. 50
stamped on the restrictor is for 50 PF appliance)

4. Fit the restrictor to the fan outlet flange,
bending the 3 lugs equally ensuring the restrictor
seals against the fan outlet flange (Fig. 17).

5. Re-assemble the fan assembly and
combustion box door ensuring that the flexible
tubes from the fan unit to the pressure switch are
routed correctly and that they are not kinked or
flattened (Fig. 16).

Fan Assembly

5 Pin Electrical Plug

Combustion Box Door

Fan Outlet Restrictor

Fan Outlet Flange

Fig. 17

Fig. 16

Fig. 15

Flexible Tubes

6.0 Installation

17

6.4 Rear Flue Preparation

Wall thickness 285mm - 500mm (115/16- 193/8) go
to section 5.6.

Wall Thickness 100mm - 284mm (4in - 11

3

/16in)

If the wall thickness is less than 285mm (11

3

/16in),
it will be necessary to cut the components of the
flue to the appropriate size.

1. Measure the wall thickness (Fig. 19). Mark this
dimension on the Flue Duct from the flared end
and cut the waste off the plain end (Fig. 20).

2. Take the Flue Terminal Assembly and
measure from the terminal end the wall thickness
and subtract 40mm (Fig. 21). Cut the waste off
the plain end.

Wall Thickness - 40mm (all boilers)

3. The cardboard support should be installed onto
the flue tubes to ensure the assembly is
supported during cutting (Fig. 23 & 24).

4. Measure the same amount from the flange end
of the Air Duct and cut the waste off the plain end
(Fig. 22).

Wall Thickness - 40mm (all boilers)

6. Go to section 6.5.

Wall Thickness

Fig. 20

Fig. 21

Fig. 22

Fig. 23

Fig. 24

Fig. 19

Waste Wall Thickness

Flue Duct

WasteWall Thickness - 40mm

Wall Thickness - 40mmWaste

Cardboard

Support

Flue Terminal Assembly

Air Duct

Cardboard

Support

6.0 Installation

18

6.5 Assembly of Rear Flue

1. Remove the rear air box blanking plate from
the wall plate by releasing the three screws
(Fig. 25).

2. Remove the blanking cap at the rear of the
turret, by pushing and turning anti-clockwise to
release the bayonet fitting (Fig. 25).

3. Locate the swaged end of the flue duct over
the bayonet fitting on the turret, taking care not to
damage the 'O' ring. Lock the flue duct in place by
pressing in and turning clockwise (Fig. 26).

4. Engage the bayonet slots of the air duct over
the location lugs on the back plate opening and
press and turn clockwise to secure the air duct to
the back plate (Fig. 27).

5. In order to increase security of the flue, the
bayonet tags may be deformed to secure the flue
in position.

6. Take the flue terminal assembly and engage
on the flue and air ducts. Slide the flues together
to the desired wall thickness.

7. Tape the outer duct sections together with the
tape provided ensuring a good seal is made
(Fig. 27a).

Tape

Fig. 27a

Fig. 25

Fig. 26

Fig. 27

6.0 Installation

19

6.6 Fitting the Wall Plate

1. Engage the assembly into the hole previously
cut in the wall and slide in place (Fig. 28).

2. Secure the assembly to the wall at the
previously drilled anchorage points with suitable
screws. Before finally tightening the screws,
check that the assembly is level.

3. Make good between the wall and the air duct
outside the building if the internal fitting kit has
not been used (Fig. 29).

4. The flue trim provided may be fitted if required,
to neaten the wall around the terminal (Fig. 30).

5. To fit the flue terminal trim:

a) The trim should be fitted once the flue is
secure.

b) Take the three edge clips from the kit and fit
them equi-spaced onto the inner flange of the
trim (Fig. 29a).

c) With the flanges towards the wall pass the trim
over the terminal. If required a bead of sealant
may be applied to the rear face of the trim.

d) Push firmly on the trim to ensure the edge clips
engage on the flue.

Fig. 30

Fig. 28

Fig. 29

Fig. 29a

Edge Clip

Flue Trim

Flue Trim

6.0 Installation

20

6.7 Left or Right Flue

NOTE: If the flue terminal is inaccessible from

outside the building, it is necessary to fix the
internal fitting kit in position before continuing
with the installation. (See section 5.15 Internal
Fitting Kit of these instructions).

1. The procedure for fitting the appliance flued to
the left or right hand side is the same.

2. Left Hand Side maximum flue 355mm.

3. Right Hand Side maximum flue 335mm.

4. Optional flue extensions are available.

5. Using the previously marked flue hole centre,
mark the horizontal centre line for the flue
assembly (Fig. 31).

6. Extend this line either left or right as required,
to the corner of the room (Fig. 31).

7. Extend the horizontal centre line around the
corner for approximately 300mm (12 in). Ensure
that the line remains horizontal by checking with a
spirit level (Fig. 32).

8. From the wall template cut out the ‘D’ shaped
section. Line up the horizontal triangular cut outs
with the extended 300mm (12 in) line and make
sure that the flat of the template is butted up
against the corner of the wall (Fig. 33).

9. If the appliance mounting wall is out of true, use
string or a straight edge to determine the true
corner position and mark a vertical line to
accommodate the flat edge of the template.

10. Holding the template firmly, mark the vertical
centre line for the flue assembly by marking the
point at the outer corners of the upper and lower
cut outs (Fig. 34).

11. Remove the template and draw a vertical line
between the two marks. The intersection of the
vertical and horizontal lines is the centre of the
flue hole (Fig. 35).

12. For installations where the flue terminal is
inaccessible from the outside, an internal fitting kit
is available. This can be obtained free of charge
from your local merchant.

13. If using the internal fitting kit a 117mm (4

5

/8in)

diameter hole is required.

14. Cut a hole approximately 107mm (4

1

/4in)
diameter in the masonry for the 100mm (4 in)
diameter flue duct (Fig. 36). (Use of a core drill is
recommended. When using a core drill, it is
important to keep the drill level and square,
particularly with the wall onto which the boiler is to
be fitted).

Fig. 31

Fig. 32

Fig. 33

Fig. 34

Fig. 35

Fig. 36

Maximum lengths for side flue using the standard telescopic flue kit

355mm

335mm

6.0 Installation

21

145mm (Left Hand Flue)
165mm (Right Hand Flue)

6.8 Side Flue Preparation

1. For both Left and Right Hand Flue - Measure
the distance from the wall to the nearest line
marked from the template. This will be known as
dimension X (Fig. 37).

2. Measure the thickness of the wall from the
inside. This will be known as Wall Thickness
(Fig 38).

3. To make up the total flue length, add 145mm

(L/H Flue) or 165mm (R/H Flue) to the

Wall Thickness + X dimension:

Total flue length =

Wall Thickness + X +

145mm (L/H Flue)

Wall Thickness + X + 165mm (R/H Flue).

NOTE: if total calculated flue length exceeds

500mm (19

5

/8in), a flue extension kit will be

required.

CUTTING THE FLUE

NOTE: If Wall Thickness + X is less than;

140mm (L/H Flue) or
120mm (R/H Flue),

it will be necessary to cut the components of
the flue to make up the appropriate size.

4. Take the Flue Duct and measure the
dimension below from the flared end. Cut the
waste off the plain end (Fig. 40).

Wall Thickness + X + 145mm (L/H Flue)
Wall Thickness + X + 165mm (R/H Flue)

5. Take the Flue Terminal Assembly and
measure from the terminal end the dimension
below (Fig. 41). Cut the waste off the plain end.

Wall Thickness + X + 110mm (L/H Flue)
Wall Thickness + X + 130mm (R/H Flue)

6. Measure the same amount from the flange end
of the Air Duct and cut the waste off the plain end
(Fig. 42).

Wall Thickness +X + 110mm (L/H Flue)
Wall Thickness + X + 130mm (R/H Flue)

7. The cardboard support supplied in the flue
pack should be installed onto the flue tubes of the
flue terminal assembly to ensure the flue is
supported during cutting (Fig. 43 & 44).

Wall Thickness + X + 145mm (L/H Flue)

Wall Thickness + X + 165mm (R/H Flue)

Wall

Thickness

X

Wall Thickness + X + 110mm (L/H Flue)

Wall Thickness + X + 130mm (R/H Flue)

Wall Thickness + X + 110mm (L/H Flue)

Wall Thickness + X + 130mm (R/H Flue)

Fig. 37

Fig. 38

Fig. 39

Fig. 40

Fig. 41

Fig. 42

Waste

Flue Duct

Flue Terminal Assembly

Air Duct

Wall Thickness

X

Total Flue Length

Waste

Waste

Cardboard

Support

Fig. 44

Fig. 43

Cardboard

Support

6.0 Installation

22

6.9 Fitting the Flue and Wall Plate

1. NOTE: There are two options for fitting the
flue and wall plate they are:

Method A - Fitting the flue and wall plate as an
assembly (usually used where there are no side
clearance problems).

Method B - Pre-fitting the flue through the wall,
fitting the wall plate to its position on the wall and
then connecting the two together (usually used
where side clearances are restrictive).

6.10 Method A

1. Remove the left or right hand air box blanking
plate, as appropriate, from the back plate air box
by releasing the three screws (Fig 46).

2. Rotate the turret to face the selected opening
(Fig. 45) and remove the side blanking cap by
pushing in and turning anti-clockwise to release
the bayonet fitting (Fig. 46).

3. Locate the swaged end of the flue duct over
the bayonet fitting on the turret, taking care not
to damage the 'O' ring. Lock the flue in place by
pressing in and turning clockwise (Fig. 47).

4. Ensure that the 'O' ring seal is in position
against the sealing flange.

5. Fit the air duct over the flue duct and draw
towards the air box on the back plate. Engage
the bayonet slots of the air duct over the location
lugs of the back plate opening and press and
turn clockwise to secure the air duct to the air
box (Fig. 48).

6. In order to increase security of the flue, the
bayonet tags may be deformed to secure the
flue in position.

7. Take the flue terminal assembly and engage
on the flue and air ducts. Slide the flues together
to the desired flue length. Tape the outer duct
sections together with the tape provided
ensuring a good seal is made (Fig. 49).

Tape

Turret

Fig. 49

Fig. 45

Fig. 46

Fig. 47

Fig. 48

6.0 Installation

23

6.10 Method A (Cont)

7. Engage the assembly into the hole previously
cut in the wall and slide into place (Fig. 50).

8. Secure the assembly to the wall at the
previously drilled anchorage points with suitable
screws. Before finally tightening the screws,
check that the assembly is level.

9. Make good between the wall and the air duct
inside and outside the building if the internal fitting
kit has not been used (Fig. 51).

10. The flue trim provided may be fitted if
required, to neaten up the make-up around the
terminal (Fig. 52).

11. To fit the flue terminal trim:

a) The trim should be fitted once the flue is
secure.

b) Take the three edge clips from the kit and fit
them equi-spaced onto the inner flange of the trim
(Fig. 51a).

c) With the flanges towards the wall pass the trim
over the terminal. If required a bead of sealant
may be applied to the rear face of the trim.

d) Push firmly on the trim to ensure the edge clips
engage on the flue.

Fig. 52

Fig. 51

Fig. 50

Fig. 51a

Edge Clip

Flue Trim

Flue Trim

6.0 Installation

24

6.11 Method B

1. Remove the left or right hand air box blanking
plate, as appropriate, from the back plate air box
by releasing the three screws (Fig. 54).

2. Rotate the turret to face the selected opening
(Fig. 53) and remove the side blanking cap by
pushing in and turning anti-clockwise to release
the bayonet fitting (Fig. 54).

3.Locate the swaged end of the flue duct over the
bayonet fitting on the turret, taking care not to
damage the ‘O’ ring. Lock the flue duct in place by
pressing in and turning clockwise (Fig. 55).

4. Engage the bayonet slots of the air duct over
the location lugs on the back plate opening and
press and turn clockwise to secure the air duct to
the back plate (Fig. 56).

5. Engage the flue and air ducts into the hole
previously cut in the wall and through holes in
other partitions (cupboards, walls etc.).

6. Secure the back plate to the wall at the
previously drilled anchorage points with suitable
screws. Before finally tightening the screws,
check that the assembly is level.

7. Take the flue terminal assembly and pass
through the cut hole from outside. Engage on the
flue and air ducts. Slide the flues together to the
desired wall thickness. Tape the outer duct
sections together with the tape provided ensuring
a good seal is made (Fig. 57).

8. In order to increase security of the flue, the
bayonet tags may be deformed to secure the flue
in position.

9. Make good between the wall and the air duct
inside and outside the building if the internal fitting
kit has not been used (Fig. 58).

10. The flue trim provided may be fitted if
required, to neaten up the make-up around the
terminal (Fig. 59).

11. To fit the flue terminal trim:

a) The trim should be fitted once the flue is
secure.

b) Take the three edge clips from the kit and fit
them equi-spaced onto the inner flange of the trim
(Fig. 58a).

c) With the flanges towards the wall pass the trim
over the terminal. If required a bead of sealant
may be applied to the rear face of the trim.

d) Push firmly on the trim to ensure the edge clips
engage on the flue.

Fig. 59

Fig. 54

Fig. 55

Fig. 56

Fig. 53

Fig. 57

Fig. 58

Tape

Turret

Fig. 58a

Edge Clip

Flue Trim

Flue Trim

6.0 Installation

25

6.12 Terminal Guard

1. When codes of practice dictate the use of
terminal guards, they can be obtained from most
plumbers and builders merchants nationwide.

2. When ordering a terminal guard, quote the
appliance model number.

3. There must be a clearance of at least 50mm
between any part of the terminal and the guard.

6.13 Fitting a Terminal Guard (Fig. 60)

1. Position the guard over the terminal on the
outside wall. Ensure the guard is equally spaced
about the terminal. Mark the fixing positions.

2. Drill and plug fixing the positions then secure
the guard to wall.

Fig. 60

6.0 Installation

26

6.14 Internal Fitting Kit

1. The internal fitting kit (available from
merchants quoting Baxi Part N

o

. 236441) is
suitable for walls between 100mm (4in) and
285mm (11

3

/16in) in thickness.

2. TO INSTALL THE KIT - Mark the flue hole
centre as described in section 6.3 or 6.8. Cut a
hole in the masonry approximately 117mm (4

5

/

8

in) diameter for the internal fitting kit. The use of
a core drill is recommended. (When using a core
drill, it is important to keep the drill level and
square).

3. Measure the wall thickness and from this
dimension subtract 10mm (

3

/8in) (Fig. 61).

4. Remove the wall liner from its packing and
remove the end piece (Fig. 62).

5. Mark off the dimension, wall thickness - 10mm
(

3

/8in), measuring from the beaded end of the
duct and cut off the remaining length of the duct.
Ensure that the cut is square and reasonably
straight (Fig. 63).

Wall Thickness - 10

Wall Thickness

Fig. 61

Fig. 62

Fig. 63

6.0 Installation

27

6.14 Internal Fitting Kit (Cont)

6. Refit the end piece to the liner and open out to
the thickness of the wall. Seal the two pieces
together using the tape provided with the kit
(Fig 64).

7. Slide the assembled wall liner into the hole in
the wall until the tags stop against the inner wall
with the seam of the liner uppermost. Mark the
positions of the holes in the tags on the wall and
then rotate liner so that tags reveal marks
(Fig. 65).

8. Drill and plug the wall in these positions
(Fig. 66).

9. Rotate liner back until the tags align with the
holes drilled and secure it to the wall using
suitable screws (Fig. 67).

10. Make good between the edge of the liner
and the outside wall with cement mortar or a
similar substance, by reaching through the liner
and pressing the mortar between liner and the
outside brick work (Fig. 68). Make good between
the liner and the inside wall. Apply soap solution
to the ‘O’ ring inside the liner.

11. The rest of the installation may now proceed
as described.

Fig. 64

Fig. 65

Fig. 66

Fig. 67

Fig. 68

6.0 Installation

28

6.15 Connection and Flushing

1. Connect the gas, water and pressure relief
discharge pipes to the valves on the wall plate
using the copper tails supplied. Ensure that the
sealing washers are fitted correctly to the water
connections.

2. Connect the filling loop and fill and thoroughly
flush the system (see system details,
section 4.2 & 4.7).

6.0 Installation

29

6.16 Fitting the Combustion

Box Assembly

CAUTION: Care must be taken when lifting

the boiler on to the backplate. Get assistance
if required.

1. Remove the sealing tape from the taps.

2. Offer the combustion box assembly up to the
wall plate and locate the slots on the back plate
on to the hooks on the wall plate (Fig 70 & 71).

3. While fitting the combustion box care must be
taken not to damage the boiler pipework and
fittings.

4. Engage the two retaining latches and secure
the right hand one with the ‘R’ clip previously
removed (Fig 69 & 72).

5. Take the three washers from the kit and insert
them between the water flow and return pipes,
pressure relief discharge pipe and their
corresponding taps. The pressure relief washer
is the smaller of the three.

6. Tighten all the nuts to the taps.

7. Undo the four screws securing the transit
bracket to the combustion box door and chassis.
Remove the bracket and discard.

Fig. 73

Fig. 70

Fig. 71

Fig. 72

Fig. 69

‘R’ Clip

Transit Bracket

Retaining Latch

Wall Plate

Back Plate Slots

Hooks

6.0 Installation

30

NOTE: The method of connection to the
electricity supply must facilitate complete
electrical isolation of the appliance.
Connection may be made via a fused double
pole isolator with a contact separation of at
least 3mm (

1

/8in) in all poles and serving the
appliance and system controls only. All cables
should be routed to avoid hot surfaces.

WARNING - T

HIS APPLIANCE MUST BE EARTHED.

4 core input cable for connection to the appliance
must be not less than 0.75mm

2

(24 x 0.2mm)
PVC grade to IEC 227 code 53 (heat resisting).
External controls and the appliance MUST be
supplied via the same isolator.

NOTE: Polarity of the appliance MUST be
correct otherwise the appliance will not
operate correctly.

or

b

r

g/y

w

br

g

w

bk

gy

br

b

Pump

N

Main Gas Valve

Pilot Gas Valve

Fan

Pressure Switch

Thermostat Sensor

Overheat
Thermostat

Control
Potentiometer
& Switch

Spark Electrode

N

N

N

External
Controls

S/L

L

230V

L

b

r

b

or

b

br

br

gy

w

y

bk

y

or

or

or/bk

or/bk

r/b

y/bk

y/r

w

PCB

Schematic

Wiring

Diagram

Pressure
Switch

Control Potentiometer
& Switch

Thermostat

Sensor

Spark Electrode

Fan

Gas Valve

Key

br - brown b - blue
r - red w - white
bk - black or - orange
gy - grey y - yellow
g - green
g/y - green & yellow
or/bk - orange & black
r/b - red & blue
y/bk - yellow & black
y/r - yellow & red

6.17 Electrical Connections

r/b

y/r

y/bk

or/bk

or/bk

y

or

or

y

Overheat
Thermostat

b

gy

bk

w

Pump

br

g/y

b

6.0 Installation

31

6.18 Making the Electrical Connections

1. Remove the cover from the control box by
removing the 2 screws (Fig. 74).

2. Slide the box forward for easier access.

3. Route the supply cable via the control box from
the rear of the appliance.

4. The terminal strips may be removed by
carefully pulling forward. Connect the supply
cable to the terminal strip (Fig. 77).

IMPORTANT - When installing in conjunction
with a thermal store or heat store please refer
to the store manufacturers installation
instructions when wiring the boiler.

5. The pump is connected to the boiler P.C.B.
terminals.

6. A permanent live must be connected to the 'L'
terminal.

7. The switched live must be connected to the
'S/L' terminal.

8. Clamp the cable in the grip provided. Ensure
that the length of the supply cable is such that the
current carrying wires become taut before the
earth wires if the cable should pull out of the cable
clamp (Fig. 76).

9. Tuck the cable along the side of the box and
clip to the wall where necessary. Make sure
sufficient slack is left to allow the box to slide
forward for future access. A cable clip is fitted at
the side of the box.

10. For optional integral clock kit follow
instructions provided.

Switched Live

Permanent Live

Neutral

Earth

Pump Earth

Pump Neutral

Pump Live

Fig. 76

Fig. 74

Fig. 75

Fig. 77

7.0 Commissioning the Appliance

32

7.1 Commissioning the Appliance

1. Pressurise the system to 1.0 bar then close
and disconnect the filling loop. Check for water
leaks.

2. Purge away air from the supply pipe at the gas
service cock. (BS 6891: 1988) (Fig. 78).

3. Ensure that the electrical supply is isolated.

4. Check the electrical supply for earth continuity,
polarity, short circuit and resistance to earth.

5. Turn the gas service cock to the ON position
and check for gas soundness up to the gas valve.

6. Loosen the pressure test point screw on the
gas control valve (there is no need to completely
remove this screw to check the burner pressure)
and connect a pressure gauge (Fig. 81).

7. Turn the boiler thermostat control knob fully
anti-clockwise to the OFF position marked 0
(Fig. 79).

8. Ensure that the electricity supply is turned ON
and set any external controls to the ON position.

9. Turn the boiler thermostat knob fully clockwise.

10. The fan will start running and after
approximately 10 seconds, the ignition spark will
commence.

11. The sparking will continue until the pilot light
is established (Fig. 82) and then the main burner
will light from the pilot flame.

12. Check that both the main burner and the pilot
are alight by observing through the viewing
window. The indicator lights should also be
illuminated.

13. Should this sequence not occur, then refer to
the fault finding section of these instructions.

NOTE: The pilot rate for this appliance is
factory set, sealed and therefore non­adjustable.

*

Overheat

Boiler On

Fan On

Pilot On

Burner On

Overheat Neon
Warning

Gas Cock

Pressure Test
Point

Gas Valve

17 3

Fig. 79

Fig. 78

Fig. 82Fig. 81

Fig. 80

7.0 Commissioning the Appliance

33

7.1 Commissioning the Appliance (Cont)

1. The burner pressure is factory set.

2. From the table opposite check that the main
burner pressure is correct after the appliance has
been running for 10 minutes. If necessary,
adjustment to main burner pressure can be made
by altering the regulator as shown (Fig. 84).

3. Check for gas soundness, with main burner
alight, using leak detection fluid.

4. Turn the boiler thermostat to the OFF position
marked 0. Remove the pressure gauge and screw
home the pressure test point screw. Turn the boiler
thermostat knob to the required setting (Fig. 84).

5. The boiler and system should be run and then
flushed and treated in accordance with
BS 7593:1992 and the flushing agent / inhibitor
manufacturers instructions. Pressurise the system
to 1.0 bar then close and disconnect the filling
loop.

6. When all the air has been removed from the
water circuit, the pump and radiators should be
balanced to achieve the design temperature drop
across the system.

7. Make a final check for gas soundness and set
any timer control, room thermostats etc. to the
customer's specific requirements.

8. The boiler is protected by an integral frost-stat,
but if the boiler is not to be used for a long period
of time, the system should be drained.

NOTE: The frost thermostat operates even if
the boiler thermostat is in the OFF position and
it is necessary therefore, if the system is
drained, for the external electrical and gas
supplies to be isolated.

It is recommended that a label be affixed to the
appliance to draw attention to the fact that the
system has been drained.

WARNING - If the system is filled with very cold
water and the boiler lit, the action of the frost
protection thermostat will prevent the boiler
from shutting down before the water
temperature reaches 10°C.

9. Carefully read and complete all sections of the
“Benchmark” Installation, Commissioning and
Service Record Log Book that are relevant to the
appliance and installation. The details of the Log
Book will be required in the event of any warranty
work. The Log Book must be handed to the user
for safe keeping and each subsequent regular
service visit recorded.

Pressure Test Point

Gas Valve

Fig. 84

Fig. 83

Model

Input P Setting Pressure

kW Btu/h mbar in wg

30 10.99 37, 500 16.0

+

0.5 6.4 +0.2

40 14.65 50, 000 16.0

+

0.5 6.4 +0.2

50 18.32 62, 500 16.0

+

0.5 6.4 +0.2

60 21.98 75, 000 16.0

+

0.5 6.4 +0.2

70 25.64 87, 500 16.0

+

0.5 6.4 +0.2

80 29.31 100,000 16.0

+

0.5 6.4 +0.2

Regulator

8.0 Fitting the Outercase

34

8.1 Fitting the Outercase

1. The warning label may be removed unless the
boiler is to be fitted within a cupboard or
compartment.

2. If the appliance is flued to the left or to the
right, remove the relevant infill panel from the
case by removing the retaining clips and fixing
screws (Fig. 87).

3. Offer the outer case up to the wall plate.
Engage the slots in the case over the hooks on
the back plate. Ensure that the case is positively
located (Fig. 86).

4. Using the two screws previously removed,
secure the outer case to the combustion box
(Fig. 85).

5. Replace the lower front door panel, relocate
the door stay and hinge upwards, ensuring it is
secured by the two magnets (Fig. 87 & 88).

6. Instruct the user in the operation of the boiler
controls. Hand over the Users Operating,
Installation and Servicing Instructions and the
Log Book giving advice on the necessity of
regular servicing.

Securing Screw

Lower Front

Door Panel

Magnets

Hinge

Infill Panel

Hooks

Fig. 85

Fig. 86

Fig. 87

Fig. 88

Door Stay

9.0 Overheat Cut-off Device

35

9.1 Operation

1. The overheat cut-off device is of the manual
reset type and therefore it is important that the
user knows how to reset the control should it
ever operate.

NOTE: Cut-off is indicated by illumination of
the overheat neon light on the control box.

2. Hinge the lower door panel down (Fig 89).

3. To reset the boiler - Turn the boiler
thermostat control knob fully anti-clockwise to the
OFF position marked ‘0’ (Fig. 90). Wait ten
seconds, then turn the control knob clockwise to
the required thermostat setting. The red neon will
go out and the boiler will start automatically.

4. If the overheat cut-off operates repeatedly,
refer to the fault finding chart at the rear of this
booklet and investigate the cause.

*

Overheat

Boiler On

Fan On

Pilot On

Burner On

Overheat Neon
Warning

Fig. 90

Fig. 89

10.0Annual Servicing

36

10.1 Dismantling the Boiler

1. For reasons of safety and economy the boiler
should be serviced annually. ( For location of
British Gas service test point see Changing
Components section of these instructions).

2. Before servicing the boiler please read Section

1.3 Important Information.

3. After servicing, complete the relevant section of
the “Benchmark” Installation, Commissioning and
Service Record Log Book. This should be in the
possession of the user.

4. Isolate the gas and electrical supplies to the
boiler.

5. Open the hinged lower door panel and carefully
disengage the door stay. Remove the door by
opening it 90° and pulling forward (Fig. 93).

6. Remove the outer case from the boiler by
unscrewing the two screws and lifting the case
clear (Fig. 91).

7. Release the four latches retaining the
combustion box door and remove the door
(Fig. 95) .

8. Release the 5-pin electrical plug connecting the
pressure switch and fan (Fig. 94). Withdraw the
fan assembly by pulling forwards from the top
edge (Fig. 95).

Securing Screw

Fan Assembly

Combustion Box Door

Lower Front

Door Panel

Magnets

Hinge

Fig. 91

Fig. 92

Fig. 93

Fig. 94

Fig. 95

Door Stay

Flexible Tubes

10.0Annual Servicing

37

10.2 Cleaning the Combustion Box

1. Remove the burner assembly by pulling it
forward (Fig. 97).

2. Lightly brush any dirt from the top of the burner
blades and ensure that the ports are free from
obstruction.

3. Remove the baffle retaining clip and lift the
baffles from the heat exchanger (Fig. 95a & 96).

10.3 Cleaning the Heat Exchanger

1. The heat exchanger may be cleaned by
insertion of a thin metal strip e.g. a hack saw
blade or steel rule, from above or below, taking
care not to damage any insulation.

2. Clean the front and rear fin sections and
ensure that any blockages are cleared.

10.4 Cleaning the Burner Injector

1. Remove the injector which is screwed into the
burner feed manifold (Fig. 99).

2. Examine and clean carefully, then replace
ensuring that the copper washer is in position.
Tighten the injector fully.

10.5 Cleaning the Pilot

1. Disconnect the spark electrode lead at the
electrode (Fig. 100).

2. Unscrew the electrode from the manifold and
withdraw the electrode (Fig. 100).

3. Remove the right hand side insulation carrier
bracket by releasing the screw. Remove the side
insulation (Fig. 101).

4. Release the screw securing the pilot hood and
remove (Fig. 102).

5. Carefully remove the pilot injector (Fig. 102).
Examine and clean it as necessary. Do not use a
wire or pin to clean the injector orifice.

6. Examine the sealing washer (Fig. 102) and
replace if it is damaged in any way. Reassemble
in reverse order.

7. Replace all components in reverse order

ensuring that the flexible tubes from the fan
unit to the pressure switch are routed
correctly and that they are not kinked or
flattened (Fig. 95).

8. Check that the seal to the combustion box door
is good.

9. Re-commission the boiler before use, checking
for gas soundness and ensuring all controls are
working correctly.

10. Complete the relevant section of the
“Benchmark” Installation, Commissioning and
Service Record Log Book and hand it back to the
user.

Burner

Baffles

Baffle Retaining Clip

60, 70 and 80
Models Only

Fig. 99

Fig. 96

Fig. 95a

Fig. 97

Fig. 98

Fig. 101

Fig. 100

Fig. 102

Pilot Hood

Pilot Injector

Sealing Washer

Electrode

RH Side Insulation

Insulation Carrier

Bracket

11.0Changing Components

38

Centre
Pin

Retaining
Rivet

Fig. 106

Fig. 107

Fig. 108

Fig. 103

Fig. 105

Fig. 104

11.1 Changing Components

1. Before changing any components ensure that
the gas and electrical supplies are isolated.

2. Before changing any components please read
Section 1.3 Important Information.

3. Open the hinged lower door panel and carefully
disengage the door stay. Remove the door by
opening it 90° and pulling forward (see Fig.93).

4. Remove the outer case from the boiler by
unscrewing the two screws and lift the case clear.

11.2 Replacing the Circuit Board

1. Ensure that the electrical supply is isolated.

2. Undo the

1

/4turn screws and drop the facia

panel down (Fig. 104).

3. Remove the cover from the front of the controls
box (Fig. 103).

4. Release the supply and pump feed cables from
the cable clamps and unplug the connection
blocks from the circuit board (Fig. 105).

5. Remove the screw retaining the thermostat
control panel and slide the circuit board from the
box.

6. Carefully withdraw the centre pin from the
retaining rivet which then allows the retaining rivet
to be removed. Remove the thermostat control
panel (Fig. 106 & 107). (On reassembling ensure
the control panel is located over the retaining rivet
body before inserting the centre pin).

7. Disconnect the plugs from the sockets on the
circuit board (Fig. 108).

8. Replace new circuit board in reverse order
checking that the connections are correct as
shown in the diagram (See Electrical Connections
section 6.18 of these instructions) and that the
harness is retained in the strain reliefs.

11.3 Ignition Electrode (Fig. 109)

1. Disconnect the spark electrode lead at the
electrode.

2. Unscrew the electrode from the manifold and
withdraw the electrode.

3. Replace the new electrode in reverse order,
ensuring that the sleeving is pushed over the end
of the electrode.

Electrode

Fig. 109

British Gas Service
Test Point.

For use by B.G.
Personnel only

Facia Securing
Screws

Facia Panel

11.0Changing Components

39

11.4 Gas Valve (Fig. 110 & 111)

1. Undo the 1/4turn screws and drop the facia panel
down.

2. Disconnect the electrical connections from the
valve, noting their positions.

3. Undo the screw retaining the valve cover and
remove the cover.

4. Undo the nut on the valve feed pipe at the tap
rail. Carefully remove the washer for re-use.

5. Remove the screws securing the outlet adaptor
to the valve. If necessary pull the electrical box
forward to improve access.

6. Undo the screws retaining the valve mounting
bracket to the combustion box.

7. Manoeuvre the valve and feed pipe away from
the appliance, taking care not to lose the gasket.

8. Note the orientation of the feed pipe relative to
the valve. Remove the screws holding the feed
pipe flange to the valve.

9. Examine the gaskets and washers and replace
them if they are damaged in any way.

10. Transfer the mounting bracket to the new
valve.

11. Reassemble the new valve in reverse order of
dismantling, ensuring that the gaskets and washer
are correctly fitted.

12. Check burner pressure is 16mbar ± 0.5 (See
section 7.1 paragraph 2 if burner pressure needs
adjusting).

11.5 Thermostat Sensor (Fig.112 & 113)

1. Disconnect the two electrical tags from the
sensor.

2. Prise the clip and sensor off the flow manifold.

3. Clip the new sensor to the pipe and reconnect
the wires. Either wire can be connected to either
spade terminal - there is no polarity.

11.6 Over-Heat Thermostat

(Fig.112 & 113)

1. Disconnect the two electrical tags from the
overheat thermostat.

2. Remove the two screws securing the thermost
to the pipe.

3. Ensure the thermostat mounting plate is clean
and free of debris. Fit the new thermostat using the
screws previously removed.

4. Connect the two electrical tags to the terminals
on the overheat thermostat - either wire can be
connected onto either terminal - there is no
polarity.

Fig. 113

Overheat
Thermostat

Flow Pipe

Orange Leads

Yellow Leads

Valve Feed Pipe

Outlet
Adaptor

Gasket

Valve

Valve Mounting Bracket

Gasket

Valve Cover

Fig. 111

Fig. 112

Fig. 110

Regulator - Turn in
either direction to adjust
burner pressure

Thermostat
Sensor

Thermostat
Mounting
Plate

11.0Changing Components

40

11.7 Changing Components (Cont)

1. To change Fan - Pressure Switch - Burner ­Burner Injector - Pilot Burner Injector - Gas
Manifold, proceed as follows:-

2. Release the four latches holding the combustion
box door. Remove the combustion box door by
pulling forward from the bottom and unhooking its
top edge (Fig. 115).

3. Disconnect the 5-pin pressure switch and fan
plug (Fig. 114). Withdraw the fan assembly by
pulling forwards from the top edge (Fig. 115).

11.8 Fan (Fig. 116)

1. Disconnect the two flexible tubes from the
venturi situated on the fan.

2. Disconnect the 2 fan wires from the connection
on the electrical plug. Remove the 3 screws
securing the fan to the fan hood.

3. Remove the two screws securing the fan outlet
flange to the fan and remove. Clean all sealing
mastic from the outlet flange.

4. Fit the outlet flange onto the new fan, fix with the
2 screws and seal the outside gap between the fan
body and the outlet fan with the mastic provided.

5. Fit the new fan and re-assemble all components
in reverse order of dismantling ensuring that the
flexible tubes from the fan unit to the pressure
switch are routed correctly and that they are not
kinked or flattened (Fig. 115), reconnect the new
fan wires into the connections on the electrical plug

- either wire can be connected into either
connection.

11.9 Pressure Switch (Fig. 117)

1. Disconnect flexible tubes noting their positions.

2. Remove the screw securing the pressure switch
to its bracket and unhook the pressure switch.

3. Disconnect the 3 electrical terminals from the
pressure switch. Note the position of the tags
before removal and reconnect in correct order.

4. Fit new pressure switch and re-assemble all
components ensuring that the flexible tubes from
the fan unit to the pressure switch are routed
correctly and that they are not kinked or flattened
(Fig. 115). Ensure that the electrical terminals are
connected to their correspondingly marked tags.

Fig. 116

Fig. 115

Fig. 114

Fig. 117

Outlet Flange

Flexible Tubes

Flexible Tubes

Grey

Pressure Switch

Fan

Flexible Tubes

Black

White

Fan

Assembly

Combustion Box Door

11.0 Changing Components

41

11.10 Burner (Fig. 118)

1. Remove the burner assembly by pulling it
forward.

2. Fit new burner and re-assemble all components
in reverse order of dismantling.

11.11 Burner Injector (Fig. 120)

1. Release and remove the burner injector which
is screwed into the burner feed manifold.

2. Fit the new burner injector ensuring that the
copper washer is in position. Tighten the injector
fully.

3. Re-assemble all components in reverse order.

11.12 Pilot Burner Injector (Fig. 121)

1. Remove the right hand side insulation carrier
bracket by releasing the screw. Remove the side
insulation panel (Fig. 122).

2. Release the screw securing the pilot hood and
remove. Carefully remove the pilot injector. Fit the
new pilot injector ensuring the new sealing washer
is in position. Tighten the injector fully.

3. Re-assemble all components in reverse order.

11.13 Gas Manifold (Fig. 123)

1. Undo the 1/4turn screws and drop the facia
panel down.

2. Pull the electrode lead off the electrode.

3. Remove the right hand side insulation carrier
bracket by slackening the screw. Remove the
burner. Remove the side insulation panel
(Fig. 122).

4. Undo the three screws securing the brass inlet
adaptor to the manifold.

5. Remove the two screws securing the manifold
from the inside of the combustion box and slide
the manifold forward from under the two rear
locating studs, taking care not to lose the gasket.

6. Remove the electrode

7. Replace all ancillary components onto manifold
and replace manifold by sliding rear edge
backwards under the two rear locating studs and
securing from inside the combustion box using the
two screws previously removed. Ensure that the
sealing gasket is properly positioned and
undamaged.

Burner

60, 70 and 80
Models Only

Fig. 120

Fig. 118

Fig. 119

Fig. 121

Fig. 123

Pilot Hood

Pilot Injector

Sealing Washer

Gas Manifold

Electrode

Electrode Lead

Inlet Adaptor

Fig. 122

RH Side Insulation

Insulation Carrier

Bracket

11.0 Changing Components

42

11.15 Pump (Head Only) (Fig. 128)

1. If only the head needs replacing. A standard
Grundfos UPS 15-60 pump head is
interchangeable.

2. Isolate the appliance from the water system by
closing the flow and return taps.

3. Drain the boiler of water.

4. Undo the

1

/4turn screws and drop the facia

panel down.

5. Unplug the wiring harness from the pump.

6. Remove the four socket head screws securing
the pump head and separate it from the housing.

7. Check that the new pump has been switched to
setting N

o

3.

8. Remove the screws retaining the pump
electrical covers on the original and replacement
heads.

9. From the replacement UPS 15-60 pump head
remove the strain relief cable gland and discard.

10. Remove the plug connector from the old pump
head and wire it into the UPS 15-60 pump head.

11. Replace the electrical cover to the new pump
head and assemble with the electrical box at
6 o’clock to the housing.

12. Reconnect the wiring harness plug

13. Repressurise and recommission the system.

11.16 Pump (Complete) (Fig. 125 & 127)

1. Isolate the appliance from the water system by
closing the flow and return taps.

2. Drain the boiler of water.

3. Undo the

1

/4turn screws and drop the facia

panel down.

4. Unplug the wiring harness from the pump.

5. Remove the four screws retaining the pump
backplate to the hydraulic manifold.

6. Remove the pump.

7. Fit the new pump and reassemble in reverse
order.

8. Repressurise and recommission the system.

Pump Setting

Fig. 125

Fig. 127

Fig. 128

Fig. 126

Facia Panel

Facia Securing

Screws

Fig. 124

11.0 Changing Components

43

11.16 Pressure Gauge

1. Isolate the appliance from the water system by
closing the flow and return taps.

2. Drain the boiler of water.

3. Undo the

1

/4turn screws and drop the facia

panel down.

4. Undo the nut on the gauge capillary at the
boiler flow connection (Fig. 131).

5. Press in the two lugs on the gauge body, and
pass the gauge and capillary through the facia
(Fig. 130).

6. Fit the new gauge in reverse order and
recommission the appliance.

11.17 Pressure Relief Valve (Fig. 129)

1. Isolate the appliance from the water system by
closing the flow and return taps.

2. Drain the boiler of water.

3. Undo the

1

/4turn screws and drop the facia

panel down.

4. Undo the nut on the pressure relief pipe and
slacken the screw holding the valve to the
manifold.

5. Fit the new valve in reverse order and
recommission the appliance.

11.18 Re-pressurising Expansion Vessel

1. The charge pressure is 1.0 bar.

2. Close the central heating flow and return
isolating valves.

3. Drain the boiler of water.

4. The expansion vessel valve is situated to the
right of the combustion box, below the expansion
vessel.

5. Pressurise to 1.0 bar.

6. Open the isolating valves and recharge the
system to 1.0 bar.

7. Vent the system as necessary.

Fig. 131

Fig. 129

Lug

Capillary

Return Pipe

Pressure
Relief Valve

Pressure Gauge

Fig. 130

44

12.0Short parts list

27

26

86

122

17

16

18

32

88

97

121

71

72

101

14

44

87

12.1 Short Parts List

18

Key Description Model G.C. Manuf'rs
N

o

N

o

Part N

o

44 Burner 30, 40, 50 364 878 231708

60, 70, 80 364 879 231709

27 Burner Injector 30 246176

40 246177

50 246178

60 246161

70 246162

80 246163

26 Pilot Kit All models 170 558 236142

122 Electrode Lead All models 246200

86 Control Knob All models 364 886 230981

14 Viewing Window Kit All models 364 588 224183

101 Pressure Switch 30, 40, 50 246053

60, 70 246054

80 E26 221 246055

17 Insulation R.H. All models 364 889 230653

16 Insulation L.H. All models 364 980 230652

18 Retaining Clip All models 364 891 230817

32 Gas Valve All models E24 690 245122

72 Overheat Thermostat All models 5106746

121 Fuse All models 364 892 231402

97 Fan 30, 40, 50 246051

60, 70, 80 246052

71 Thermostat All models 246064

88 Control Board All models 379 031 231711

87 Potentiometer All models 379 960 231252

79 Pump All models E02 762 241157

93 Pressure Gauge All models E02 796 241190

73 Automatic Air Vent All models E02 759 241154

73

93

79

13.0Fault Finding

45

START

Replace fan

Replace harness

Replace pressure

switch

Replace fan

Replace

thermostat

Does fan run ?

Is

there a clear

constant spark at

the electrode ?

Change

potentiometer

Is

there mains voltage

at S/L input ?

Is

there mains voltage

at Pump L output ?

Check fuse on

circuit board

Check pump wiring

Note: This can occur if

the boiler has

overheated

Reset by turning

control knob OFF, wait

10 seconds then turn

ON

Does

lockout light

go out ?

Is
"Fan On"
light on ?

Check control knob

is turned on

Check that the wires

are connected to the

thermostat sensor

Check that the fan &

pressure switch plug is

connected

Is there

continuity between

C & NC terminals

on the pressure

switch ?

Check pressure switch

pipes for leaking or

blockage

Note: Under cold

conditions fan run up

time may exceed

1 min

Ensure external

controls are calling

for heat

Does pump run ?

Is
"Pilot On"
light on ?

Is

lockout light

on ?

Is

"Boiler On"

light on ?

Is

there mains voltage

at P/L input ?

Is

there mains at

the fan

connection ?

Is there

continuity across

the overheat
thermostat ?

YES

NO

YES

YES

YES

YES

YES

NO

YES

YES

NO

NO

NO

NO

NO

YES

YES

YES

NO

NO

NO

NO

YES

NO

No continuity - change

sensor

Check continuity

across pilot solenoid

(1.5 K OHM)

No continuity - change

pilot solenoid

Check continuity

across sensor

(1 M OHM at 20oC)

Investigate

pump

Change PCB

No continuity

across fuse,
change fuse

YES

YES

Change PCB

Check & clean

electrode. Check gap &

lead

YES

Check external

wiring

NO

Check Potentiometer

(see table)

Before starting FAULT FINDING carry out preliminary
electrical system checks i.e. Earth Continuity, Polarity,
Short Circuit and Resistance to Earth. Ensure that the
system is correctly pressurised.

13.0Fault Finding

46

Replace the gas

valve

Replace PCB

Boiler satisfactory

Set burner pressure

to 16mbar ± 0.5

Does

the pilot burner

light ?

Does

the main burner

light ?

Does

the boiler shut

down when the water

flow reaches

80-84oC ?

Does

pump run

on ?

Is

"Burner On"

light on ?

Are live &

neutral reversed ?

Indicator light inside

box will be lit

Check pilot flame

for correct size

Check & clean

electrode. Check spark

gap. Check electrode

lead

Check there is

20mbar gas pressure

at the inlet to gas valve

Check there is

20mbar gas pressure

at the inlet to gas valve

Check the pilot injector is

not blocked, partially
blocked or damaged

Check there is

20mbar gas pressure

at the inlet to gas valve

Is

there the

correct burner

pressure at the test

point ?

YES

YES

YES

YES

YES

NO NO

NO

NO

NO

Check pilot injector is

not blocked

Check main injector

is not blocked

Warning

It is important that both the air and flue ducts are
cut to their correct lengths also ensure that the
flue duct is fully engaged.

Failure to comply with the recommended fitting
instructions will adversely affect the operation of
the appliance.

Check pilot flame

size

YES

YES

YES

YES

Check pilot hood
position and pilot

air flow

Check continuity

across mains solenoid

(5 K OHM)

Change gas valve

NO

Change PCB

YES

Testing Potentiometer

Three Pin Connector

Set multimeter to the 2 M OHM
scale. Turn potentiometer to the
OFF position, connect the
multimeter leads to the blue/red wire
and centre black/yellow wire of three
pin connector.

The reading on the multimeter
should indicate approx 1 M OHM,
switch potentiometer to the ON
position, the reading on the
multimeter should be approx 1 M
OHM. Slowly turn potentiometer
knob to the FULL ON position, the
reading on the multimeter should
decrease, proportionally down to 0
OHMs.

Connect multimeter to centre
black/yellow wire and red/yellow
wire, turn potentiometer knob to fully
OFF position, reading on multimeter
should be 0 OHM. Switch
potentiometer to ON position, slowly
turn potentiometer knob to the fully
ON position, the reading on
multimeter should increase
proportionally to 1 M OHM, turn
potentiometer off. Reading on
multimeter should indicate 0 OHM.

Two Pin Connector

Check potentiometer is in OFF
position.

Set multimeter to continuity, connect
multimeter leads to both
potentiometer leads. Turn
potentiometer to the on position, the
multimeter's audible alarm should
now be sounding to indicate
continuity.

Replace PCB

Replace sensor

Check

Potentiometer

(see table)

47

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

Technical Enquiries

08706 049 049

Comp No5106278 - Iss 1 - 11/01