Baxi Solo 2 PF Quick Start Manual

BaxiSolo 2 PF

Wall Mounted Powered Flue
Gas Fired Central Heating Unit

Installation and
Servicing Instructions

Please leave these instructions with the user

2

Baxi Heating Ltd 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
consumers, 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.

Baxi is also the largest manufacturing partnership in
the country. Everyone who works at the company
has a commitment to quality because, as
shareholders, 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 2 30 PF

G.C.No. 41 077 71

Baxi Solo 2 40 PF

G.C.No. 41 077 72

Baxi Solo 2 50 PF

G.C.No. 41 077 73

Baxi Solo 2 60 PF

G.C.No. 41 077 74

Baxi Solo 2 70 PF

G.C.No. 41 075 01

Baxi Solo 2 80 PF

G.C.No. 41 077 75

Baxi is a BS-EN ISO 9001
Accredited Company

The boiler meets 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
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.

3

1.0 Introduction 4

2.0 Technical Data 5

3.0 System Details 7

4.0 Site Requirement 10

5.0 Installation 13

6.0 Commissioning the Appliance 31

7.0 Fitting the Outercase 33

8.0 Overheat Cut-Off Device 34

9.0 Annual Servicing 35

8.0 Changing Components 37

9.0 Short Parts List 41

10.0 Fault Finding 42

Section Page

Contents

1.0 Introduction

4 1

STANDARD
B.S. 6891
B.S. 5546

B.S. 5449
B.S. 6798

B.S. 5440: Pt 1
B.S. 5440: Pt 2

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.

HEAT OUTPUT

Model Min Max

30 5.86kW (20,000 Btu/h) 8.79kW (30,000 Btu/h)
40 9.09kW (31,000 Btu/h) 11.72kW (40,000 Btu/h)
50 12.02kW (41,000 Btu/h) 14.65kW (50,000 Btu/h)
60 14.95kW (51,000 Btu/h) 17.58kW (60,000 Btu/h)
70 17.88kW (61,000 Btu/h) 20.5kW (70,000 Btu/h)
80 20.8kW (71,000 Btu/h) 23.45kW (80,000 Btu/h)

B.S. Codes of Practice

1.1 Description

1. The Baxi Solo 2 PF is a gas fired room sealed
fan assisted central heating boiler with range rated
outputs as shown in the table below

2. Each appliance is preset at a MID

RANGE heat
input rating and is designed for use on NATURAL
GAS only.

3. All boilers are suitable for fully pumped open
vented central heating and domestic hot water
systems and sealed systems.

4. The appliance data badge is fitted to the
combustion box door.

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 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 3.1).

1.3 Important Information

This product contains Refractory Ceramic Fibres
(R.C.F.) which are man-made vitreous silicate
fibres. Excessive exposure to these materials may
cause tempory irritation to eyes, skin and
respiratory tract. Care must be taken when
handling these articles to ensure the release of
dust or fibres is kept to a minimum.
To ensure that the release of fibres from these
articles is kept to a minimum, during installation
and servicing it is recommended that a H.E.P.A.
filtered vacuum is used to remove any dust, soot
or other debris accumulated in and around the
appliance. This should be performed before and
after working on the installation.
It is recommended that any replaced item(s) are
not broken up but sealed within heavy duty
polythene bags and clearly labelled “R.C.F.
waste”. This is not classified as “hazardous waste”
and may be disposed of at a tipping site licensed
for the disposal of industrial waste.
Protective clothing is not required when handling
these articles but it is recommended that gloves
are worn and the normal hygiene rules of not
smoking, eating or drinking in the work area are
followed and always wash hand

s before eating or

drinking.

2.0 Technical Data

1 5

Model 30 40 50 60 70 80

Heat Output (Max) kW 8.9 11.72 14.65 17.58 20.5 23.45

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

Heat Output (Min) kW 5.86 9.09 12.02 14.95 17.88 20.8

Btu/h 20,000 31,000 41,000 51,000 61,000 71,000

Heat Input (Max) 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

Heat Input (Min) kW 7.33 11.36 15.02 18.68 22.35 26.01

Btu/h 25,000 38,750 51,250 63,750 76,250 88,750

Burner Pressure (Max) 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

Burner Pressure (Min) mbar 8.0 ±0.5 10.0 ±0.5 11.5 ±0.5 11.5 ±0.5 12.1 ±0.5 11.5 ±0.5

in wg 3.2 ±0.2 4.0 ±0.2 4.4 ±0.2 4.4 ±0.2 4.8 ±0.2 4.4 ±0.2

Gas Rate CV 38MJm31.04m3/h 1.39m3/h 1.74m3/h 2.08m3/h 2.78m3/h 2.78m3/h

(after 10 mins) 36.86ft3/h 49.0ft3/h 61.3ft3/h 73.5ft3/h 98.1ft3/h 98.1ft3/h

Lifting Weight kg 23.1 23.1 23.1 32.2 32.2 34.2

lbs 51 51 51 71 71 75.5

Water Content litres 1.1 1.1 1.1 1.6 1.6 1.3

pints 1.9 1.9 1.9 2.8 2.8 2.3

Outercase Height 600mm 600mm 600mm 600mm 600mm 600mm

Dimensions Width 350mm 350mm 350mm 462mm 462mm 462mm

Depth 287mm 287mm 287mm 287mm 287mm 287mm

Flue Terminal Diameter 100mm

Dimensions Depth 65mm

Static Head Max 30 metres (100 ft)

Min 1 metres (3.25 ft)

Connections Flow 22mm Cu tail

Return 22mm Cu elbow

Heat Exchanger Cast iron monobloc

Low Head Min 0.2m (8 in)

System Design fully pumped open vented and sealed systems

Gas Connection RC1/2(1/2in BSPT)

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

Controls boiler thermostat, pilot & electronic flame sensing, timed pump over-run,

frost protection thermostat

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

2.0 Technical Data

6

Layout of Fixing Points
30, 40 and 50 PF models

25

75

121

392

439

442

380

196196

52

107 Dia
without
internal
fitting

117 Dia
with
internal
fitting

Centre of
Gas Connection

8 Slots
20 x 6

Layout of Fixing Points
60, 70 and 80 PF models

287mm

300mm for servicing

5mm during operation

5mm350mm (30,40,50 models)5mm

100mm

600mm

50mm

462mm (60,70,80 models)

(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 10121416182022

Water Flow Rate litres / min

Pressure Drop mbar (in wg)

24262830

(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 10121416182022

Water Flow Rate litres / min

Pressure Drop mbar (in wg)

24262830

(52) 130

30, 40 and 50 PF models

60, 70 and 80 PF models

Clearances

Templates

Hydraulic Resistance Charts

268

107 Dia
without
internal
fitting

Centre of
Gas Connection

117 Dia
with
internal
fitting

4

144144

25

392

8 Slots
20 x 6

75

439

121

442

3.0 System Details

7

Typical Systems
Arrangement

Option A

Boiler

Pump

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. 1

Fig. 2

Fig. 3

Fig. 4

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. 3).

c) A system using a 3 port divertor valve
(Fig. 4) 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.

The bypass circuit can be:-

a) For 30/40/50 PF a minimum of 8 metres
of 22mm pipe, for 60/70/80 PF a minimum
of 8 metres of 28mm pipe (measured
between the boiler flow and return
connections). It should be fitted with a lock
shield valve opened at least 1 full turn to
give a minimum flow rate of 8 litres/min (1.8
gal/min) (Option C, Fig. 1 & Option A,
Fig.2).

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 cm

2

(4 sq ft) is adequate (Option B,

Fig. 1).
c) Any circuit that provides the same

operating conditions as option A or option B
(Figs. 1 & 2).

3.1 Water Circulating Systems

1. The appliance is suitable for use with open
vent fully pumped systems, sealed systems and
where additional control protection is required.

The following conditions should be observed
on all systems:

• The static head must not exceed 30m (100ft) of
water.

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

• The boiler is fitted with a timed pump overrun that
will operate for approximately 8 minutes.

• 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.

• Position isolating valves as close to circulating
pump as possible.

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 5793:1992 “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 5793:1992.

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.

3.2 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.

3.0 System Details

8

3.3 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. An 11 °C (20°F) drop in temperature across the
system is recommended.

3.4 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.

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

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

5. A frost thermostat is fitted integrally to the
appliance controls and will protect the boiler from
frost damage by operating the burner when the
water temperature in the boiler drops towards
freezing point. The boiler will fire as necessary to
maintain a temperature above freezing.

NOTE: The frost thermostat operates even if
the boiler thermostat is in the OFF ('0') 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.

3.5 Low Head Installation

For boilers up to 50,000 Btu/h output

1. Using a close couple arrangement the minimum
head is as shown in the diagrams (Figs. 5 & 6)
subject to the following conditions:

a) The correct heat input.
b) The pump being adjusted to give an 11

o

C

drop across the boiler.
c) The pump must be fitted on the flow.
d) The pump must be fitted in accordance with

the pump manufacturer's instructions.
e) The open vent pipe must be taken up from a

tee in a horizontal section of the flow pipe.

Alternative Low Head Installation for all Solo 2 PF

(Fig. 7)

2. If less height is available then a combined vent
and feed pipe may be connected. This must be a
minimum of 22mm diameter. It is recommended
that an air separator is fitted when using a
combined feed and vent pipe.

Typical Low Head Installation

If Conditions Require,

This System Possible

Alternative Low Head Installation

Boiler

500mm

45°

22mm
Open Vent

1000mm

Min

150mm

Max

15mm
Cold
Feed

400mm

Min Head

Return

Pump

Flow

Boiler

500mm

45°

22mm
Open Vent

400mm

Min Head

1000mm

Min

Automatic

Air Vent

15mm
Cold
Feed

150mm

Max

Return

Pump

Flow

Return

Pump

Flow

Boiler

200mm

Min

Air

Separator

22mm
Feed & Vent
Pipe

Fig. 5

Fig. 6

Fig. 7

3.0 System Details

9

3.6 Sealed Systems (Fig. 8)

1. SAFETY VALVE - A safety valve complying
with the requirements of BS 6750 Part 1 must be
fitted close to the boiler on the flow pipe by means
of a horizontal or vertically upward connection
with no intervening valve or restrictions and
should be positioned to facilitate testing. The
valve should be pre-set and non-adjustable to
operate at a pressure of 3 bar (45 Ibf/in

2

). It must
be arranged to discharge any water or steam
through a pipe to a safe outlet position.

2. PRESSURE GAUGE - A pressure gauge of
minimum range 0-4 bar (0-60 Ibf/in

2

) with a fill
pressure indicator must be fitted to the system,
preferably at the same point as the expansion
vessel in an easily visible position.

3. EXPANSION VESSEL - An expansion vessel
complying with the requirements of BS 4814 must
be fitted to the system by means of a connection
close to the inlet side of the circulating pump in
accordance with the manufacturers instructions,
the connecting pipe being unrestricted and not
less than 15mm (

1

/2in) nominal size. The volume
of the vessel should be suitable for the system
water content and the nitrogen or air charge
pressure should not be less than the system static
head (See Table. 1).

Further details of sealed system design can be
obtained from BS 5449 and the British Gas
publication entitled 'Specifications for Domestic
Wet Central Heating Systems'.

4. FILLING POINT - A filling point and an
approved stop valve to BS 1010 must be fitted at
low level and the method used for filling the
system should be approved by the local water
undertaking. For further details see BS 6798.

5. MAKE UP SYSTEM - A method of replacing
water lost from the system should be provided
either by means of a make up vessel of not more
than 3 litres (5 pints) capacity, mounted above the
highest point of the system, or by pre­pressurisation of the system.

6. VENTING - A method of venting the system
during filling and commissioning must be provided
by fitting automatic air vents or by venting
manually.

7. HOT WATER STORAGE - The hot water
storage vessel must be of the indirect coil type. 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.

Initial System
Pressure (Bar)

Vessel Charge
Pressure (Bar)

Multiply Total
Water Content Of
System By (Litres)

0.067

0.112

0.207

0.441

0.087

0.152

0.330

0.125

0.265

0.5

1.0

1.5

2.0

1.0

1.5

2.0

1.5

2.0

0.5

1.0

1.5

Example :-

Then :-

System Volume = 75 litres
Vessel Charge Pressure = 1.0 bar
Initial System Pressure = 1.5 bar
75 x 0.152 = 11.4 litres
Expansion Vessel Volume

Method of determining minimum

value of expansion vessel volume for

sealed systems using Baxi Boilers

NOTE

Where a vessel of the calculated size is not obtainable

then the next available larger size should be used.

Safety

Valve

Pressure

Gauge

Pump

Filling

Point

Air

Vent

3 Litre
Top Up Bottle
(if required)

Radiator
Circuit

Expansion
Vessel

System Drains
at Low Point

Max Boiler Flow

Temp = 82° C

Boiler

Fig. 8

Table. 1

4.0 Site Requirements

10

4.1 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 (Fig. 9). 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 4.5.)

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
British Gas document DM2.

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

4.2 Clearances (Fig. 10)

1. A flat vertical area is required for the installation of
the boiler measuring as shown in the table below for
each model.

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 300mm
shown is only necessary when the cupboard door is
open. A clearance of 5mm (

3

/16in) is required when

the door is closed.

4.3 Flue Position

1. For installations where the flue terminal is
inaccesible 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. 11).

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.

Aluminium
Shield

600

A

50

100

5

5

300

Model A

30

350

40 350
50 350
60 462
70 462
80 462

Model

Height Width
mm (in) mm (in)

30 750 (291/2) 360 (141/8)
40 750 (291/2) 360 (141/8)
50 750 (291/2) 360 (141/8)
60 750 (291/2) 472 (185/8)
70 750 (291/2) 472 (185/8)
80 750 (291/2) 472 (185/8)

Fig. 9

Fig. 10

Fig. 11

4.0 Site Requirements

11

4.3 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 Heating Ltd 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. Table 2 and the accompanying diagram show
the positioning of the flue terminal relative to
buildings and other structures.

7. The dimensions of the flue terminal are shown
in Fig. 12.

4.4 Flue Dimensions

1. The standard flue supplied with the appliance
is suitable for use with flue lengths between
100mm (4in) and 685mm (27in).

NOTE: Maximum flue length when flued to the
left or right is

584mm (23in) - 30, 40, 50 PF
533mm (21in) - 60, 70, 80 PF

2. Flue extension kits are available as an optional
extra for installations up to 1 metre
(39

3

/8in) and up to 2 metres (793/4in). 2 metre kit

is not available for the 70 and 80 PF model.

3. A vertical flue kit, with flue breaker, is also
available as an optional extra (Sol-Ver Kit).

4. Where it is intended to pass the flue through a
combustible wall or timber framed dwelling,
reference should be made to British Gas
publication DM2.

5. If the flue is more than 1.8 metres (70

7

/8in)

long, it is required that it is supported.

6. All above dimensions are taken from the

respective faces of of the outer case.

D

A

F

F

G

B,C

A
G

E

G

J

K

D

L

H,I

Likely positions requiring
a flue terminal guard

65

100

Table. 2

Fig. 12

Flue Terminal Dimensions

Terminal Position with Minimum Distance (mm)

A Directly below an openable window or other

opening, e.g. an air brick. 300
B Below gutters. 25
C Below eaves, soil pipes or drain pipes. 75
D Below balconies or car port roof 200
E From vertical drain pipes and soil pipes. 75
F From internal or external corners. 25
G Above ground, roof or balcony level. 300
H From a surface facing a terminal. 600
I From a terminal facing a terminal. 1200
J Vertically from a terminal on the same wall. 1500
K Horizontally from a terminal on the same wall. 300
L For an opening in a car port (e.g. door, window)

into a dwelling. 1200

4.0 Site Requirements

12

4.5

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.
The Solo 2 PF will run sufficiently cool without
ventilation.

4.6 Gas Supply (Fig. 13)

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

2. The connection of the appliance is a RC

1

/2(1/

2

in BSPT internal) located at the rear of the gas
cock.

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 appliance gas
connection.

4.7 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. 13

5.0 Installation

13

5.1 Initial Preparation

1. Unpack contents of carton.

2. Remove the lower door panel from the outer
case. Remove the 2 screws holding the outer
case to the combustion box.

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

4. Release the R clips from the two latches
securing the combustion box to the back plate
and release the latches (Fig. 14).

5. Lift and remove the combustion box from the
back plate (Fig. 15). Place the combustion box
on its back.

IMPORTANT - When installing a Solo 2 with
a rear flue see section 5.2 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
above the standard 610mm (24 in) the
relevant optional extra kits must be obtained
and their instructions followed.

Fig. 14

Fig. 15

5.0 Installation

14

5.2 Fan Outlet Restrictor

(30, 40, 50, 60, 70 and 80)

Rear Flue only up to 686mm (27 in)

1. Release the four latches holding the
combustion box door (Fig 16a). Remove the
combustion box door by pulling forward from the
bottom and unhooking its top edge (Fig. 16).

2. Release the 5-pin electrical plug connecting
the pressure switch and fan (Fig. 17). Withdraw
the fan assembly by pulling forwards from the
top edge (Fig. 16).

3. Take the sheetmetal 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 over the flange to
secure (Fig. 18).

5. Re-assemble the fan assembly and
combustion box door.

Fan Outlet Flange

Fan Outlet Restrictor

Fig. 17

Fig. 16a

Fig. 16

Fig. 18

5.0 Installation

15

5.3 Position the Boiler (Fig. 19)

1. Choose a suitable position for the boiler
making necessary allowances for the minimum
clearances required as shown in the table below.

2. Hold the wall template against the wall at the
required boiler location. Ensure that the top of
the template is level (Fig. 20).

3. The template represents the outer limits of the
appliance plus the required minimum side
clearance.

4. Mark the position of the flue hole centre and
the inward pointing corners of the two triangular
cutouts in the template. Mark the position of the
four fixing holes. Where possible use the
uppermost and lowest fixing hole positions,
otherwise space the fixing holes as far apart as
possible (Fig. 20).

5.4 Rear Flue

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 quoting Baxi
Part N

o

226441.

2. If using the internal fitting kit a 117mm

(4

5

/8in) diameter hole is required.

3. Drill the anchorage holes 63mm (2

1

/2in) deep

to accept suitable wall plugs (Fig. 21).

4. Using the previously marked flue hole centre,
cut a hole approximately 107mm (4

1

/4in)
diameter in the masonry for the 100mm (4 in)
diameter flue duct. (When using a core drill, it is
important to keep the drill level and square).

750

100

A

50

Model A

30

360

40 360
50 360
60 472
70 472
80 472

Fig. 19

Fig. 20

Fig. 21

5.0 Installation

16

5.5 Rear Flue Preparation

1. Measure the wall thickness (Fig. 22) and to this
dimension add 60mm (2

3

/8in).

2. Take the flue duct and mark off wall thickness
+ 60mm (2

3

/8in) from the swaged end of the duct
and cut to size (Fig. 23). (Use the tape provided
to give an accurate cutting guide by wrapping it
around the flue duct with the edge marking the
cutting line).

3. Wall Thickness 280mm - 685mm
(11in - 27in) -Take the telescopic air duct from its
pack. Open the air duct out to the wall thickness.
Using the tape provided seal the joints of the
three sections of the air duct, ensuring an overlap
of at least 30mm (1

3

/16in) at each joint (Fig. 24).

NOTE: The seams of all three sections must
be in line.

4. Wall Thickness 100mm - 280mm (4in - 11in)
If the wall thickness is less than 280mm (11 in), it
will be necessary to cut the components of the air
duct to the appropriate size. Dispose of the centre
section, as this is not required (Fig. 25).

5. Measure the wall thickness and subtract 30mm
(1

3

/16in) from this dimension. Cut the remaining
sections to this length, measuring from the
positions indicated in the diagram (Fig. 25).

6. Engage the sections, one inside the other, then
open the assembly out to wall thickness. Tape the
sections together using the tape provided,
ensuring that the seal is good (Fig. 26).

NOTE: The seams of both sections must be in
line.

Wall Thickness + 60mm

Wall Thickness - 30mm

Wall Thickness - 30mm

Wall Thickness

Fig. 22

Fig. 23

Fig. 24

Fig. 25

Fig. 26

5.0 Installation

17

5.6 Assembly of Rear Flue

1. Remove the rear air box blanking plate from
the back plate by releasing the three screws
(Fig. 27).

2. Remove the blanking cap at the rear of the
turret, by pushing and turning anti-clockwise to
release the bayonet fitting (Fig. 28).

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. 29).

4. Ensure all seams of the air duct sections are
uppermost and 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 back plate, ensuring that the flue
duct locates into position in the terminal end of
the air duct.

6. 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 back plate (Fig. 30).

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

Fig. 27

Fig. 28

Fig. 29

Fig. 30

Rear Air Box
Blanking Plate

Blanking Cap

Flue Duct

Air Duct

5.0 Installation

18

5.7

Fitting the Back Plate

1. Engage the assembly into the hole previously
cut in the wall and slide in place (Fig. 31).

2. Secure the assembly to the wall at the
previously drilled anchorage points with suitable
screws (Fig. 31). 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. 32).

4. The flue trim provided may be fitted if required,
to neaten up the make-up around the terminal.
This plate may also be used as a protection plate
on outside walls of combustible material.

5. Fit the trim over the flue terminal and mark
through the four securing holes. Remove the trim,
drill holes 63mm (2

1

/2in) deep to accept suitable
wall plugs. Fit the trim over the flue terminal and
secure using suitable screws (Fig. 33).

Fig. 31

Fig. 32

Fig. 33

5.0 Installation

19

5.8 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. 30-40-50 PF - Left/Right Hand Side maximum
flue 584mm (23 in).

3. 60-70-80 PF - Left/Right Hand Side maximum
flue 533mm (21 in).

4. Using the previously marked flue hole centre
and the two marks made at the triangular cutouts
of the template, mark the horizontal centre line for
the flue assembly (Fig. 34).

5. Extend this line either left or right as required,
to the corner of the room (Fig. 34).

6. 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. 35).

7. From the wall template remove the detachable
section outlined and marked. Using this as a
template, 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. 36).

8. 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.

9. 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. 37).

10. 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. 38).

11. 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.

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

5

/8in)

diameter hole is required.

13. Cut a hole approximately 107mm (4

1

/4in)
diameter in the masonry for the 100mm (4 in)
diameter flue duct (Fig. 39). (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).

14. Drill the anchorage holes 63mm (2

1

/2in) deep

to accept suitable wall plugs.

Fig. 34

Fig. 35

Fig. 36

Fig. 37

Fig. 38

Fig. 39

5.0 Installation

20

5.9 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
distance R (Fig. 40).

2. Measure the thickness of the wall from the
inside. This will be known as distance W (Fig 41).

3. Add these two figures together plus 168mm
(6

5

/8in) for 30-40-50 PF and 224mm (87/8in) for

60-70-80 PF

4. 30-40-50 PF:

Flue Duct Length = R + W + 168mm (6

5

/8in)

5. 60-70-80 PF:

Flue Duct Length = R + W + 224mm (8

7

/8in)

6. Mark off the appropriate length from the
swaged end of the flue duct. Cut the duct to
length and dispose of the unwanted length. (Use
the tape provided to give an accurate cutting
guide by wrapping it around the flue duct with the
edge marking the cutting line) (Fig. 42).

7. Take the telescopic air duct from its pack.
Open the air duct out to the length:-

(30-40-50 PF) R + W + 91mm (39/16 in)
(60-70-80 PF) R + W + 147mm (53/4 in)

8. Using the tape provided seal the joints of the
three sections of the air duct, ensuring an overlap
of at least 30mm (1

3

/16in) at each joint (Fig. 43).

NOTE: The seams of all three sections must
be in line.

9. If the wall thickness (W) plus the distance from
the wall to the side of the boiler case (R) is less
than 202mm (8 in), it will be necessary to cut the
components of the air duct to make up the
appropriate size. Dispose of the centre section as
this is not required (Fig. 44).

(30-40-50 PF) R + W + 91mm (3

9

/16in)

(60-70-80 PF) R + W + 147mm (5

3

/4in)

10. Engage the sections, one inside the other,
then open the assembly out to wall thickness.
Tape the sections together using the tape
provided, ensuring that the seal is good (Fig. 45).

NOTE: The seams of both sections must be in
line.

30/40/50 = R + W + 168mm

60/70/80 = R + W + 224mm

W

R

30/40/50 = R + W + 91mm

60/70/80 = R + W + 147mm

Wall Thickness - 30mm

Wall Thickness - 30mm

Fig. 44

Fig. 45

Fig. 40

Fig. 41

Fig. 42

Fig. 43

5.0 Installation

21

5.10 Fitting the Flue and Back Plate

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

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

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

5.11 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. 47) and remove the side blanking cap by
pushing in and turning anti-clockwise to release
the bayonet fitting (Fig. 48).

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. 49).

4. Ensure all seams of the air duct sections are
uppermost and 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, ensuring
that the flue duct locates into position in the
terminal end of the air duct. 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. 50).

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

Fig. 46

Fig. 47

Fig. 48

Fig. 49

Fig. 50

Turret

Air Box
Blanking Plate

Blanking
Cap

Flue Duct

Air Duct

5.0 Installation

22

5.11 Method A (Cont)

7. Engage the assembly into the hole previously
cut in the wall and slide into place.

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 (Fig. 51).

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. 52).

10. The flue trim provided may be fitted, if
required, to neaten up the make-up around the
terminal. This plate may also be used as a
protection plate on outside walls of combustible
material.

11. Fit the trim over the flue terminal and mark
through the four securing holes. Remove the trim,
drill holes 63mm (2

1

/2in) deep to accept suitable
wall plugs. Fit the trim over the flue terminal and
secure using suitable screws (Fig. 53).

Fig. 52

Fig. 53

Fig. 51

5.0 Installation

23

5.12 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. 55) and remove the side blanking cap by
pushing in and turning anti-clockwise to release
the bayonet fitting (Fig. 55a).

3. Fit the support clamp provided, 60mm (2

1

/2in)
from the plain end of the flue tube and tighten with
the two screws (Fig. 56).

4. Fit the air duct over the flue duct ensuring that
the flue duct locates into position in the terminal
end of the air duct.

5. Ensuring all seams of the air duct are
uppermost, engage the air duct into the hole
previously cut in the wall and through holes in
other partitions (cupboards, walls, etc). Ensure
that the bayonet ends of the air duct and flue are
clear of the previously marked back plate area or
that they overhang it by no more than 50mm (2in).
Ensure that the ‘O’ ring seal is in position against
the sealing flange of the air duct (Fig. 57).

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 (Fig. 57).

7. Draw the flue duct towards the back plate air
box and 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.

8. Draw the air duct towards the air box on the
back plate, ensuring that the flue duct is located
into position in the terminal end of the air duct.
Engage the bayonet slots of the air duct over the
location lugs of the air box opening and press and
turn clockwise to secure the air box to the air
duct.

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

10. 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).

11. The flue trim provided may be fitted if
required, to neaten up the make-up around the
terminal. This plate may also be used as a
protection plate on outside walls of combustible
material.

Fit the trim over the flue terminal and mark
through the four securing holes. Remove the trim,
drill holes 63mm (2

1

/2in) deep to accept suitable
wall plugs. Fit the trim over the flue terminal and
secure using suitable screws (Fig. 59).

Support Clamps

60mm (21/2in)

Fig. 54

Fig. 55

Fig. 55a

Turret

Air Box
Blanking Plate

Blanking
Cap

Fig. 56

Fig. 57

Fig. 58

Fig. 59

Air Duct

Flue Duct

5.0 Installation

24

5.13 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. The guard manufacturers listed below can be
contacted for terminal sizes and guard model
numbers.

Tower Flue Components Ltd.,
Tower House,
Vale Rise,
Tonbridge,
Kent.
Tel: [phone].

Quinnell, Barrett & Quinnell,
884 Old Kent Road,
London, SE15 1NL.
Tel: [phone].

5.14 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

5.0 Installation

25

5.15 Internal Fitting Kit

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

o

. 226441) is suitable for walls between 100mm

(4in) and 280mm (11in) in thickness.

2. TO INSTALL THE KIT - Mark the flue hole
centre as described in section 5.4 or 5.8. 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

5.0 Installation

26

5.15 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

5.0 Installation

27

5.16 Fitting the Combustion Box

1. Offer up the combustion box to the back plate
and locate the rear bottom edge of the
combustion box onto the self locating support at
the base of the wall plate (Fig. 69).

2. Swing the top of the combustion box
backwards against the top air box (Fig. 70).

3. Engage the two retaining latches and secure
with the 'R' clips previously removed (Fig. 71).

Fig. 70

Fig. 69

Fig. 71

5.0 Installation

28

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

b

gy

bk

w

y

y

or/bk

y/r

y/bk

r/b

or
or

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

gy

w

y

bk

y

or

or

or/bk

or/bk

r/b

y/bk

y/r
w

PCB

Schematic

Wiring

Diagram

Pressure
Switch

Overheat
Thermostat

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

5.17 Electrical Connections

5.0 Installation

29

5.18 Making the Electrical Connections

1. Remove the cover from the control box by
removing the 2 screws (Fig. 72).

2. Slide the box forward for easier access.

3. The terminal strips may be removed by
carefully pulling them forward. Connect the supply
cable and the pump cable to the terminal strips
(Fig. 74).

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

4. The pump must be connected to the boiler
terminals.

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

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

7. Clamp the cables in the grips provided. Ensure
that the lengths of the supply cables are such that
the current carrying wires become taut before the
earth wires if the cable should pull out of the cable
clamp (Fig. 73).

8. Tuck the cables under 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.

9. A cable clip is provided in the base of the box.

Switched Live

Permanent Live

Neutral

Earth

Pump Earth

Pump Neutral

Pump Live

Fig. 72

Fig. 73

Fig. 74

5.0 Installation

30

5.19 Water Connections

1. The boiler has two side water connections, the
top connection being FLOW and the bottom
connection being RETURN (Fig. 75).

2. It is essential that FLOW and RETURN pipes
are connected to the correct fittings.

3. The top flow connection incorporates the boiler
thermostat, overheat thermostat and a venting
point (Fig. 76).

4. A copper elbow, compression nut and olive are
provided in the kit for the return connection.

NOTE: Drain cocks should be fitted to all the
system's low points.

5. Connect the two electrical tags of the thermostat
lead to the connections on the thermostat - either
wire can be connected onto either connection ­there is no polarity (Fig. 76).

6. Remove the overheat thermostat and clip from
the plastic kit bag. Engage the thermostat in the
clip as shown (Fig 76). Prise the clip over the flow
pipe as near to the vent as possible (Fig. 76 & 77).

7. Connect the two electrical tags from the wiring
harness to the terminals on the overheat
thermostat (Fig.77) - either wire can be connected
onto either terminal - there is no polarity.

5.20 Pipe Routes

1. Ensure that any pipework is routed so as to
leave the boiler via the spaces at the rear of the
outer case, either at the top or at the bottom.

2. Pipes may be dropped down within the outer
case in the spaces between the back plate and the
combustion box.

NOTE: It is important that the pipework does
not interfere with the correct fitting of the outer
case and a space of 14mm clearance must be
left between any vertical pipes and the outer
edge of the back plate.

5.21 Gas Connection

1. Connection to the gas supply is RC1/2(1/2in
BSPT internal) located at the rear of the gas cock
(Fig. 78).

2. When connecting the gas feed pipe, the control
box may be pulled forward to give greater access.

Fig. 75

Fig. 78

Venting Point

Plastic
Shroud
in place

Fig. 76

Boiler Thermostat

Overheat
Thermostat

Thermostat Clip

Flow Pipe

Orange Leads

Fig. 77

6.0 Commissioning the Appliance

31

6.1 Commissioning the Appliance

1. Flush the whole system in accordance with BS
5793:1992 (see Section 3.1 Water Circulating
Systems). Check for water leaks.

2. Purge away air from the supply pipe at the gas
service cock. (BS 6891: 1988) (Fig. 79).

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 anti-clockwise to the
ON position and check for gas soundness up to
the gas valve.

6. Loosen the pressure test point screw on the
right hand side of the gas control valve (there is
no need to completely remove this screw to
obtain a pressure reading) and connect a
pressure gauge.

7. Turn the boiler thermostat control knob fully
anti-clockwise to the OFF position marked 0
(Fig. 80).

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 5 seconds, the ignition spark will
commence. (NOTE: This may increase up to 1
minute in extremely cold weather).

11. The sparking will continue until the pilot light
is established (Fig. 81) 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.

0

6

5

4

3

2

1

*

Overheat

Boiler On

Fan On

Pilot On

Burner On

Overheat Neon
Warning

17 3

Fig. 79

Fig. 80

Fig. 81

6.0 Commissioning the Appliance

32

6.1 Commissioning the Appliance (Cont)

1. From the table opposite check that the main
burner pressure is correct after the appliance has
been running for 10 minutes.

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

3. If necessary, adjustment to main burner
pressure can be made by altering the regulator as
shown (Fig. 82).

4. To alter the burner pressure, turn the adjustment
screw in either direction until the required pressure
is obtained.

5. Turn the boiler thermostat to the OFF position
marked 0. Screw home the pressure test point
screw. Turn the boiler thermostat knob to the
required setting.

6. The boiler and system should be run and then
flushed and treated in accordance with
BS 5793:1992 and the flushing agent / inhibitor
manufacturers instructions. 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.

Model

Input Setting Pressure

kW Btu/h mbar in wg

30

Maximum 10.99 37, 500 16.0 +0.5 6.4 +0.2
Minimum

7.33 25, 000 8.0

+

0.5 3.2 +0.2

40

Maximum 14.65 50, 000 16.0 +0.5 6.4 +0.2
Minimum

11.36 38, 750 10.0

+

0.5 4.0 +0.2

50

Maximum 18.32 62, 500 16.0 +0.5 6.4 +0.2
Minimum 15.02 51, 250 11.5 +0.5 4.4 +0.2

60

Maximum 21.98 75, 000 16.0 +0.5 6.4 +0.2
Minimum 18.68 63, 750 11.5 +0.5 4.4 +0.2

70

Maximum 25.64 87, 500 16.0 +0.5 6.4 +0.2
Minimum 22.35 76, 250 12.16 +0.5 4.8 +0.2

80

Maximum 29.31 100, 000 16.0 +0.5 6.4 +0.2
Minimum 22.35 76, 250 9.5 +0.5 3.8 +0.2

Burner Pressure
Test Point

Regulator

Fig. 82

7.0 Fitting the Outercase

33

7.1 Fitting the Outercase

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

2. Taking the ready assembled outercase, the
front door of which has already been removed,
proceed as follows:

3. If the appliance is flued to the left or to the
right, remove the relevant infill panel by
removing the retaining clips and fixing screws
(Fig. 83).

4. Offer the outer case up to the hooks on the
top of the back plate (Fig. 85).

5. Ensure that the outer case is located over the
lower tabs on the back plate on both sides
(Fig. 86).

6. Using the two screws previously removed,
secure the outer case to the combustion box
(Fig. 84).

7. Replace the lower front door panel.

8. Instruct the user in the operation of the boiler
controls. Hand over both the Users Operating
and Installation Instructions giving advice on the
necessity of regular servicing.

Fig. 83

Fig. 84

Fig. 85

Fig. 86

Infill Panel

8.0 Overheat Cut-off Device

34

8.1 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 cut out.

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

2. Remove the lower door panel by following the
sequence of diagrams (Fig 87).

3. To reset the boiler - Turn the boiler
thermostat control knob fully anti-clockwise to the
OFF position marked ‘0’ (Fig. 88). Wait ten
seconds, turn the control knob clockwise to the
required thermostat setting, the red neon goes
out, the boiler will start automatically.

4. No adjustment to the gas controls or main
thermostat are required.

5. If the overheat thermostat drops out
repeatedly, refer to the fault finding chart at the
rear of this booklet or consult a competent
service engineer.

0

6

5

4

3
2

1

*

Overheat

Boiler On

Fan On

Pilot On

Burner On

Overheat Neon
Warning

1

2

3

Fig. 87

Fig. 88

9.0 Annual Servicing

35

9.1 Dismantling the Boiler

1. To ensure its continued safe and efficient
operation, it is important that the appliance is
regularly serviced. ( 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. Isolate the electrical supply to the boiler.

4. Remove the outer case lower door panel by
following the sequence of diagrams (Fig. 89).

5. Remove the outer case from the boiler by
unscrewing the two screws and lift the case clear
(Fig. 90).

6. Release the four latches holding the
combustion box door (Fig. 91). Remove the
combustion box door by pulling forward from the
bottom and unhooking its top edge (Fig. 93).

7. Release the 5-pin electrical plug connecting the
pressure switch and fan (Fig. 92). Withdraw the
fan assembly by pulling forwards from the top
edge (Fig. 93).

1

2

3

Fig. 89

Fig. 90

Fig. 91

Fig. 92

Fig. 93

9.0 Annual Servicing

36

9.2 Cleaning the Combustion Box

1. Remove the burner assembly by pulling it
forward (Fig. 94).

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

3. Lift the baffles out of the heat exchanger, using
the corner tabs on 30,40,50,60,70 models
(Fig. 94).

9.3

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.

9.4

Cleaning the Burner Injector

1. Remove the injector which is screwed into the
burner feed manifold (Fig. 95).

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

9.5 Cleaning the Pilot

1. Disconnect the spark electrode lead at the
electrode (Fig. 96).

2. Unscrew the electrode from the manifold and
withdraw the electrode (Fig. 96).

3. Remove the right hand side insulation carrier
bracket by releasing the screw. Remove the side
insulation (Fig. 94).

4. Release the screw securing the pilot hood and
remove (Fig. 96a).

5. Carefully remove the pilot injector (Fig. 96a).
Examine and clean it as necessary. Do not use a
wire or pin to clean the injector orifice.

6. Examine the sealing washer (Fig. 96a) and
replace if it is damaged in any way. Reassemble
in reverse order.

7. Replace all components in reverse order, (On
30,40,50,60,70 models refit the rear baffle by
holding it at an angle and locating the lower
fingers between the heat exchanger and rear
insulation. Lower it into position as shown)
(Fig. 97).

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.

60, 70 & 80 PF
Models Only

Fig. 94

Fig. 95

Fig. 97

Fig. 96

Fig.96a

Pilot Hood

Pilot Injector

Sealing Washer

Electrode

Baffles ­80 models only

Baffle ­30, 40, 50, 60, 70 models

Baffles - 30, 40, 50, 60, 70 models

10.0Changing Components

37

1

2

3

Centre
Pin

Retaining
Rivet

Fig. 98

Fig. 99

Fig. 100

Fig. 101

Fig. 102

Fig. 103

10.1 Changing Components

1. When changing components ensure that the
gas and electrical supplies are isolated before the
work is started.

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

3. Remove the outer case lower door panel
(Fig. 98).

4. Remove the outer case from the boiler by
unscrewing the two screws and lift the case clear
(Fig 99).

10.2 Replacing the Circuit Board

1. Ensure that the electrical supply is isolated.

2. Remove the cover from the front of the controls
box (Fig. 100).

3. Release the mains cables from the cable
clamps and unplug the mains connection blocks
from the circuit board (Fig. 101).

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

5. Carefully withdraw the centre pin from the
retaining rivet which then allows the retaining rivet
to be removed. Remove the thermostat control
panel (Fig. 102). (On reassembling ensure the
control panel is located over the retaining rivet
body before inserting the centre pin.)

6. Disconnect the plugs from the sockets on the
circuit board (Fig. 103).

7. Replace new circuit board in reverse order
checking that the connections are correct as
shown in the diagram (See Electrical Connections
section 5.17 of these instructions) and that the
harness is retained in the strain reliefs.

10.0Changing Components

38

10.3 Ignition Electrode (Fig. 104)

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.

10.4 Gas Valve (Fig. 105)

1. Disconnect the inlet gas cock union.

2. Remove the cover from the front face of the gas
valve and remove the electrical connections from
the tags on the gas valve.

3. Disconnect the gas valve by unscrewing the
three screws on the top face of the gas manifold. If
access to these screws is dificult the valve can be
removed with the manifold.

4. Remove the gas valve being careful not to
damage the gasket.

5. Fit the new gas valve by re-assembling all
components in reverse order, ensuring that the
gasket is properly positioned.

10.5 Thermostat Sensor (Fig. 106)

1. Disconnect the two electrical tags from the
sensor.

2. Unscrew the sensor from the top flow water
connection.

3. Screw in the new sensor with the plastic shroud
in place as a cover guard. Make sure that the
sensor is fully tightened into the top flow water
connection and connect the two electrical tags

- either wire can be connected onto either

connection - there is no polarity.

10.6 Over-Heat Thermostat

(Figs.106 & 107)

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

2. Remove the clip and thermostat from the pipe,
noting its position. Remove the retaining ‘O’ ring if
one is fitted and discard, disengage the thermostat
from the clip. If the clip is a metal one, discard and
use the plastic clip supplied in the kit.

3. Engage the new thermostat in the clip. Prise the
clip over the flow pipe ensuring it is positioned as
previously. 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. 104

Fig. 105

Electrode

Plastic
Shroud
in place

Fig. 106

Overheat
Thermostat

Thermostat Clip

Flow Pipe

Orange Leads

Fig. 107

10.0Changing Components

39

10.7 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 (Fig. 108). Remove the combustion box
door by pulling forward from the bottom and
unhooking its top edge (Fig. 110).

3. Release the 5-pin electrical plug connecting the
pressure switch and fan (Fig. 109). Withdraw the
fan assembly by pulling forwards from the top
edge (Fig. 110).

10.8 Fan (Fig. 111)

IMPORTANT - 80 PF Models Only. On

appliances up to serial n

o

8999 use replacement

fan Baxi Part N

o

229422 G.C.No364 979.

From serial n

o

9000 use replacement fan Baxi

Part N

o

237578 G.C.No 170 615.

1. Disconnect sensing probe from the pressure
switch at rubber tube connector.

2. Disconnect the 2 fan wires from the connection
on the electrical plug. Unscrew bracket securing
sensing probe into top of fan and remove the
sensing probe. 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, reconnect the new
fan wires into the connections on the electrical
plug - either wire can be connected into either
connection.

10.9 Pressure Switch (Fig. 112)

1. Disconnect sensing tube.

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 in reverse order of dismantling
ensuring that the electrical terminals are
connected to their correspondingly marked tags.

Grey

Black

White

Fig. 108

Fig. 109

Fig. 110

Fig. 111

Fig. 112

Outlet Flange

Sensing Tube

Sensing Tube

Fan

10.0Changing Components

40

10.10 Burner (Fig. 113)

1. Remove the burner assembly by pulling it
forward.

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

10.11 Burner Injector (Fig. 114)

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.

10.12 Pilot Burner Injector (Fig. 115)

1. Remove the right hand side insulation carrier
bracket by releasing the screw. Remove the side
insulation panel.

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.

10.13 Gas Manifold (Fig. 116)

1. Remove the right hand side insulation carrier
bracket by releasing the screw. Remove the side
insulation panel (Fig. 113).

2. 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.

3. Remove valve and ancillary components from
manifolds as necessary.

4. 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.

60, 70 & 80 PF
Models Only

Fig. 113

Fig. 114

Fig. 115

Fig. 116

Pilot Hood

Pilot Injector

Sealing Washer

1.0 Introduction

41

11.0Short parts list

44

40

71

75

25

24

26

61

73

66

48

66a

77

53

30

39

2

3

4

5

6

7

71a

11.1 Short Parts List

26

Key Description Model G.C. Manuf'rs
N

o

N

o

Part N

o

39 Burner 30-40-50 364 878 231708

60-70-80 364 879 231709

44 Burner Injector 30 364 880 231354

40 364 881 231355
50 364 882 228104
60 364 873 231776
70 E01 623 239619

80 364 981 231777

40 Ignition Pilot Kit All models 170 558 236142
75 Electrode Lead All models 364 745 225826
71 Control Knob All models 364 886 230981
30 Viewing Window Kit All models 364 588 224183
53 Pressure Switch All models 379 033 230068
25 Insulation R.H. All models 364 889 230653
24 Insulation L.H. All models 364 890 230652
26 Retaining Brackets All models 364 891 230817
61 Control Valve All models 379 202 231857
77 Overheat Thermostat All models E03 921 241792
66a Fuse All models 364 892 231402
48 Fan 30-40-50-60 229421

80 up to serial n

o

8999

364 979 229422

after serial n

o

9000

170 615 237578

70 from serial n

o

00001

170 615 237578

73 Thermostat Sensor All models 379 030 230204
66 Control Board All models 379 031 231711
2 Panel Top 30-40-50 364 893 230442

60-70-80 364 894 230863

3 Panel Upper 30-40-50 364 895 230443

60-70-80 170 602 229428

4 Panel Lower 30-40-50 364 897 231406

60-70-80 364 898 231429

5 Panel Bottom 30-40-50 364 899 230446

60-70-80 364 900 230868

6 Panel L.H. All models 364 901 230439
7 Panel R.H. All models 364 902 230951
71a Potentiometer & Leads All models 379 960 237140

12.0Fault Finding

42

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 20

o

C)

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.

12.0Fault Finding

43

Replace the gas

valve

Replace PCB

Boiler satisfactory

Set pressure

regulator

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 in the flue terminal.

Failure to comply with the recommended fitting
instructions will adversly 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)

Baxi Heating Limited

Brownedge Road

Bamber Bridge Preston

Lancashire

PR5 6SN

www.baxiheating.co.uk

The Baxi Helplines

For General Enquiries
+44 (0)1772
695555

For After Sales Service
+44 (0)1772
695505

For Technical Enquiries
+44 (0)1772
695504

Comp No230988 - Issue 22 - 11/98