157290-3.pmd

Concord CXA/H

- Installation and Servicing

GENERAL

CAUTION.

To avoid the possibility of injury during the installation, servicing or cleaning of

this appliance care should be taken when handling edges of sheet steel components.

Boiler

CXA 40/H CXA 50/H CXA 60/H CXA 70/H CXA 80/H CXA 90/H CXA 100/H CXA110/H CXA120/H

Number of sections

Flow tappings

Rc (in. BSP)

2 x 2 at rear

Return tappings

Rc (in. BSP)

2 x 2 at rear

Maximum static head metres (feet)

61 (200)

Maximum pressure

bar (p.s.i.)

6.0 (87)

Gas inlet connection Rc (in. BSP)

3/4 (3/4)

1 (1 )

Minimum dynamic

mbar gauge

15.0

16.5

15.0

16.5

15.5

16.5

17.0

17.5

gas pressure required
at the boiler inlet

(in.w.g.)

(6.0)

(6.6)

(6.0)

(6.6)

(6.2)

(6.6)

(6.8)

(7.0)

Electricity supply

230 Volts- single phase, 50 Hz, fuse 5 A

Nominal flue size (to BS. 835) m m

150

175

200

250

(in.)

(6)

(7)

(8)

(10)

Diverter outlet socket

m m

184

213

238

288

internal diameter

(in.)

(7.3)

(8.4)

(9.4)

(11.3)

Length of burner bars (overall) m m

377

497

617

737

857

(in)

(14.8)

(19.5)

(24.3)

(29.0)

(33.7)

Main burner injectors( 3 off) size, mm

3.4

3.82

4.12

4.57

4.86

5.2

5.3

5.5

Approximate dry weight

210

265

330

395

490

(lb.)

(463)

(584)

(727)

(871)

(1078)

Water content

litre

(gal.)

(4.8)

(6.6)

(8.2)

(9.9)

(11.7)

Table 2 - General Data

* This value is in the UK government's Standard Assessment Procedure (SAP) for energy rating of dwellings.
The test data from which it has been calculated has been certified by Advantica 0087.

Boiler

CXA 40/H CXA 50/H CXA 60/H CXA 70/H CXA 80/H CXA 90/H CXA 100/H CXA 110/H CXA 120/H

Number of Sections

Boiler Input

Gross

48.3

60.3

72.4

84.5

96.5

108.6

120.7

132.7

144.8

Btu/hr x 1000 164.7

205.8

247.0

288.2

329.3

370.5

411.7

452.8

494.0

Nett

43.5

54.3

65.2

76.1

87.0

97.8

108.7

119.6

130.4

Btu/hr x 1000 148.3

185.4

222.5

259.6

296.7

333.8

370.9

408.0

445.0

Boiler Output

100

110

120

Btu/hr x 1000 136.5

170.6

204.7

238.8

273.0

307.1

341.2

375.3

409.4

Gas rate

4.60

5.75

6.90

8.05

9.20

10.35

11.50

12.64

13.79

/h 162.4

203.0

243.6

284.2

324.8

365.4

406.0

446.6

487.1

Approx. flue

4.5% CO

&100°C.m

0.04

0.05

0.06

0.07

0.08

0.09

0.10

0.11

0.12

gas volume

4.5% CO

& 212°F. ft.

106

127

148

170

191

212

233

254

Manifold setting pressure

mbar

9.7

9.8

10.2

10.0

9.3

9.6

10.7

11.1

12.1

in.w.g.

3.9

4.1

4.0

3.7

3.8

4.3

4.4

4.8

Part load efficiency (Gross)

83.5

83.6

83.4

82.4

82.6

83.8

81.9

83.7

85.1

Seasonal efficiency (SEDBUK)*

[79.9]% [79.9]% [79.9]% [79.9]% [79.9]% [79.9]% [79.9]% [79.9]% [79.9]%

Table 1- Performance Data

Note. To obtain gas consumption in l/s, divide gross heat input in (kW) by a calorific value of 37.8 (MJ/m

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Concord CXA/H -

Installation and Servicing

CONTENTS

Air Supply. ........................................................................ 8

Boiler Assembly - exploded view. ................................... 9

Boiler Clearances. ........................................................... 5

Burner Assemblies - exploded views.

CXA 40/H-80/H ........................................................... 22
CXA 90/H-120/H ......................................................... 22

Casing Assembly. ........................................................... 19

Chimney System. .............................................................. 8

Commissioning & Testing. ............................................. 17

Electrical Connections. .................................................. 13

Electrical Supply. .............................................................. 8

Fault Finding. ................................................................... 28

Gas Safety Regulations .................................................... 3

Gas Supply. ........................................................................ 8

Hydraulic Resistance. ...................................................... 5

Initial Lighting. ................................................................. 17

Installation. ........................................................................ 9

Mandatory Requirements. ............................................... 7

Option Kits. ........................................................................ 4

Pump. ................................................................................ 6

Servicing. ........................................................................ 19

Short List of Parts. ......................................................... 30

Site Assembled Boilers. ................................................. 26

Static Head Requirements. .............................................. 6

System Connections. ..................................................... 11

Ventilation. ........................................................................ 8

Water Circulation. ............................................................ 4

Water Connections. ......................................................... 4

Water Treatment. ............................................................. 6

Wiring Diagrams. ............................................................ 14

Concord CXA 40/H-120/H (Natural gas)

B.G. Certified - P.I. No. 87/AP/80

Destination Countries: GB and IE

INTRODUCTION
CONSTRUCTION

BOILER BODY

The sectional boiler body is of cast iron and is supplied
assembled on a sheet steel combustion chamber with an integral
draught diverter. The boiler can be supplied in sectioned form to
special order for site assembly - refer to the section headed
`Instructions for Site Assembled Boilers'.

CASING

The casing is manufactured in stove enamelled sheet steel
and is easily assembled on site.

BURNERS

The 3 burners are of stainless steel construction.

Gas Safety (Installation and Use) Regulations or rules
in force.

It is the law that all gas appliances are installed and serviced by
a CORGI registered installer in accordance with the above
regulations. Failure to install appliances correctly could lead to
prosecution. It is in your own interest, and that of safety, to ensure
that the law is complied with.

The Concord CXA 40/H-120/H range of boilers has been tested
and certified by British Gas to prEN656 for use with Natural gas
only.

Multiple boiler installations

The Concord CXA/H range is certificated for use in multiple
boiler installations, providing that the following conditions are
satisfied.

1. A downdraught thermostat kit MUST be fitted to ALL boilers

in the installation.

2. A maximum of 6 boilers may be used with a single flue

header.

3. For clearances see Frame 2.

A comprehensive guide to multiple installations of Concord
CXA/H boilers is available.
WARNING.
Failure to use a downdraught kit on every boiler in a multiple
boiler installation will negate the certification of the installation
and therefore contravene the essential requirements of the Gas
Appliance Directive.

Note. Concord CXA 40/H, CXA 50/H and CXA 60/H boilers are
intended for use as COMMERCIAL BOILERS and are NOT
certified for use in domestic applications. A domestic installation
is defined as an installation where the boiler takes its combustion
air from a living space or from a room directly or indirectly
connected with the living space. It is important, therefore, that no
external control devices - e.g. flue dampers, economisers etc.,
are directly connected to this appliance unless covered by these
Installation and Servicing Instructions or otherwise recommended
by Caradon Ideal Limited in writing. If in doubt, please enquire.

Any direct connection of a control device not approved by Caradon
Ideal Limited could invalidate the British Gas Certification, the
normal appliance warranty and could also infringe the Gas Safety
Regulations. Table 1, Table 2 and the descriptive notes which
follow contain all the essential data likely to be required by the
installer.

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Concord CXA/H

- Installation and Servicing

GENERAL

Boiler Size

Cold Feed

Open Vent

CXA 40/H - 50/H

3/4

CXA 60/H -120/H

1/4

Sealed system filling point - refer to Frame 8

Flow and return connections are 2" BSP.
A 1" BSP tapping is provided in the redundant return flange for
the cold feed or expansion vessel connection.
Safety Valve
A safety valve must be sized and fitted in accordance with BS.
6644 for every type of system. The valve should be set at 0.7
bar (10 lb/in.

) above the operating pressure in the boiler. The

maximum safety valve setting is 0.7 bar (10 lb/in.

) above the

maximum design operating pressure of 6 bar (87 lb/in.

Cold Feed/Open Vent
The independent cold feed and the open vent must comply
with BS. 6644 and be of the following minimum size.

WATER CONNECTIONS

GAS CONTROLS

Control is by automatic ignition of intermittent pilot; once the
presence of a flame has been proved the single (or double) main
gas valves open to give full heat input. The mains voltage supply
is via a terminal plug connection at the control box.

ELECTRICAL CONTROLS

The boiler is supplied with 2 printed circuit boards; Board
S4561B1054 is the ignition board containing the flame proving
logic and the on-board spark generator. Board W4115A1020
contains the electronic thermostat and the pump overrun timer. A
preset overheat thermostat is also fitted. The control box displays
neons indicating boiler status as follows:

Boiler on

Lockout

Overheat

A 4 minute anticycle delay is built in to the controls to prevent rapid
cycling.

FROST PROTECTION

Frost protection is incorporated in the boiler as long as there is a
permanent live supply wired to terminal L1 on the terminal plug-in
connection at the control box and the boiler thermostat knob is not
switched to off.

If the temperature sensed by the boiler thermostat falls to about
5

C the boiler will fire until the temperature reaches 18

C. Note

that this is designed to protect the boiler and may not necessarily
protect the remote parts of the system.

OPTION KITS

Remote indication kit
This kit gives the facility of remote indication of the boiler status.

Pressure gauge kit
In addition to the above control kit, an optional pressure gauge
is also available for the range of boilers. Details for fitting are
included with the pressure gauge.

Downdraught thermostat kit
This kit is optional when used on a single CXA/H installation, but
mandatory when used on a multiple boiler installation.

DUTY

The range of boilers is suitable for: Combined indirect pumped
domestic hot water and central heating systems; Independent
indirect pumped domestic hot water or central heating systems.

Fully pumped systems may be open vented or sealed.

The range of boilers is NOT suitable for:

1. Gravity DHW systems.
2. Gravity heating systems.
3. Direct domestic hot water supply.

WATER CIRCULATION SYSTEM

Due to the compact nature of the boiler the heat stored within the
castings at the point of shutdown of the burner must be dissipated
into the water circuit in order to avoid the overheat thermostat tripping.
In order to allow pump operation after burner shutdown the boiler
control box incorporates a pump overrun facility which operates for
approximately 6 minutes after burner shutdown and, in order to
make use of this, the pump must be wired to the appropriate
terminal L2 (pump) in the boiler control box.

1. The minimum flow rate as given in Table 4 must be

maintained whenever the boiler is firing and during the pump
overrun period.

2. During the period of pump overrun there must be an open

circuit of adequate water volume and/or load. The minimum
size of this circuit is given by the use of Graph 1.

Examples shown on Graph 1

a. For the CXA 90/H and CXA 100/H the minimum circuit during

pump overrun could be a load of 6 kW with a volume of 31
litres or any other combination given by the relevant line.

b. For the CXA 70/H and CXA 80/H the minimum circuit during

pump overrun could be a load of 2 kW with a volume of 45
litres or any other combination given by the relevant line.

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Concord CXA/H -

Installation and Servicing

GENERAL

POSITION OF BOILER

Minimum clearances required
from walls or other fixed objects
to allow for the free access of
combustion air are shown in
Table 3 above.

However, for maintenance
purposes we suggest a
minimum rear clearance of
50mm.

Any combustible material
adjacent to the boiler and its
flue system must be so placed
or shielded as to ensure that
its temperature does not
exceed 65

C (150

F).

MULTIPLE BOILER INSTALLATIONS

The minimum installation clearances must conform to the
dimensions given below:

CXA 40/H, 50/H, 60/H, 70/H & 80/H

Clearance between boilers = 50mm
Clearance at both ends of the multiple installation = 50mm*

CLEARANCES & DIMENSIONS

Table 3

CXA 90/H, 100/H, 110/H & 120/H

Clearance between boilers = 100mm
Clearance at both ends of the multiple installation = 100mm*

Rear clearance: sufficient clearance should be given at the rear
of the boiler for connection of gas and water pipework.
*Additional clearance is required for access at either end of the
installation.

100

CON5220

Example A

Example B

CXA

100/H & CXA

90/H

CXA

80/H & CXA

70/H

CXA

40/H

CXA

60/H & CXA

50/H

Heat Load During Pump Overrun (kW)

Water Volume in Circuit during Pump Overrun (litres)

Relationship between load and water volume for the

minimum capacity of water circuit during the 6 minute

pump overrun period for different boiler outputs.

Graph 1 - Heat Load / Water Volume

CXA

110/H & CXA

120/H

10 20 30 40 50 60 70 80 90 100 110 120 130 140 150

190 200

160 170 180

120

110

100

Graph 2 - Hydraulic Resistance

Hydraulic Resistance (mbar)

Flow (litres/min)

C(20

F) - CXA

40/H

C(20

F) - CXA

50/H

C(20

F) - CXA

60/H

C(20

F) - CXA

70/H

C(20

F) - CXA

80/H

C(20

F) - CXA

90/H

C(20

F) - CXA

100/H

C(20

F) - CXA

10/H

C(20

F) - CXA

120/H

CON5221

Boiler Size

CXA 40/H

CXA 50/H

CXA 60/H CXA 70/H CXA 80/H

CXA 90/H CXA100/H CXA110/H CXA120/H

No. of sections

Front clearance mm (in)

750 (29

1/2

)

Rear clearance mm (in)

150 (6)

300 (12) 300 (12) 300 (12) 300 (12)

Side clearance mm (in)

50 (2)

100 (4)

Dimension A

m m

750

882

1042

1212

1385

1/2

3/4

1/2

Dimension B

m m

108

122

135

190

160

1/4

7/8

3/8

1/2

1/4

Dimension C

m m

931

893

5/8

7/8

3/8

3\16

3/16

Dimension D

m m

177

187

224

271

321

3/8

7/8

5/8

Dimension E

m m

116

163

213

3/4

1/8

5/8

1/2

3/8

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Concord CXA/H

- Installation and Servicing

GENERAL

Particular reference should be made to BS. 6644: Section 2;
Subsection 10 and Guidance note PM5 "Automatically
controlled steam and hot water boilers" published by the
Health and Safety Executive.

The information and guidance given below is not intended
to override any requirements of either of the above
publications or the requirements of the local authority, gas or
water undertakings.

Other British Standards applicable are BS.5422 and
BS.6700.

The information provided is based on the following
assumptions:

1. An independent open vent/safety pipe connection is

made to the redundant boiler flow tapping or is
positioned immediately after the system flow pipe
connection to the header, as shown.

2. An independent cold feed/expansion pipe connection is

made to the redundant boiler return tapping. Cold feed/
expansion pipe connections made to the pumped
system return will result in an increase in the static head
requirement, caused by the additional resistance of the
distributor tube. Surging may also increase.

3. The maximum flow rate through the boiler is based on a

temperature difference of 11 °C at full boiler output and
the circulating pump is positioned in the flow to the
system.

4. The boiler is at the highest point of circulation in the

system. Systems designed to rise above the boiler flow

Note A. This minimum height must be
increased, if necessary, to comply with the
minimum head required by the pump
manufacturer in order to avoid cavitation.

Note B. This diagram does not show safety
valves, water flow switches, etc., necessary for
the safe operation of the system.

tappings will automatically require a minimum static head higher
than that shown.

5. The position of the open vent/safety pipe above the expansion

cistern water level is given as a guide only. The final position will
depend upon the particular characteristics of the system. Pumping
over of water into the expansion cistern must be avoided.

The above circuit capacity during pump overrun may be
achieved either by provision of an adequate bypass circuit
or by ensuring that a zone of suitable size is open for
circulation during this period by relevant control of zone
valves or pumps.

The wiring diagrams in Frames 17, 18 & 19 illustrate the
control methods for achieving the above.

3. Pump selection should take account of the hydraulic

resistance given in Graph 2.

PUMP POSITIONS

Whenever practically possible the circulating pump(s) should be
positioned so that it pressurises the system being served. The
vertical distance between the pump(s) and any cold feed and
expansion cistern MUST comply with the pump manufacturers
requirements in order to avoid cavitation. These requirements
override the information given in Frame 3 if the static head required
for the pump(s) exceeds that required for the boiler.

MINIMUM FLOW OF WATER - Refer to Table 4

The system design must provide for an adequate flow rate through
the boiler at all times when the boiler is firing. The minimum flow
rate should correspond to a temperature difference across the
boiler flow and return of 35

C (63

F), assessed at catalogue

rating.

3 OPEN VENTED SYSTEMS - Minimum static head requirements

WATER TREATMENT FOR HOT WATER AND
HEATING BOILERS

There is a basic need to treat the water contained in all heating
and indirect water systems, particularly open vented systems. It is
assumed, incorrectly, that because boilers are operating in
conjunction with what is apparently a closed circuit an open vented
system will not, under normal circumstances, allow damage or
loss of efficiency due to hardness salts and corrosion once the
initial charge of water has been heated up a few times.

1mm of lime reduces the heat transfer from metal to water by 10%.

Table 4 - Flow rates for fully pumped systems

Boiler

Minimum flow rates for a

temperature difference of 35

C (63

l/s

g.p.m.

CXA 40/H

0.28

3.7

CXA 50/H

0.34

4.5

CXA 60/H

0.41

5.4

CXA 70/H

0.48

6.3

CXA 80/H

0.55

7.3

CXA 90/H

0.62

8.2

CXA 100/H

0.68

CXA 110/H

0.75

9.9

CXA 120/H

0.82

10.9

CON5349

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Concord CXA/H -

Installation and Servicing

GENERAL

In practice the deposition of these salts is liable to cause noises
from the boiler body or even premature boiler failure. Corrosion
and the formation of black iron oxide sludge will ultimately result
in premature radiator failure.
Open vented systems are not completely sealed from the
atmosphere if proper venting and expansion of system water is
to be achieved. The same tank is used to fill the system with
water and it is through the cold feed pipe that system water
expands into the tank when the boiler passes heat into the
system. Conversely, when the system cools, water previously
expelled is drawn back from the tank into the system together
with a quantity of dissolved oxygen.
Even if leakage from the heating and hot water system is eliminated
there will be evaporation losses from the surface of the tank which,
depending upon ambient temperature, may be high enough to
evaporate a large portion of the system water capacity over a full
heating season.
There will always be corrosion within a heating or hot water system
to a greater or lesser degree, irrespective of water characteristics,
unless the initial fill water from the mains is treated. Even the
water in closed systems will promote corrosion unless treated.
For the reason stated, Caradon Ideal Limited strongly recommend
that, when necessary, the system is thoroughly cleaned, prior to
the use of stable inhibitor, which does not require continual topping
up to combat the effects of hardness salts and corrosion on the
heat exchangers of the boiler and associated systems.
Caradon Ideal Limited advise contact directly with specialists on
water treatment such as:
Fernox Manufacturing Co. Ltd., or
Tandem House,
Marlowe Way,
Croydon.
Surrey CRO 4XS
Tel 0870 601 5000

Pressure vessels used must comply with BS. 4814 and must
be sized on the basis of the total system volume and initial
charge pressure.

Initial minimum charge pressure should not be less than 0.5
bar (7.2 psi) and must take account of static head and
specification of the pressurising equipment. The maximum
water temperatures permissible at the point of minimum
pressure in the system are specified in Guidance Note PM5.

When make-up water is not provided automatically it will be
necessary to fit controls which shut down the plant in the event
of the maximum system pressure approaching to within 0.35
bar (5 psi) of safety valve setting.

Other British Standards applicable to commercial sealed
systems are:-

BS. 6880: Part 2.
BS. 1212
BS. 6281: Part 1
BS. 6282: Part 1
BS. 6283: Part 4

Working pressure 6 bar maximum.

Particular reference should be made to BS. 6644: Section 6
and Guidance note PM5 "Automatically controlled steam and
hot water boilers" published by the Health and Safety
Executive.

The information and guidance given below is not intended to
override any requirements of either of the above publications or
the requirements of the local authority, gas or water
undertakings.

In general commercial closed pressurised systems are
provided with either manual or automatic water make up.

On both instances it will be necessary to fit automatic controls
intended to protect the boiler, circulating system and ancillary
equipment by shutting down the boiler plant if a potentially
hazardous situation should arise.

Examples of such situations are low water level and operating
pressure or excessive pressure within the system. Depending
on circumstances, controls will need to be either manual or
automatic reset. In the event of shutdown both visual and
audible alarms may be necessary.

requirements of the Gas Safety Regulations, current I.E.E.
(BS.7671) Regulations, Model Water Bye-laws, local water authority
bye-laws and it should also comply with any relevant requirements
of the local gas region, local authority and the relevant British
Standard Codes of practice and building regulations.

FOR SMALL PIPE INSTALLATIONS
BS. 6891;

Installation of low pressure pipework

FOR LARGE PIPE INSTALLATIONS

Gas Installations
IGE-UP-1:

Purging Procedures of Non-domestic Gas
Installations. Soundness Testing Procedures
for Industrial and Commercial.

IGE-UP-2:

Guidance notes on the Installation of Gas
Pipework, Boosters and Compressors in
Customer's Premises Equal to or Greater than
25mm (Non-domestic).

IGE-UP-10:

Installation of Gas Appliances in Industrial and
Commercial Premises.

BS.6644:

Installation of Gas Fired Hot Water Boilers
70kW to 1.8MW (net).

BS 6880 Pt 1-3: Water Supply.
CP342:2:

Centralised Hot Water Supply.

Model Water Bye-laws
Manufacturers notes must not be taken, in any way, as overriding
statutory obligations.

FOUNDATION

The boiler must stand on a non-combustible floor (i.e. concrete
or brick) which must be flat, level and of a suitable load bearing
capacity to support the weight of the boiler (when filled with
water) and any ancillary equipment.
If the boiler is mounted on a plinth then the dimensions must
exceed the plan area of the boiler by at least 75mm on each
side.

SEALED (PRESSURISED) SYSTEMS

INSTALLATION REQUIREMENTS

The appliance must be installed by a CORGI registered installer.
The installation of the boiler must be in accordance with the relevant

Sentinel Division
Betz Dearborn Ltd.,
Widnes,
Cheshire, WA8 8UD
Tel. 0151 424 5351.

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Concord CXA/H

- Installation and Servicing

GENERAL

Position ventilation grilles to avoid the risk of accidental
obstruction by blockage or flooding. If further guidance on
ventilation is required then consult BS.6644 and BS.5440:2.:
2000

AIR SUPPLY BY MECHANICAL VENTILATION

The supply of air by mechanical means to a space housing the
boiler should be by mechanical inlet with natural or
mechanical extraction. Mechanical extract ventilation with
natural inlet must NOT be used.

Where a mechanical inlet and a mechanical extract system is
applied, the design ventilation flow rates should be as in Table
4 of BS.6644.

The requirements for air supply by mechanical ventilation are
given in BS.6644.

Note. For mechanical ventilation systems an automatic control
should be provided to cause safety shutdown or lockout of the
boiler(s) in the event of failure of air flow in either inlet or extract
fans.

IMPORTANT. The use of an extractor fan in the same room as
the boiler (or in an adjacent, communicating room) can, in
certain conditions, adversely affect the safe operation of the
boiler. Where such a fan is already fitted (or if it is intended to
fit an extractor fan after installation of the appliance) the advice
of the Gas Region should be obtained.

Tests for spillage of products from the draught diverter when
the extractor fan is running and all doors and windows are shut
should be carried out after installation. If spillage is detected,
the area of permanent ventilation must be increased.

CHIMNEY SYSTEM

To ensure the safe and satisfactory operation of the boiler the
chimney system (which may be common or individual, in the
case of twin or multiple boiler installations) must be capable of
the complete evacuation of combustion products at all times.
The effective height of the chimney terminal(s) above the boiler
outlet(s) must ensure sufficient buoyancy to overcome the
resistance of the bends, tees and runs of the flue pipe involved
and shall terminate in a down draught free zone. The number of
bends and lengths of horizontal flue pipe used should be kept to
a minimum in order to reduce gas flow resistance.

Compliance with the recommendations made in BS.6644,
IGE UP/10 Installation of Gas Appliances in Industrial and
Commercial Premises and the Third Edition of the 1956 Clean
Air Act Memorandum' should be strictly observed where
applicable.

The chimney design should avoid the formation of excessive
quantities of condensate. For this reason it is recommended
that all chimneys are insulated and lined. In the case of brick or
similar structures a stainless steel rigid or flexible flue liner
(grade 304/316) may be used in conjunction with a 50 mm
(minimum) thick layer of vemiculite or perlite granules between
the liner and the inner skin of the chimney body. Liners should
be sealed at both top and bottom.

As the Concord CXA/H range of boilers is supplied complete
with an integral draught diverter, a diverter MUST NOT be fitted
within the chimney system.

Drainage points positioned at the bottom of all vertical chimney
sections should be provided. Drain pipes should be no less
than 25 mm I.D., manufactured from acid condensate resistant
material such as stainless steel and be positioned so that pipe
runs and discharge points are not subject to the effects of frost
and that flue gases cannot leak into the boiler room.

Care should be taken to ensure the specification of the chimney
is suitable for the application by reference to the manufacturers
literature. Caradon Ideal Limited can offer advice on the design
of suitable chimney systems.

GAS SUPPLY

If there is any doubt regarding the capacity of the gas meter, the
available gas pressure, the adequacy of existing service pipes
or the size required for new service pipes then the advice of the
gas region should be requested.

Installation pipework should be fitted and tested for gas
soundness in accordance with BS. 6891;

IGE-UP-1 for small installations

IGE-UP-2 for large installations.

The local gas region must be consulted if it is necessary to
employ a gas pressure booster.

ELECTRICAL SUPPLY

WARNING. This appliance must be efficiently earthed.

A 230 V - 50 Hz mains supply is required, fused at 5 amps.

Wiring external to the appliance MUST be in accordance with the
I.E.E. (BS. 7671) Wiring Regulations and any local regulations
which apply.

For details of connections refer to Frame 14.

VENTILATION

Safe, efficient and trouble-free operation of open flued gas
boilers is vitally dependent on the provision of an adequate
supply of fresh air to the room in which the appliance is
installed. Ventilation by grilles communicating to the outside
air is required. The minimum free area and required
positioning of these grilles must be in accordance with Tables
5 & 6.

Table 5 (to BS5440)
CXA 40/H-60/H boilers installed in a room or internal space

Boiler size

Air vent free area cm

202

247

304

This air vent shall be direct to outside air or to a room or
internal space itself with an air vent to outside air of the same
size.

Table 6 (to BS6644)
CXA 70/H-120/H boilers
Required area (cm

) per kW of total rated input (net)

Boiler room

Enclosure

Low level (inlet)

High level (outlet)

Note: Where a boiler installation is to operate in summer
months (e.g. DHW) additional ventilation requirements
are stated, if operating for more than 50% of time (refer
to BS6644).

157290-3.pmd

11/7/2005, 11:09 AM