Glow-worm 24cxi, 30cxi, 38cxi Instructions For Use Installation And Servicing

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10081

Hepworth Heating Ltd., Nottingham Road, Belper, Derbyshire. DE56 1JT

To be left with the user

Instructions for Use

Installation and Servicing

24cxi 30cxi 38cxi

G.C. No. 47-047-23

G.C. No. 47-047-24

High Efficiency

Condensing

Combination Boilers

2000225065A.01.03

G.C. No. 47-047-27

2000225065A

For customer service call:

0044 (0)1773 828100

Technical helpline: 0044 (0)1773 828300

For General and Sales enquiries:

Tel. 0044 (0)1773 824141

Fax: 0044 (0)1773 820569

To register your Glow-worm appliance call:

0044 (0)208 247 9857

Guarantee Registration

Thank you for installing a new Glow-worm appliance in your home. Glow-worm appliances are manufactured to the very highest standard so we are pleased to offer our customers a Comprehensive Guarantee. This product is guaranteed for 24 months from the date of installation or 30 months from the date of manufacture, whichever is the shorter, for parts. In addition this product is guaranteed for 12 months from the date of installation or 18 months from the date of manufacture, whichever is the shorter, for labour. The second year of the parts guarantee, from the beginning of the 13th month onwards after installation or manufacture, is conditional upon the boiler having been serviced by a CORGI registered gas installer, in accordance with the manufacturer's recommendations. We strongly recommend regular servicing of your gas appliance, but where the condition is not met, any chargeable spare parts or components issued within the applicable guarantee period still benefit from a 12 month warranty from the date of issue by the manufacturer.

We recommend you complete and return as soon as possible your guarantee registration return literature, supplied in the document envelope.

If your guarantee registration return literature is missing you can obtain a copy or record your registration by telephoning the Heatcall Customer Service number 0044 (0)1773 828100.

3 2000225065A

SERVICING

INSTRUCTIONS

CONTENTS DESCRIPTION SECTION PAGE No.

INSTRUCTIONS

FOR USE

INSTALLATION

INSTRUCTIONS

Important Information 4 Draining and Filling 5 Appliance Introduction 5 Appliance Safety Devices 6 Maintenance and Servicing 6 Operating the Boiler 7

General Information 1 9 Boiler Location and Ventilation 2 12 Flue Location and Ventilation 3 13 Heating System 4 15 Domestic Hot Water System 5 17 Installation Preparation 6 18 Flue Preparation 7 20 Gas/Water Connections and Boiler Fixing 8 22 Safety Valve Discharge and Condensate Connections 9 23 Electrical Connections 10 24 Commissioning 11 26

Servicing 12 29 Fault Finding 13 33 Replacement of Parts 14 35 Spare Parts 15 46

Contents

The instructions consist of three parts, User, Installation and Servicing Instructions, which includes the Guarantee Registration Card. The instructions are an integral part of the appliance and must, to comply with the current issue of the Gas Safety (Installation and Use) Regulations, be handed to the user on completion of the installation.

2000225065A

Gas safety (Installation and use) Regulations

In your interests and that of gas safety, it is the law that ALL gas appliances are installed and serviced by a competent person in accordance with the above regulations.

Testing and Certification

This boiler is tested and certificated for safety and performance. It is therefore important that no alteration is made to the boiler, without permission, in writing, from Hepworth Heating Ltd.

Any alteration not approved by Hepworth Heating Ltd., could invalidate the certification, boiler warranty and may also infringe the current issue of the Statutory Requirements. The requirements are: The installation of this boiler must be carried out by a competent person in accordance with the current rules in force in the countries of destination at the time of installation. Manufacture's instructions supplied. Manufacture's instructions must not be taken as overriding statutory requirements.

CE Mark

This boiler meets the requirements of Statutory Instrument No. 3083 The boiler (Efficiency) Regulations, and therefore 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 purposes of Regulation 5 certified by: Notified body 0086.

Product/production certified by: Notified body 0086. The CE mark on this appliance shows compliance with:

1. Directive 90/396/EEC on the approximation of the laws of the Member States relating to appliances burning gaseous fuels.

2. Directive 73/23/EEC on the harmonization of the Laws of the Member States relating to the electrical equipment designed for use within certain voltage limits.

3. Directive 89/336/EEC on the approximation of the Laws of the Member States relating to electromagnetic compatibility.

Control of Substances Hazardous to Health

The adhesives and sealants used in this appliance are cured and give no known hazard in this state.

INSULATION PADS/CERAMIC FIBRE

These can cause irritation to skin, eyes and the respiratory tract. If you have a history of skin complaint you may be susceptible to irritation. High dust levels are usual only if the material is broken. Normal handling should not cause discomfort, but follow normal good hygiene and wash your hands before eating, drinking or going to the lavatory. If you do suffer irritation to the eyes or severe irritation to the skin seek medical attention. The insulation is composed of non-combustible material.

Electrical Supply

WARNING. The boiler must be earthed.

All system components shall be of an approved type and shall be connected in accordance with the current issue of BS7671 and any applicable local regulations.

External wiring must be correctly earthed, polarised and in accordance with the relevant standards.

In GB this is BS 6891. In IE this is the current edition of I.S.813 "Domestic Gas

Installations". The boiler must be connected to a permanent 230V ac, 50Hz

supply. Connection of the whole electrical system of the boiler, including

any heating controls, to the electrical supply must be through one common isolator.

Isolation should be by a double pole switched fused spur box, with a minimum gap of 3mm for both poles. The fused spur box should be readily accessible and preferably adjacent to the appliance. It should be identified as to its use.

Alternatively, an unswitched shuttered socket outlet and 3A fused 3 pin plug, both to the current issue of BS1363 may be used provided that they are not used in a room containing a bath or shower.

Wiring to the boiler must be PVC 85oC insulated cable, not less than 0.75mm2 (24/0.20mm).

Gas leak or fault

WARNING: If a gas leak or fault exists or is suspected, turn the

boiler off and consult the local gas supply company or your installation/service company.

Manual Handling Guidance

During the appliance installation it will be necessary to employ caution and assistance whilst lifting as the appliance exceeds the recommended weight for a one man lift.

In certain situations it may be required to use a mechanical handling aid.

Take care to avoid trip hazards, slippery or wet surfaces.

Heating System Controls

The heating system must be controlled as described in the relevant part of the current issue of :

Building Regulations, approved document L1, and the references:

1) GIL 59, 2000: Central heating system specification (CheSS) and

2) GPG 302, 2001: Controls for domestic central heating system and hot water. BRECSU.

3) The domestic heating and hot water guide to the building regulations 2001.

Thermostatic radiator valves may be installed, however they must not be fitted in a room where the room thermostat is located.

Air in the heating system

Persistent air in the heating system may indicate leaks in the system or corrosion taking place. Call your Installation/Servicing company.

Important Information

5 2000225065A

Protection Against Freezing

The appliance has a built in frost protection programme as long as the electricity and gas are left switched on.

Any other exposed areas of the system should be protected by a separate frost thermostat.

If the mains electricity and gas are to be turned off for any long periods during severe weather, it is recommended that the whole system, including the boiler, should be drained to avoid the risk of freezing. Make sure that, if fitted, the immersion heater in the cylinder is switched off.

This appliance operates on a sealed water system, contact your installation/servicing company as draining, refilling and pressurising MUST be carried out by a competent person.

Important Information

Draining and filling

Caution: The boiler is installed as part of a sealed system which

must only be drained and filled by a competent person. If the boiler is to be out of use for any long periods during severe

weather conditions, it is recommended that the whole system, including the boiler, be drained to avoid the risk of freezing.

If in doubt, consult your servicing company.

The cxi boilers are wall mounted modulating combination boilers with electronic ignition providing central heating and instantaneous hot water.

The boiler is of the I

category for use only with Natural Gas

(G20) . The boiler has a fan assisted balanced flue which both discharges

the products of combustion to and draws the combustion air from the outside of the room.

The boiler has a top outlet flue connection and can be fitted with horizontal flue, vertical flue or twin-pipe flue. Refer to flue options guide for further information, this is available from your nearest stockist.

Both the central heating and domestic hot water temperature are user adjustable.

Domestic hot water demand always has priority over heating demand.

The boiler is designed for use as part of a sealed water central heating system with fully pumped circulation. The pump, expansion vessel and associated safety devices are all fitted within the boiler.

The boiler can be installed against either an external wall or on an adjacent inside wall, that is, the flue system will pass directly to the rear or to either side to the terminal fitted on the outside wall face.

The installation of this boiler must be carried out by a competent person in accordance with the rules in force in the countries of destination.

Manufacturer’s instructions must not be taken as overriding statutory requirements. Reference in these instructions to British standards and statutory regulations/requirements apply only to the United Kingdom. For Ireland the current edition of I.S.813 "Domestic Gas Installations" must be used.

These instructions should be carefully followed for the safe and economical use of your boiler.

Note: The boiler serial number is marked on the data label attached to the inner front panel. The 'Operating the Appliance' section describes how to safely use the boiler.

Accessories

A range of accessories are available. For further information contact your supplier.

Draining and Filling

Appliance Introduction

BOILER DRAIN VALVE

11501

2000225065A

Overheating safety

In the event of the boiler overheating the safety devices will cause a safety shutdown. If this happens, call your Installation/ Servicing company.

Electrical supply failure

The boiler will not operate without an electrical supply. Normal operation of the boiler should resume when the electrical supply is restored.

Reset any central heating system controls, to resume normal operation.

If the boiler does not resume normal operation turn the mains reset switch off and on. If the boiler does not resume normal operation it is advisable to consult your installation / servicing company.

Pressure Relief Safety Valve

A pressure relief safety valve and discharge pipe is fitted to the boiler. This valve must not be touched. Should there be any discharge from the pipe, isolate the boiler electrical supply and call your installer or Heatcall (Glow-worm’s own service organisation) using the telephone number on the inside front cover of this booklet.

Frost protection

The appliance has a built in frost protection device that protects the boiler from freezing. With the gas and electric supplies ON and irrespective of any room thermostat setting, the frost protection device will operate the pump when the temperature of the boiler water falls below 7

The burner will fire if the temperature inside the boiler falls to 3

When the temperature reaches 10

C the boiler stops.

Any other exposed areas of the system should be protected by a separate frost thermostat.

Cleaning

WARNING: This appliance contains metal parts (components) and care should be taken when handling and cleaning with particular regard to edges of sheet metal parts to avoid any possibility of personal injury.

The boiler casing can be cleaned with a damp cloth, followed by a dry cloth to polish.

Do not use abrasive or solvent cleaners.

Maintenance and Servicing

To ensure the continued efficient and safe operation of the appliance it is recommended that it is checked and serviced as necessary at regular intervals. The frequency of servicing will depend upon the particular installation conditions and usage, refer to guarantee registration on the inside front cover of this literature.

If this appliance is installed in a rented property there is a duty of care imposed on the owner of the property by the current issue of the Gas Safety (Installation and Use) Regulations, Section 35.

Servicing/maintenance should be carried out by a competent person in accordance with the rules in force in the countries of destination.

To obtain service, please call your installer or Heatcall (Glowworm’s own service organisation) using the telephone number on the inside front cover of this literature.

Please be advised that the ‘Benchmark’ logbook should be completed by the installation engineer on completion of commissioning and servicing.

All CORGI Registered Installers carry a CORGI ID card, and have a registration number. Both should be recorded in your benchmark Logbook. You can check your installer is CORGI registered by calling CORGI direct on: 01256 372300.

Spare Parts

Remember, when replacing a part on this appliance, use only spare parts that you can be assured conform to the safety and performance specification that we require. Do not use reconditioned or copy parts that have not been clearly authorised by Hepworth Heating Ltd.

If a part is required contact Heatcall (Glow-worm’s own service organisation) using the telephone number on the inside front cover of this booklet.

Please quote the name of the appliance, this infomation will be on the name badge on the front of the appliance.

If in doubt seek advice from the local gas company or Heatcall (Glow-worm’s own service organisation) using the telephone number on the inside front cover of this booklet.

Boiler casing

CAUTION. Do not remove or adjust the casing in any way, as

incorrect fitting may result in faulty operation. If in doubt, consult your installation/service company.

Condensate Drain

The condensate drain, see section 9.2, must not be modified or blocked.

Pluming from flue terminal

This appliance will produce a plume of condensation from the flue terminal in cool weather. This is due to the high efficiency and hence low flue gas temperature of the boiler. It is normal and not a boiler fault.

Appliance Safety Devices

Maintenance and Servicing

7 2000225065A

9934

Diagram 1

FASCIA

MAINS RESET SWITCH

DIGITAL DISPLAY

CONTROL LIGHT

CENTAL HEATING WATER TEMPERATURE CONTROL KNOB

HOT WATER TEMPERATURE CONTROL KNOB

NO PRE-HEAT POSITION

ECONOMY POSITION APPROX 55O WITH PRE-HEAT

MAXIMUM POSITION APPROX 62O WITH PRE-HEAT

To Operate the Boiler

1. Check that all five isolating valves are open, see diagram 8.1.

2. A sealed pressurised system must be filled and pressurised by a competent person.

Only operate the boiler when you are sure that the system has been filled and pressurised. Check this by looking at the pressure reading on the digital display, which should read

1.0bar, see diagram 1. The digital display gives a pressure reading when there is no demand or when the appliance is in the domestic hot water mode.

3. Open a hot water tap, check that water flows, then close it.

4. If you are in any doubt about the boiler being filled with water contact your installer or Heatcall (Glow-worm’s own service organisation) using the telephone number on the inside front cover of this booklet.

5. Check that the electrical supply to the boiler is ON at the external isolator.

6. Set any remote controls as required.

7. Turn the mains reset on/off switch to the ON position (I), see diagram 1. The control light will illuminate (green) indicating the boiler is lit.

User Controls

The temperature of the domestic hot water and the central heating water can be set on the control knobs on the controls fascia, see diagram 1.

Operating the Boiler

Mains Reset Switch

0: Off. I: On. A fault is indicated by a RED flashing light on the control light

and flash fault code on digital display. To reset: Turn mains reset switch anti-clockwise to O. Wait five seconds. Turn mains reset switch to I clockwise.

Central Heating Temperature Control:

0: Temperature control is Off. I: Temperature control is On. To adjust the temperature turn the

control to the desired setting between I ‘Min’ and

‘Max’. 'Min' I is approximately 40OC (104OF). ‘Max’

is approximately 82°C (180°F).

Hot Water Temperature Control:

0: Hot water is Off. Turn selector between O and for maximum water

temperature, 62°C with no pre-heat. Turn selector between and to adjust water temperature,

40°C - 62°C with pre-heat. The ECO setting, water temperature 55°C, is the recommended

optimum position for constant use.

2000225065A

Digital Display

The digital display normally shows the operating temperature of the unit when there is a central heating demand and gives a pressure reading when there is no demand or when the appliance is in the domestic hot water mode.

If the digital display shows pressure less than 0.7bar, repressurise the system to 1bar by gently opening the built in filling tap underneath the boiler, see diagram 2. A tap extension tool is provided to facilitate this. Close the tap. If the system repeatedly loses pressure, YOU MUST CONTACT YOUR INSTALLER OR HEATCALL (GLOW-WORM’S OWN SERVICE ORGANISATION) USING THE TELEPHONE NUMBER ON THE INSIDE FRONT COVER OF THIS BOOKLET.

To Turn the Boiler Off

There is a mains/reset switch on the right hand side of the controls fascia, which will isolate the boiler. However, it is preferable to leave the electrical supply on whenever possible to permit operation of the built-in frost protection (see ‘Protection Against Freezing’) and daily pump and valve exercise.

To turn off the central heating use the room thermostat or clock/ timer.

To turn off the domestic hot water turn the domestic hot water knob to the minimum setting.

For holiday mode turn both of the temperature knobs to the minimum setting.

To turn off the boiler for servicing, isolate it from the electrical supply. To turn it on again follow the instructions given in ‘To Operate the Boiler’.

Operating the Boiler

11474

Diagram 2

FILLING LOOP TUBE

FILLING LOOP TAP AND EXTENSION TOOL

9 2000225065A

FLUE

BOILER

1 General Information

IMPORTANT NOTICE

The boiler is supplied in one pack, the flue and fixing jig are supplied seperately.

This boiler is for use only on G20 natural gas. Where no British Standards exists, materials and equipment

should be fit for their purpose and of suitable quality and workmanship.

Refer to Manual Handling Operations, 1992 regulations. The installation of this boiler must be carried out by a competent

person in accordance the rules in force in the countries of destination.

Manufacturer’s instructions must not be taken as overriding statutory requirements.

1.1 Sheet Metal Parts

WARNING: When installing the appliance, care should be

taken to avoid any possibility of personal injury when handling sheet metal parts.

1.2 Statutory Requirements

In GB the installation of the boiler must be carried out by a competent person as described in the following regulations:

The manufacturer’s instructions supplied. The Gas Safety (Installation and Use) Regulations.

The appropriate Buildings Regulations either The Building Regulations, The Building Regulations (Scotland),The Building Regulations (Northern Ireland).

The Water Fittings Regulations or Water byelaws in Scotland. The Health and Safety at Work Act, Control of Substances

Hazardous to Health (COSHH). The Current I.E.E. Wiring Regulations. Where no specific instructions are given, reference should be

made to the relevant British Standard Code of Practice. In IE, the installation must be carried out by a competent person

and installed in accordance with the current edition of I.S.813 "Domestic Gas Installations", the current Building Regulations and reference should be made to the current ETCI rules for Electrical Installation.

In GB the following Codes of Practice apply:

BS4814, BS6798, BS5440 Part 1 and 2, BS5546 Part 1, BS5449, BS6891, BS6700, BS7074 Part 1 and 2, BS7593, BS7671.

In IE: I.S.813, BS5546, BS 5449, BS 7074, BS 7593. Manufacturer’s instructions must not be taken as overriding

statutory requirements.

BSI Certification

This boiler certificated to the current issue of EN 483 : 2000 for performance and safety.

Diagram 1.1

INSIDE WALL FIXING FACE

9932

154

122

156

134

SAFETY DISCHARGE DRAIN

GAS

450

176

715

145

334

11 2000225065A

1 General Information

Diagram 1.3

9165

SCHEMATIC LAYOUT OF BOILER

1.4 Technical Data

All dimensions are given in millimetres (except as noted). See diagram 1.1 and Tables 1 and 2. The data label is positioned on the inner door, refer to diagram

1.2. The Seasonal Efficiency Domestic Boilers UK (SEDBUK) is

Class 'A' : 24cxi - 90.3%, 30cxi - 90.3% & 38cxi - 90.6%. The value is used in the UK Government's Standard Assessment

Procedure (SAP) for energy rating of dwellings. The test data from which it has been calculated has been certified by B.S.I.

1.5 Condensate Drain

A plastic drain pipe must be fitted to allow discharge of condensate to a drain.

Condensate should, if possible, be discharged into the internal household draining system. If this is not practical, discharge can be made externally into the household drainage system or a purpose designed soak away, see section 9.2 for more details.

1.6 Heating System Controls

It is recommended that a programmer and room thermostat control the boiler.

Thermostatic radiator valves may be installed, however they must not be fitted in a room where the room thermostat is located.

Note: All systems must have at least one radiator not fitted with a thermostatic valve.

Note: For further information, see the supplementary guide provided by the DTLR "Domestic heating & hot water guide" to the building regs. 2001 - part L1 and the references:

1) GIL 59, 2000: Central heating system specification (CheSS) and

2) GPG 302, 2001: Controls for domestic central heating system and hot water. BRECSU.

1.7 Vertical Plumbing Kits

Where the domestic hot water and heating flow and return pipes come from above the boiler or just the heating flow and return pipes, vertical plumbing kits are available to facilitate this.

Central Heating only, part No. 2000460477 Central Heating and DHW, part No. 2000460468 Contact Hepworth Heating for further details.

TABLE 2

APPLIANCE

BURNER %CO

24cxi

m3/h ft3/h

30cxi

RANGE RATING

38cxi

APPROXIMATE GAS RATE (after 10 mins. from cold)

MIN MAX MIN MAX MIN MAX

0.48 2.24 0.48 2.8 0.62 3.6

16.8 79 16.8 99 21.8 127

Case Off 9.1 +0.2 -0.5 Case On 9.3 +0.3 -0.5

FAN

AUTOMATIC AIR VENT

BURNER

HEAT EXCHANGER

PLA TE T O PLA TE HEAT EXCHANGER

PUMP

LOW WATER PRESSURE SWITCH

GAS CONTROL VALVE

DISCHARGE

OVERHEAT

CUT-OFF

FLOW SENSOR

RETURN

THERMISTOR

FLOW

THERMISTOR

THREE

WAY

VALVE

BYPASS

FILLING LOOP

D.H.W. COLD INLET

D.H.W. COLD INLET FILTER

C.H. INLET FILTER

D.H.W. HOT OUTLET

C.H. FLOW

C.H. RETURN

GAS

SAFETY VALVE

DRAIN TAP

DHW THERMISTOR

EXPANSION

VESSEL

2000225065A

2.1 Location

This boiler is not suitable for outdoor installation. This boiler may be installed in any room, although particular

attention is drawn to the installation of a boiler in a room containing a bath or shower where reference must be made to the relevant requirements.

In GB this is the current I.E.E. WIRING REGULATIONS and BUILDING REGULATIONS.

In IE reference should be made to the current edition of I.S.813 "Domestic Gas Installations" and the current ETCI rules.

2.2 Clearances

The boiler should be positioned so that at least the minimum operational and servicing clearances are provided, see diagram

2.1. Additional clearances may be beneficial around the boiler for

installation and servicing. For flue installations where external access is not practicable,

consideration should be given for the space required to insert the flue internally, which may necessitate clearance larger than those specified in diagram 2.1.

2.3 Timber Frame Buildings

If the boiler is to be installed in a timber frame building it should be fitted in accordance with the Institute of Gas Engineers document IGE/UP/7/1998. If in doubt seek advice from the local gas undertaking or Hepworth Heating Ltd.

2.4 Room Ventilation

The boiler is room sealed, so when it is installed in a room or space, a permanent air vent is not required.

2.5 Cupboard or Compartment Ventilation

Due to the high efficiency and hence low casing temperature of this boiler, cupboard or compartment ventilation is not necessary.

2 Boiler Location and Ventilation

Increase to 25mm clearance from combustible material.

Dimensions in millimetres

Diagram 2.1

9166

†

MINIMUM CLEARANCE FROM PERMANENT SURFACES

† A removable compartment door can be placed at least 5mm in front of the appliance.

600

220

20 20

200

13 2000225065A

3 Flue Location and Ventilation

3.1 Flue Position and Length

The standard horizontal flue is fitted onto the top of the boiler using the flue elbow.

See diagrams 3.1and 3.2 to determine whether a standard flue can be used.

An elevated flue system can be installed with the addition of extension kits, see section 3.3.

When extension pipes are used the flue system must be designed to have a continuous fall to the boiler of at least 2.5

to allow condensate to run back into the boiler and out via the drain.

3.2 Internal Flue Installation

The flue can be installed from inside the building, when access to the outside wall face is not practicable.

3.3 Flue Options

There are various flue systems to choose from, as follows: Standard horizontal flue pack - Pt. No. 2000460360 Vertical flue terminal kit - Pt. No. 2000460480 2 Metre Extension Kit - Pt. No. 2000460483 1 Metre Extension Kit - Pt. No. 2000460482

0.5 Metre Extension Kit - Pt. No. 2000460481 Adjustable Flue Pipe 0-50 mm Kit - Pt. No. 2000460487 45° Flue Bend Pack - Pt. No. 2000460485 90° Flue Bend Pack - Pt. No. 2000460484 Additional accessories are available. See Hepworth Heating “Flue Options Guide” for configurations

available.

WALL THICKNESS 'X' = 75 TO 554mm

9928

REAR FLUE - STANDARD

"X"

Diagram 3.1

Diagram 3.2

SIDE FLUE - STANDARD

DISTANCE 'Y' = 335 TO 730mm - LEFT

9935

DISTANCE 'Y' = 305 TO 730mm - RIGHT

"Y"

2000225065A

3 Flue Location and Ventilation

Diagram 3.4

TERMINAL GUARD

3.4 Terminal Position

The minimum acceptable siting dimensions for the terminal from obstructions, other terminals and ventilation openings are shown in diagram 2.1. For Ireland the minimum distances for flue terminal positioning must be those detailed in I.S.813 "Domestic Gas Installations".

The terminal must be exposed to the external air, allowing free passage of air across it at all times.

Being a condensing boiler some pluming may occur from the flue outlet. This should be taken into consideration when selecting the position for the terminal.

Carports or similar extensions of a roof only, or a roof and one wall, require special consideration with respect to any openings, doors, vents or windows under the roof. Care is required to protect the roof if made of plastic sheeting. If the carport comprises of a roof and two or more walls, seek advice from the local gas supply company before installing the boiler.

3.5 Terminal Guard

A terminal guard is required if persons could come into contact with the terminal or the terminal could be subject to damage.

If a terminal guard is required, it must be positioned to provide minimum of 50mm clearance from any part of the terminal and be central over the terminal.

The guard should be similar to that shown in diagram 3.4. A suitable guard is manufactured by: Tower Flue Components Morley Rd. Tonbridge Kent TN9 1RA. Size: 280mm x 280mm x 270mm.

MINIMUM SITING DIMENSIONS FOR FANNED FLUE TERMINALS POSITION MM

HORIZONTAL FLUES

A DIRECTLY BELOW, ABOVE OR

HORIZONTALLY TO AN OPENING, AIR BRICK, OPENING WINDOW, AIR VENT, OR ANY

OTHER VENTILATION OPENING 300 B BELOW GUTTER, DRAIN/SOIL PIPE 75 C BELOW EAVES 200 D BELOW A BALCONY OR CAR PORT 200 E FROM VERTICAL DRAIN PIPES AND

SOIL PIPES 150 F FROM INTERNAL/EXTERNAL CORNERS

OR TO A BOUNDARY ALONGSIDE THE

TERMINAL 300 G ABOVE ADJACENT GROUND OR

BALCONY LEVEL 300 H FROM SURFACE OR A BOUNDARY

FACING THE TERMINAL 600 I FACING TERMINALS 1200 J FROM OPENING (DOOR/WINDOW)

IN CAR PORT INTO DWELLING 1200 K VERTICAL FROM A TERMINAL 1500 L HORIZONTALLY FROM A TERMINAL 300

VERTICAL FLUES

M FROM ADJACENT WALL TO FLUE 300 N FROM ANOTHER TERMINAL 600 P FROM ADJACENT OPENING WINDOW 1000 Q ABOVE ROOF LEVEL 300

Diagram 3.3

B,C

UNDER CAR PORT etc.

H,I

11508

15 2000225065A

Table 3. Flow Rate

MODEL MINIMUM FLOW RATE 24 cxi 774 litres/hr. 30 cxi 1032 litres/hr. 38 cxi 1289 litres/hr.

This is equal to 20OC differential at maximum heat input.

4.1 General

The boiler is for use only with sealed central heating systems. The safety valve is an integral part of the boiler and it cannot be

adjusted. The digital readout on the controls fascia indicates the system

pressure when there is no central heating demand. The circulation pump is integral with the boiler.

4.2 Expansion Vessel

The boiler has an integral expansion vessel with a capacity of 8 litres (1.76 gallons), with a charge pressure of 0.5bar.

Note: The expansion vessel volume depends on the total water system volume and the initial system design pressure. Guidance on vessel sizing is also given in the current issue of BS5449 and BS7074 Part 1, for IE refer to the current edition of I.S.813 "Domestic Gas Installations".

4.3 Flow Rate

If it is necessary to alter the flow rate, the system can be fitted with a lockable balancing valve in the main flow or return pipes shown as valve “A” in diagram 4.1. The flow rate through the boiler must not be allowed to fall below that given in table 3.

4.4 Bypass

The boiler is fitted with an adjustable automatic bypass. Ensure that under no circumstances does the flow rate drop below the figure specified, refer to table 3 and section 11.6.

4 Heating System

2000225065A

BOILER

DOMESTIC

WATER

HOT OUT

COLD SUPPLY IN

DRAIN POINT

'A'

FLOW CONTROL VALVE

HEATING CIRCUIT

RETURN

ADDITIONAL EXPANSION VESSEL (if required)

Filling device

* BYPASS (if required)

4 Heating System

Diagram 4.1

9168

The installation of the boiler must comply with the requirements of the current issue of BS6798, in Ireland, refer also to the current edition of I.S.813 "Domestic Gas Installations".

In GB it is necessary to comply with the Water Supply (Water Fittings) Regulations 1999 (for Scotland, the Water Byelaws 2000, Scotland).

To comply with the Water regulations your attention is drawn to: The Water Regulations guide published by the Water Regulations Advisory Service (WRAS) gives full details of the requirements.

In IE the requirements given in the current edition of I.S.813 "Domestic Gas Installations" and the current Building Regulations must be followed.

Diagram 4.2

11474

FILLING LOOP TAP

FILLING LOOP TAP EXTENSION

* Refer to section 11.6

4.5 Filling the Sealed System

The boiler has a built in filling loop, see diagram 4.2. To ease access to the filling loop tap, push on the tap extension piece, supplied in loose items pack, see diagram 4.2. Open the filling loop tap to pressurise the system to 1 bar indicated on the digital display with no demand.

Note that the electrical supply to the appliance has to be switched on to enable the pressure to be read in the digital display.

Refer to section 11.2 for filling procedure. On filling the system a small amount of water maybe discharged

from the reduced pressure zone valve, see diagram4.2.

4.6 Water Treatment

In the case of an existing installation, it is ESSENTIAL that prior to installing the new boiler the system is thoroughly flushed. For optimum performance after installation of a new system, the boiler and its associated central heating system should also be flushed. Flushing should be carried out in accordance with BS7593: 1992 using a cleanser such as Sentinel X300 or X400, Fernox Superfloc or Salamander corrosion guard cleaner.

For long-term corrosion protection, after flushing, an inhibitor suitable for stainless steel exchangers should be used, refer to the current issue of BS 5449 and BS 7593 on the use of inhibitors in central heating systems. Examples are Sentinel X100 Fernox or Salamander corrosion guard inhibitor.

4.7 Draining Tap

A draining tap must be provided at the lowest points of the system, which will allow the entire system to be drained.

A drain tap for the appliance is provided as an integral part of the hydroblock, see diagram 12.11.

REDUCED PRESSURE ZONE VALVE

17 2000225065A

5 Domestic Hot Water System

General - All domestic hot water circuits, connections, fittings

must be in accordance with the relevant standards and water supply regulations.

For GB: Guidance G17 to G24 and recommendation R17 to R24 of the Water Regulations Guide.

For IE: The current edition of I.S.813 "Domestic Gas Installations".

5.1 Water Pressure

The maximum working pressure of the domestic hot water circuit is 10 bar. If the cold water supply pressure exceeds this, then a pressure-reducing valve must be fitted in the supply to the boiler.

5.2 ‘Hard’ Water Areas

The temperatures within the heat exchanger are limited by the boiler control system to minimise scale formation within the hot water pipework. However, in areas where the water is ‘hard’ (i.e. more than 200mg/litre), it is recommended that the hot water setting is reduced and that a scale reducer is fitted.

Refer to the manufacturer’s instructions or consult the local water company for additional advice.

5.3 Domestic Water Flow Rate

The water flow rate is restricted to a maximum 10 l/min (24cxi) 12 l/min (30cxi) and15.5 l/min (38cxi) by a restrictor fitted during boiler installation, see diagram 8.2.

2000225065A

Diagram 6.1

9169

WALL TEMPLATE

EXTENDED SIDE FLUE

Ø 125

6 Installation Preparation

6.1 Unpacking of Boiler

IMPORTANT: With regards to the Manual Handling Operations,

1992 Regulations, the following lift operation exceeds the recommended weight for a one man lift.

Stand the boiler carton upright. Cut and remove the securing straps and lift off the carton

sleeve. Place aside any loose components until required. Carefully lay the boiler on its back, remove the two front casing

panel securing screws and lift off the panel from two retaining lugs, see diagram 6.3.

Remove the two inner casing panel securing screws at the bottom front of the panel, then lift off the two retaining lugs, see diagram 6.3.

6.2 Wall Template

Remove the wall template from the wall mounting pack and place in the desired position on a flat wall, giving due consideration to boiler clearances, see section 2.2.

6.3 Flue Hole Cutting

The standard horizontal flue is designed with an internal fall of 35mm/metre towards the boiler for disposal of condensate. If the standard flue length alone is being used then the flue hole of diameter 105mm can be cut in the position marked on the wall template.

For standard side flues the horizontal flue centre line on the wall template should be extended to the side wall, and the vertical centre of the flue hole marked at 176mm from the back wall.

For installations with external access, a 105mm diameter core drill can be used.

For installations with internal access only a 125mm diameter core drill should be used.

When using extension pipes with the horizontal rear flue, a core drill size of 125mm should be used to allow the extension pieces to slope at 35mm/metre (2.5

) towards the boiler.

176

Diagram 6.2

9170

WALL PLUG

SCREW

WALL TEMPLATE

HANGING BRACKET

FIXING JIG PLATE

FIXING JIG WALL BRACKETS (2 OFF) (Handed as shown)

SCREW (2 OFF)

SCREW

WALL PLUG

For extended side flues, the flue hole centre should be determined by extending the dashed inclined line on the template to the side wall. This dashed line is drawn at 35mm/metre (2.5

) rise from the boiler. Where this line reaches the side wall, a horizontal line should be marked. The vertical centre line of the flue should then be marked at 176mm from the back wall, see diagram 6.1.

To allow for the flue passing through the wall at this angle a 125mm hole should be drilled irrespective of internal or external installation.

If necessary remove the wall template whilst drilling the flue hole.

19 2000225065A



6 Installation Preparation

Diagram 6.3

9171

SECURING SCREW (2 OFF)

FRONT CASING PANEL

RETAINING LUG (2 OFF)

6.4 Fixing Jig and Hanging Bracket Fixing

If previously removed, reposition the wall template over the flue hole and mark the position of the fixing holes for the jig and the hanging bracket, see diagram 6.2.

Drill the four fixing holes and insert suitable wall plugs. If gas and/or water pipes are to be plumbed through the rear

wall directly into the fixing jig holes, the holes must be drilled as marked on the wall template prior to fixing of the fixing jig.

Fix the wall products to the wall using suitable screws. Locate the jig plate between the wall brackets and secure with the screws supplied.

6.5 Pre-Plumbing

The fixing jig can now be pre-plumbed without the boiler being mounted. All water and gas connections are on the fixing jig with the exception of the condense drain and safety discharge, the positions of these are shown on the wall template for pre plumbing purposes. See sections 8 and 9 for details of gas, water, condensate connections.

Do not route any pipes behind the boiler, unless a vertical piping kit is used.

For vertical plumbing of the central heating or DHW pipes it is preferable to use the Glow-worm vertical plumbing kits, see section 1.7.

INNER CASING PANEL

LOCATING HOLES

10068

SECURING SCREW (2 OFF)

2000225065A

7 Flue Preparation

7.1 Flue Length

All dimensions are in mm. For rear or side flue, measure the distance from the outside wall

to the butt joint of the flue elbow fitted on top of the boiler. A standard flue system will be suitable if the length measured ‘Y’ is less than 633mm, see diagrams 7.1 and 7.2.

If the measurement ‘Y’ exceeds 633mm then one or more extension pipes are required.

When cutting, the flue duct should be cut flush with the air duct.

7.2 Extension pipes

Refer to diagrams 7.3 and 7.4. Note maximum permitted lengths When extension pipes are required it should be noted that the

length of the air ducts which butt together are 960mm long and this should be taken into account when calculating the length that requires cutting.

For example: Distance from outside wall to butt joint on the flue elbow ‘Y’ =

2700 mm. Standard flue length = 633 mm. Extension pipe length = 960 mm. Length required of final extension pipe = 2700 - (633 + 960 + 960) = 147mm. In this example the final extension pipe would be cut to 147mm,

this would be measured from the end of the air duct where the flue duct contains the ‘O-ring’ seal.

When cutting, the flue duct should be cut flush with the air duct at the opposite end to where the flue duct contains the ‘O-ring’ seal.

The system is made up from a standard horizontal flue kit and accessories. The accessories include flue extensions, 45

and

bends and fixing brackets.

The maximum permitted straight flue length is 10 metres plus the standard horizontal flue. For each 90

or 2 x 45o bends fitted,

the maximum length must be reduced by 1 metre. Note: 2 x 45

bends can replace 1 x 90o if necessary. When

using 90

bends any horizontal extension pipe should be

inclined by a minimum of 2.5

fall towards the boiler to facilitate

condense removal.

7.3 Flue Assembly

The flue assembly is a push fit design with securing collars. Remove all burrs from cut pipes. Diagram 7.5 shows the components supplied in the standard kit

and the flue adapter. Having cut the air and flue ducts as described in sections 7.1-

7.2 assemble the flue as follows, the flue can be fitted externally or entirely from inside.

Fit the rubber sealing collar behind the locating lugs on the flue terminal, see diagram 7.5.

Push the flue assembly into the wall, externally or internally, initially until the end of the assembly protrudes a short way from the inside face of the wall. This will enable the inner rubber sealing collar to be positioned and allow the flue duct to be drawn back into the flue elbow after the boiler has been mounted.

Diagram 7.1

OUTSIDE WALL FACE

Diagram 7.2

STANDARD SIDE FLUE

9304

9313

REAR FLUE

DRILL AND SCREW

BOILER MOUNTING WALL

Diagram 7.3

SIDE FLUE EXTENSION

9305

DRILL AND SCREW

21 2000225065A

7 Flue Preparation

7.4 Flue Attachment To Boiler

Refer to section 8 and fix the boiler in position prior to completing the flue installation.

Refer to diagram 7.5. Secure the flue adapter in position on top of the boiler with four torque headed screws supplied, making sure the nib fits into the locating slot in the boiler casing to ensure correct orientation.

Fit the flue elbow with the securing collar (length 40mm) on to the flue adapter.

Secure the flue elbow by tightening up the two screws on the securing collar.

Draw flue assembly from wall, fit securing collar (length 70mm), slide flue duct into flue elbow.

Note: If the air and flue ducts has been correctly cut to the

instructions given in sections 7.1-7.2 the rubber sealing collar should fit flush with the outside wall, check this.

Position securing collar centrally over joint, tighten securing screws. Drill and insert four self-tapping screws, supplied, in the holes provided in the securing collar

Diagram 7.5

9931

AIR DUCT

FLUE ELBOW

GROOVE

SEALING COLLAR

FLUE TERMINAL

SEALING COLLAR

FLUE DUCT

SECURING COLLAR (70mm)

SECURING COLLAR (40mm)

FLUE ADAPTER

Diagram 7.4

EXTENDED HORIZONTAL FLUE

ELEVATED HORIZONTAL FLUE

10083

X + Y must not exceed 10 metres plus standard horizontal flue kit.

Reduce flue length by 1 metre for every additional 900 or 2 x 45

bends.

Total flue length must not exceed 10 metres plus standard horizontal flue kit.

Reduce flue length by 1 metre for every additional 900 or 2 x 450 bends.

2000225065A

WALL MOUNTING JIG

GAS SERVICE COCK

Diagram 8.1

CENTRAL HEATING RETURN

DOMESTIC HOT WATER OUT

CENTRAL HEATING FLOW

DOMESTIC COLD WATER SUPPLY IN

9172

ISOLATING VALVE

GAS SUPPLY PIPE IN

ALL VALVES SHOWN IN CLOSED POSITION

8 Gas/Water Connections and Boiler Fixing

DOMESTIC HOT WATER INLET VALVE

8.1 Gas Connection

Before connection check supply of local gas. The gas supply can be connected from below or through the

wall at the rear of the boiler, the position is shown on the wall template.

Refer also to section 1.2. Fit the sealing washer into the securing nut and make good the

final connection to the gas service cock on the wall mounting jig, see diagram 8.1.

Do not subject the gas service cock to heat. Make sure the on /off lever is accessible. The whole of the gas installation, including the meter, should be

inspected, tested for soundness and purged in accordance with the current issue of BS6891 and in IE the current edition of I.S.813 "Domestic Gas Installations".

8.2 Water Connections

Provision is made for the water connections to be made from below or through an internal wall at the rear of the boiler, the position is shown on the wall template. Copper tailpieces are supplied in the wall mounting pack.

Flush out the domestic hot water and the heating systems before connecting to the boiler.

Make the connections to the domestic hot water and heating systems by fitting the sealing washers into the securing nuts and make good the final connection to the isolating valves on the wall mounting jig, see diagram 8.1.

Do not subject the isolation valves to heat. Make sure the drain point is accessible.

ON/OFF LEVER

SAFETY VALVE DISCHARGE PIPE

CENTRAL HEATING FLOW AND RETURN

GAS SERVICE COCK

'B' SEALING WASHERS AND UNION NUTS (5 OFF)

'A' SEALING WASHER AND UNION NUT

11478

23 2000225065A

9.1 Safety Valve Discharge

The pipe from the safety valve must not discharge above an entrance, window or any type of public access area.

A short discharge pipe is supplied loose with the boiler fittings pack. This must be extended, using not less than 15mm o.d. pipe, to discharge, in a visible position, outside the building, facing downwards, preferably over a drain, see diagram 8.1.

The pipe must have a continuous fall and be routed to a position so that any discharge of water, possibly boiling, or steam cannot create any danger to persons, damage to property or external electrical components and wiring.

To ease future servicing it is advisable to use a compression type fitting to extend the discharge pipe.

9.2 Condensate Drain Connection

The condensate drain connection is behind the pump at the rear of the boiler, see diagram 9.1. An adaptor for 21.5mm plastic overflow pipe is supplied loose with the boiler fittings pack and should be used to fit on to the drain connection, if required, to discharge condensate to a drain. The drain pipe should have a fall of a least 2.5

away from the boiler.

Condensate should, if possible be discharged into the household internal drainage system. If this is not practicable, discharge can be allowed into the external household drains or a purpose designed soak away.

It is recommended that any external condensate drain pipe is insulated and also preferably of 32mm diameter, to prevent freezing in adverse weather conditions.

The condensate is discharged periodically in ‘slugs’ by siphonic action.

Diagram 9.1

11482

CAP

CONDENSATE DRAIN

DRAIN CONNECTION

9 Safety Valve Discharge and Condensate Connections

8 Gas/Water Connections and Boiler Fixing

IMPORTANT: With regards to the Manual Handling Operations,

1992 Regulations, the following lift operation exceeds the recommended weight for a one man lift.

Having previously secured the wall mounting jig and hanging bracket to the wall, lift the boiler into position in the following manner.

Lean the top of the boiler slightly to the wall and position just above the hanging bracket. Allow the boiler to slowly move downwards until engaged in the hanging bracket.

Slowly swing the base of the boiler to the wall mounting jig ensuring that the connections on the boiler line up with the 'A' gas and 'B' water isolation valves on the jig, see diagram 8.1. Fit sealing washers into the securing nuts and make good the final connections.

Fit the flow restrictor to the domestic cold water inlet cock, see diagram 8.2.

Please refer to condensate connection before proceeding, see section 9.2.

Attach the flue as described in section 7.6.

Diagram 8.2

11479

RETAINING WIRE

DOMESTIC COLD WATER IN ISOLATING VALVE

UNION NUT

COLD WATER INLET RESTRICTOR

UNION NUT

It is not necessary to provide air breaks or extra traps in the discharge pipe as there is already a 75mm high trap inside the boiler. Fitting an extra trap may cause the boiler siphon to work incorrectly.

Refer to BS5546 or BS6798 for advice on disposal of boiler condensate.

2000225065A

CONTROL PANEL REAR COVER

SECURING SCREW (3)

10181

CABLE EXIT

CONTROL PANEL REAR COVER

VOLTAGE FREE HEATING CONTROLS CONNECTION

WIRE LINK (E)

11506

10 Electrical Connections

WARNING: This appliance must be earthed. This appliance

must be wired in accordance with these instructions. Any fault arising from incorrect wiring cannot be put right under the terms of the Glow-worm guarantee.

All system components must be of an approved type. Electrical components have been tested to meet the equivalent

requirements of the BEAB. Do not interrupt the mains supply with a time switch or

programmer. Connection of the whole electrical system and any heating

system controls to the electrical supply must be through a common isolator.

Isolation should preferably be by a double pole switched fused spur box having a minimum contact separation of 3mm on each pole. The fused spur box should be readily accessible and preferably adjacent to the boiler. It should be identified as to its use.

A fused three pin plug and shuttered socket outlet may be used instead of a fused spur box provided that:

a) They are not used in a room containing a fixed bath or shower.

b) Both the plug and socket comply with the current issue of BS1363.

10.1 Mains Cable

Important: If a replacement supply cable is required it must be

purchased. Part No. S1008600.

10.2 Voltage Free System Controls

WARNING: UNDER NO CIRCUMSTANCES MUST ANY

MAINS VOLTAGE BE APPLIED TO ANY OF THE TERMINALS ON THE VOLTAGE FREE HEATING CONTROLS CONNECTION PLUG.

This boiler will operate continuously on heating as supplied, if the wire link (E), fitted between the two terminals of the heating controls connection, is left in place, see diagram 10.1.

System heating controls e.g. Room thermostat, should be fitted in accordance with the rules in force.

Refer to diagram 10.2.

Diagram 10.2

Diagram 10.1

230V~ 50Hz

PERMANENT

MAINS SUPPL

3 AMP FUSE

DOUBLE POLE

ISOLATOR

LNE

ROOM

THERMOSTAT

DO NOT

CONNECT

PROGRAMMER VOLTAGE FREE

ROOM THERMOST A T

3 2 1

TO MAIN PCB

CONNECTOR J15

PROGRAMMER

VOLTAGE FREE

HEATING CONTROLS

CONNECTION

(ON CONTROLS

BOX COVER)

ON/OFF SWITCH

CONTROLS

INTERFACE PCB

BOILER

11994

25 2000225065A

10 Electrical Connections

Diagram 10.3

Diagram 10.5

10.3 Mains Voltage System Controls

WARNING: UNDER NO CIRCUMSTANCES MUST ANY

MAINS VOLTAGE BE APPLIED TO ANY OF THE TERMINALS ON THE VOLTAGE FREE HEATING CONTROLS CONNECTION PLUG.

Remove the MAINS VOLTAGE HEATING CONTROLS CONNECTION PLUG from the fittings pack and install on the control interface PCB as follows.

Gain access to the control and user interface PCB 's by unclipping the fascia panel and hinging forward, see diagram

10.3. Route the system controls cable and connect to the plug

, see

diagram 10.3. Insert plug onto controls interface PCB, see diagram 10.3. Close the fascia panel and remove the screws to open the rear

cover of control panel, see diagram 10.1. Secure the system control cable in the strain relief, and thread

the cable through rear of the control panel and out of the cables exit, see diagram 10.4.

Close and secure rear cover of control panel. Remove the wire link from the voltage free heating controls

connector, see diagram 10.1. Connect system controls as diagram 10.5. External controls should be fitted in accordance with the rules

in force.

10.4 Electrical Connections - Testing

Carry out preliminary electrical system checks as below:

1. Test insulation resistance to earth of mains cables.

2. Test the earth continuity and short circuit of cables.

3. Test the polarity of the mains. Please ensure the “Benchmark” logbook is completed and left

with the user and the magnetic lighting instruction label is placed on the surface of the boiler casing.

PLUG

SYSTEM CONTROLS CABLE ( MAINS VOLTAGE)

RETAINING LATCHES

11472

11408

230V~ 50Hz

PERMANENT

MAINS SUPPL

3 AMP FUSE

DOUBLE POLE

ISOLATOR

JUNCTION BOX

LNE

FROST

THERMOSTAT

ROOM

THERMOSTAT

DO NOT

CONNECT

OPTIONAL BUILT-IN PROGRAMMER

230V ac ROOM THERMOSTAT

230V ac FROST THERMOSTAT

3 2 1

REMOVE LINK

WHEN SYSTEM

CONTROLS ARE USED

TO MAIN PCB

CONNECTOR J15

VOLTAGE FREE

HEATING CONTROLS

CONNECTION

(ON CONTROLS

BOX COVER)

MAINS VOL TAGE

HEATING CONTROLS

CONNECTION PLUG

ON/OFF

SWITCH

CONTROLS

INTERFACE PCB

BOILER

PROGRAMMER

230V~ 50Hz

PERMANENT

MAINS SUPPL

3 AMP FUSE

DOUBLE POLE

ISOLATOR

JUNCTION BOX

LNE

FROST

THERMOSTAT

ROOM

THERMOSTAT

DO NOT

CONNECT

PROGRAMMER

230V ac ROOM THERMOSTAT

230V ac FROST THERMOSTAT

3 2 1

REMOVE LINK

WHEN SYSTEM

CONTROLS ARE USED

TO MAIN PCB

CONNECTOR J15

PROGRAMMER

VOLTAGE FREE

HEATING CONTROLS

CONNECTION

(ON CONTROLS

BOX COVER)

MAINS VOL TAGE

HEATING CONTROLS

CONNECTION PLUG

ON/OFF

SWITCH

CONTROLS

INTERFACE PCB

BOILER

STRAIN RELIEF

MAINS CABLE

Diagram 10.4

CABLE EXIT

SYSTEM CONTROLS CABLE

11993

11992

2000225065A

Diagram 11.3

9531

BYPASS VALVE

ADJUSTMENT SCREW

11 Commissioning

11.1 Filling Domestic Water Circuit

Fully open any valves in the domestic water supply to the boiler. Open the domestic water isolation valve, slot in line with the

length of the valve, see diagram 8.1. Open all hot water taps in turn and close them when water flows.

Check for water soundness of the complete domestic water system.

The water flow rate is restricted to a maximum 10 l/min (24cxi) 12 l/min (30cxi) and15.5 l/min (38cxi) by a restrictor fitted during boiler installation, see diagram 8.2.

11.2 Filling the Heating Circuit

Open the two central heating isolating valves and domestic cold water inlet valve, slots in line with the length of the valve, see diagram 8.1

To enable the system pressure to be viewed, turn the Central heating temperature knob and hot water temperature knob to the off position.

Turn the mains electricity supply on to the appliance and ensure that the mains switch on the appliance fascia is set to the on position.

The system pressure should be viewed on the digital display on the front of the appliance, see diagram 1.

Pressurise the system by opening the tap of the inbuilt filling loop, see diagram 4.2. Fill the system until the pressure on the display reads at least 1.0bar. Note that on filling the system a small amount of water may be discharged from the reduced pressure zone valve, see diagram 4.2.

Make sure that the automatic air vent works correctly and that the black cap is loosely fitted to allow air to escape, see diagram

11.1. Check the heating system and boiler connections for water

soundness.

11.3 Preparation for Lighting

Isolate the boiler from the mains electrical supply. Test for gas soundness and purge air from the gas supply. Turn

on the gas service cock, see diagram 8.1.

11.4 Initial Lighting

The lighting procedure of the boiler is fully automated. Check that all external controls are calling for heat. If an integral

clock/timer is fitted check that it is correctly programmed and if necessary overridden to provide heat.

Ensure that both the central heating and the domestic hot water control knobs are turned OFF.

Turn on the mains electrical supply and the mains reset knob to (I) on the controls fascia.

Turn the central heating hot water knob to (I) MINIMUM. The digital display will show water temperature in central

heating demand. The fan should start and after a few seconds the ignition will

commence If the burner fails to light the fan will stop. Initially this may be due

to air in the gas supply line. The boiler will automatically have three attempts at ignition.

If necessary turn the reset switch to the off position (O), then back to the on position (I) and the boiler will restart.

After the boiler has lit, allow to warm at minimum temperature setting to purge any air from the system.

Once the system has been purged of air turn the Domestic hot water control knob to the desired position and open a hot water tap. The three way valve will move to hot water supply and the display will read system pressure. Check that hot water is available and then close the hot water tap.

Turn the central heating knob to the desired temperature. The appliance will then continue to fire in central heating until

the user controls are satisfied or there is another demand made for hot water.

Diagram 11.2

Diagram 11.1

CAP

AUTOMATIC AIR VENT

PUMP

ELECTRICAL PLUG

GAS CONTROL VALVE

PRESSURE TEST POINT

11481

11483

27 2000225065A

11 Commissioning

Note that after first power up the firing sequence for central heating changes. After one minute stabilisation time the boiler will ramp slowly to full rate rather than going immediately to full rate. This is an adaptive feature to cope with small system requirements.

11.5 Testing - Gas

Should any doubt exist about the gas rate, check it using the gas meter test dial and stop watch at least 10 minutes after the burner has lit, making sure that all other gas burning appliances and pilot lights are off.

The approximate gas rates: 24cxi : 2.24m

/h (79ft3/h)

30cxi : 2.8m

/h (99ft3/h)

38cxi : 3.6m3/h (127ft3/h) are for guidance only. The gas valve is factory set and should need no adjustment. It

should be checked that the supply pressure is 20mbar when the boiler is firing at full rate. This can be achieved by turning on several hot water taps and checking the inlet pressure at the tapping on the gas valve shown in diagram 11.2. Turn taps off and disconnect pressure gauge.

Note that the burner pressure cannot be measured at the gas valve as it is altered by the suction of the fan and modulated according to demand.

11.6 Testing - Heating System

Check that all remote controls are calling for heat. The boiler will fire automatically. Fully open all radiator valves, flow control valve ‘A’, if fitted, see diagram 4.1.

Balance the radiators as required and if fitted adjust valve ‘A’ to give the required system differential. Turn off all radiators that can be shut off by the user and check to see if less than the maximum differential allowed of 20

C can be achieved across

flow and return. This boiler has a built in bypass, see diagram 11.3. The boiler is supplied with the bypass open half a turn. It should

not be necessary to adjust the bypass, but if required turn the adjustment screw clockwise to close the valve, see diagram

11.3. Allow the system to reach maximum temperature then switch

off the boiler by isolating from the electrical supply. Drain the entire system rapidly whilst hot, using the drain tap at

the lowest part of the system. Fill and vent the system as described previously in section 11.2.

Lock or remove the handle from control valve ‘A’, if fitted. Replace inner casing panel and front casing panel.

11.7 User Controls and Options

The mains reset on/off switch is used to restart the boiler after a fault condition has occurred, i.e. ignition failure, low water pressure or high water temperature.

The central heating and domestic hot water control knobs allow the user to set the temperatures in each mode.

Note: If there is no demand the digital display shows the water pressure.

Temperature Display

The digital display normally shows the operating temperature of the unit when there is a central heating demand.

Holiday Mode

Normal mode uses the domestic hot water and central heating temperatures selected.

By turning the domestic hot water and central heating control knobs to minimum setting the holiday mode is set up. However, frost protection and pump exercise programme remain active. By doing this the DHW will operate without pre-heat and DHW will set at maximum temperature. To resume normal operation after a holiday period, return the control knobs to their original position.

11.8 Pump Exercise Program

After a power cut or every 24 hours in holiday mode the three way valve will switch and the pump will run to prevent the components from sticking. This will also occur during normal operating if there is no domestic or central heating demand for more than 24 hours.

11.9 Frost Protection

The boiler has a built in frost protection programme as long as the electricity and gas are left switched on.

This device operates the appliance pump when the temperature inside the boiler falls below 7°C and circulates water around the appliance only.

If the temperature falls to 3°C the burner is lit and water circulates around the heating system.

When the temperature inside the appliance reaches 10°C the burner will shut down and after a short period the pump will stop.

This device primarily protects the boiler. Any other exposed areas of the system should be protected by a separate frost thermostat.

11.10 Instruct the User

Instruct and demonstrate the lighting procedure and advise the user on the safe and efficient operation of the boiler.

Instruct on and demonstrate the operation of any heating system controls.

Advise the user on the use and maintenance of any scale reducer and pass on any relevant instructional documents.

Advise that to ensure the continued efficient and safe operation of the boiler it is recommended that it is checked and serviced at regular intervals. The frequency of servicing will depend upon the installation conditions and usage, but in general, once a year should be enough.

Draw attention, if applicable, to the current issue of the Gas Safety (Installation and Use) Regulations, Section 35, which imposes a duty of care on all persons who let out any property containing a gas appliance in the UK.

It is the Law that any servicing is carried out by a competent person.

Advise the user that, like all condensing boilers this appliance will produce a plume of condensation from the flue terminal in cool weather. This is due to the high efficiency and hence low flue gas temperature of the boiler.

Advise the user of the precautions necessary to prevent damage to the system, boiler and the building, in the event of the heating system being out of use during frost or freezing conditions.

Advise the user that the permanent mains electrical supply SHOULD NOT be switched off, as the built in frost protection and pump/valve saver program would not be operable.

Reminder, leave these instructions and the ‘Benchmark’ logbook with the user.

For IE, it is necessary to complete a "Declaration of Conformity" to indicate compliance to I.S.813. An example of this is given in the current edition of I.S.813.

2000225065A

12 Servicing

12.1 General

Refer to Table 2 Section 1 General Information. Measurement of the products of combustion can be achieved by connection of a probe to the combustion analyser test point, see diagram

12.1. Before commencing with a service or replacement of parts the

boiler should be isolated from the electrical supply and the gas supply should be turned off at the gas isolation valve, see diagram 8.1.

All routine servicing requirements can be achieved by the removal of the front panel and inner panel only. To remove simply undo the two screws on the underside of the front panel and lift off, see diagram 6.3. Undo the two screws on the front of inner panel and lift off, see diagram 6.3.

Unless stated otherwise any part removed during servicing should be replaced in the reverse order to removal.

Servicing should always include the removal of any debris from the condensate pipe and siphon.

After completing any servicing of gas carrying components, ALWAYS test for gas soundness and carry out a functional test of the controls.

12.2 Spark Electrode

Disconnect the electrode lead and two securing screws. Withdraw the spark electrode carefully from the combustion chamber, see diagram 12.2 and 12.5.

Inspect the tips for damage. Clean away any debris and check the spark gap is 3.5 to 4.5

mm. Check the electrode gasket for signs of damage and replace if

necessary.

12.3 Burner

Drop down the control panel into the service position, see diagram 12.13.

Disconnect the gas supply at the gas service cock, see diagram

8.1. Remove the two gas pipe retaining clips, one located below gas

valve and the other one located on the underside of the boiler chassis, see diagram 12.4.

Pull sealing grommet down gas pipe, see diagram 12.4. Push the gas pipe upwards further into gas valve connection

and then rotate anti-clockwise (looking down) until the gas pipe end is over the large hole in boiler chassis, see diagram 12.4.

Withdraw the gas pipe from gas valve connection and remove. Note: When replacing ensure that the sealing grommet, situated

below the gas valve is correctly re-seated. Disconnect the gas control valve electrical plug at the gas

control valve. Disconnect the electrical leads from the fan. Remove the five combustion chamber front retaining nuts, see

diagram 12.5. Gently remove the fan, gas control valve and burner assembly

from the combustion chamber, see diagram 12.3.

SECURING SCREW 2 OFF

SPARK GAP 3.5 to 4.5

Diagram 12.2

HEAT EXCHANGER

ELECTRODE

GASKET

Diagram 12.1

COMBUSTION ANALYSER TEST POINT

FLUE ELBOW

Diagram 12.3

BURNER

COMBUSTION CHAMBER

FAN GAS CONTROL

VALVE

SEALING RING

EARTH LEAD

11410

11484

11502

29 2000225065A

12 Servicing

Clean the burner with a soft brush taking great care not to damage the front insulation. DO NOT use wire or sharp instruments to clean the holes of the burner.

Inspect the burner for any signs of damage. Inspect the sealing rings and replace if necessary. Removal of the burner is not necessary during a normal service. NOTE: IF THE BURNER HAS TO BE REMOVED IT WILL

REQUIRE A NEW GASKET WHEN REFITTED.

12.4 Combustion Chamber and Heat Exchanger

Refer to diagram 12.3. Remove loose debris from combustion chamber using a soft

brush and vacuum cleaner. Carefully flush by spraying water any remaining debris through the condensate trap (Ensure the water is kept away from electrical components).

12.5 Condensate Drain

Refer to diagram 12.8. Remove the clips securing the flexible tubes to the siphon

adapter by twisting the clips slightly to disengage the clip jaws from each other.

Remove black flexible tubes from siphon adapter. Lift off the siphon adapter. Remove the drain connection downstream of the condense

drain. Remove DC fan supply, refer to section 14.5. Remove the condense trap securing screws. Lift up and carefully remove the condense drain taking care not

to spill any water which may be in the unit. As the unit is lifted remove the flexible connection on the outlet.

Remove the cap at the base of the condense trap. Remove any solids found. Remove the float to clean it. Flush water through the trap to remove any remaining solids. Check for any debris in the outlet pipe of the condensate drain

and clean as necessary. Reassemble and refit the condensate drain. When refitting the cap ensure that a watertight seal is achieved,

but do not use excessive force. Remove siphon adapter from flexible tubes. Using a suitable container flush the heat exchanger by spraying

water until the water appears clear in the container. Refit the siphon adapter and flexible connections.

Diagram 12.4

HEAT EXCHANGER

SECURING NUT (5 OFF)

ELECTRODE LEAD

Diagram 12.5

GAS CONTROL VALVE

GAS PIPE RETAINING CLIP

SPADE CONNECTOR

SEALING GROMMET

11490

GAS SERVICE COCK

GAS PIPE RETAINING CLIP

11481

11478

2000225065A

12 Servicing

12.6 Combustion Check.

If a gas carrying component has been replaced, the combustion of the appliance should be checked as follows. Once the appliance has been re-assembled (apart from the front and inner casing panels) connect a CO

combustion analyser to the

test

point on the flue adapter, see diagram 12.1. Turn on the gas service cock, see diagram 8.1. With the power off and the appliance cold, unclip the controls

fascia and hinge it down to reveal the potentiometers on the rear of the User interface, see diagram 12.7. Take care not to allow the fascia to drop down and damage the wiring.

Turn on the electrical supply. Ensure external controls are calling for heat. The boiler should

fire automatically. Allow the boiler to fire for a minimum of 60 seconds and then,

using an electrical screwdriver, rotate the service potentiometer fully clockwise, see diagram12.7. This will allow the digital display to indicate the ‘flashing’ fan speed on the appliance fascia.

In the fully clockwise position the display should be indicating the maximum fan speed of the appliance, in central heating mode this should be 39 for 24cxi, 45 for 30cxi and 45 for 38cxi. With domestic hot water max. demand this should be 51 for 24cxi, 57 for 30cxi and 57 for 38cxi. Check the CO

value, which

should be 9.1% +0.2 -0.5

Note that with the inner case front panel fitted the combustion readings will increase slightly to 9.3% +0.3 -

0.5.

If adjustment proves necessary then proceed as follows. Any adjustment to the gas valve should only be carried out by

a qualified person. Refer to diagram 12.6. Adjust the maximum rate CO2 with the throttle to 9.1%. (Rotate

anti-clockwise to increase).

Diagram 12.6

THROTTLE

OFFSET ADJUSTMENT

Diagram 12.7

MIN.

MAX.

POTENTIOMETERS

RETAINING LATCHES

SERVICE POTENTIOMETER

Rotate the service potentiometer fully anti-clockwise. Hold it in this position for about 5 seconds before rotating the service potentiometer clockwise to the mid-point or 3 o’clock position. The fan should reduce to 1200 rpm which will flash ‘12’ on the LCD display.

Check the CO

value, which should be 9.1% +0.2 -0.5. If adjustment proves necessary then proceed as follows. Adjustment of the CO

at minimum rate is very coarse so

carefully adjust the CO

with the offset adjustment to 9.1%, see

diagram 12.6. Rotate the service potentiometer fully clockwise, see

diagram12.7 and re-check the maximum rate combustion, which should be 9.1% +0.2 -0.5.

After checking combustion rotate the service potentiometer fully anti-clockwise so that the display indicates the water temperature.

Replace the cap on the test point and refit the control cover rear panel.

11481

11472

11417

31 2000225065A

Diagram 12.9

9183

DOMESTIC HOT WATER FILTER

HOUSING

SECURING CLIP

PUMP

12 Servicing

Diagram 12.8

9948

CAP

SEAL

SIPHON ADAPTER

CONDENSE TRAP

FLOAT

SCREW

12.7 Domestic Cold Water Inlet Filter

If the water flow rate through the appliance has reduced it may be necessary to clean or replace the water inlet filter.

Turn off the electrical supply to the boiler. Refer to section 12.10 and drain the domestic hot water circuit. Slide out the securing clip, which holds the filter in its housing

to the left of the pump, remove the filter to clean or renew if necessary, see diagram 12.9.

Replace the filter into its housing and replace the securing clip. Open the cold water isolating valve and test the Domestic Hot

Water circuit for soundness. Check for leaks.

12.8 Central Heating Filter

Turn off the electrical supply to the boiler. Refer to section 12.9 and drain the heating circuit of the boiler. Remove the filter retaining clip and filter clean or renew if

necessary, see diagram 12.10. Refit the filter, ensuring the correct orientation. The flat and hole

in the filter as shown in diagram 12.10. Secure with retaining clip.

Open the heating flow and return isolating valves and refill, vent and pressurise the heating circuit. See section 11.2.

Check for leaks.

2000225065A

Diagram 12.10

9184

Diagram 12.11

9302

DRAIN POINT

DRAIN VALVE

GAS SERVICE COCK

MOUNTING JIG

CENTRAL HEATING FILTER

RETAINING CLIP

HOUSING

12 Servicing

Diagram 12.12

10063

SEAL

FRONT CASING PANEL

FLAT AND HOLE

INNER CASING PANEL

9808

REAR PANEL

TORX SCREWS (3)

CONTROL BOX

RETAINING CORD

RETAINING SLOTS

Diagram 12.13

12.9 Draining of Boiler Heating Circuit

Drain down the Heating Circuit of the boiler only, by closing the heating flow and return isolating valves on the wall mounting jig, see diagram 8.1.

Attach a length of hose to the drain point and open the drain valve, see diagram 12.11.

After servicing or replacing parts, close the drain valve and remove the hose. Open the heating flow and return isolating valves and refill, vent and pressurise the heating circuit. See section 11.2.

Check for leaks.

12.10 Draining of Boiler Hot Water Circuit

Drain the Domestic Hot Water circuit by closing the cold-water isolation valve on the wall mounting jig.

Open one or more hot water taps to drain the hot water circuit. After servicing or replacing parts open the cold-water isolation

valve and slowly open a hot water tap to remove air. Close the hot water tap and check for any leaks.

12.11 Inner Casing Panel Seal Check.

Check the condition of the seal, replace as required. To replace remove the old seal, thoroughly clean the casing

sufaces. Fit the new seal, it is supplied to the correct length, see diagram 12.12.

33 2000225065A

10064

13 Fault Finding

Diagram 13.1

230V SWITCHED LIVE FROM HEATING CONTROLS.

230V SWITCHED LIVE FROM OPTIONAL FROST STAT.

REMOVE THE LINK IF FITTING VOLTAGE FREE OR 230V SYSTEM CONTROLS. IF THE LINK IS NOT REMOVED THE BOILER WILL RUN CONTINUOUSLY.

MAINS VOLTAGE HEATING CONTROLS PLUG

VOLTAGE FREE HEATING CONTROLS PLUG

CONTROLS INTERFACE

LINK

REMOVE VOLTAGE FREE LINK

2000225065A

13 Fault Finding

Diagram 13.2

10151

Before trying to operate the boiler make sure that :

• All gas supply cocks are open and that the gas supply has been purged of air.

• The heating system pressure is at least 0.7 bar.

• Check filters are clean. WARNING. Always isolate the boiler from the electrical supply

before carrying out any electrical replacement work. Always check for gas soundness after any service work.

NOTE: If the DHW control is set for pre-heat the boiler will start as soon as power is supplied to it, if there is no heating demand.

Should there be any doubt about the voltage supply to any of the components, it is possible to carry out a simple electrical test to ensure all is operational in that area.

To carry out the electrical test, gain access to the Control Box PCB, as follows:

Hinge down the control box. Remove Torx screws and unhook the rear panel. For layout of PCB, see diagram 12.1.

START

35 2000225065A

14 Replacement of Parts

14.1 General

Replacement of parts must be carried out by a competent person.

Before replacing any parts the boiler should be isolated from the mains electric supply and the gas should be turned off at the service cock on the boiler, see diagram 8.1.

Unless stated otherwise parts are replaced in the reverse order to removal.

After replacing any parts always test for gas soundness and if necessary carry out functional test of the controls.

For replacement of parts the front casing and the inner casing panel of the boiler will need to be removed. To remove undo the two screws on the underside of the front casing and lift off. Undo the two screws on the front of the inner front panel and lift off.

The side panels can be hinged sideways to aid replacement of parts.

To hinge a side panel undo and remove the three screws securing each side panel to the boiler, two at the front and one at the top.

14.2 Spark Electrode

For access, refer to section 14.1. Remove the spark plug lead, earth lead and two securing

screws. Withdraw the spark electrode carefully from the combustion chamber, see diagram 12.2.

14.3 Igniter Unit

For access, refer to section 14.1. Remove ignition lead and electrical connections then remove

igniter unit by removing two securing screws, see diagram 14.1.

14.4 Ignition Lead

For access, refer to section 14.1. Refer to diagram 12.5. Pull the spark plug style connector off the spark electrode and

the spade connector connected to the igniter unit, see diagram 14.1.

14.5 DC Fan supply

For access, refer to section 14.1. Refer to diagram 14.2. Unplug white plastic plug from the DC fan supply. Drop down control panel to the service position, see diagram

12.13. Undo the three screws securing rear cover and lift off. Unplug DC fan supply lead from main PCB, see diagram 14.3. Release cable grip located on boiler case. Remove DC fan supply cable from retaining clip located to the

right of cable grip. Undo the two screws securing DC fan supply. Hinge right hand side panel, refer to relevant part of section

14.1. Remove DC fan supply and lead.

Diagram 14.3

MAIN PCB

Diagram 14.2

DC FAN SUPPLY

11420

PLUG

CABLE GRIP

SECURING SCREW (2)

Diagram 14.1

IGNITER UNIT

IGNITION LEAD

ELECTRICAL CONNECTIONS

SECURING SCREWS (2)

SPADE CONNECTOR

COVER SECURING SCREWS

DC FAN SUPPLY CONNECTION

FUSE

RETAINING CLIPS

11491

11492

2000225065A

14 Replacement of Parts

14.6 Gas Control Valve

For access, refer to section 14.1. Remove the electrical plug from the gas control valve, see

diagram 14.4. Refer to section 12.3 for removal of the fan, gas valve and

burner assembly. Before removing the gas valve note its position on the fan. Remove the three securing screws, which fix the gas valve and

plastic swirl plate to the venturi on the fan, see diagram 14.5. Remove the gas valve. When re-fitting the gas valve take care as it can be fitted more

than one way. After re-fitting check the combustion CO

and adjusted if

necessary, see section 12.6. After assembly test for gas soundness and purge in accordance

with the current issue of BS6891or in IE, the current edition of I.S.813 "Domestic Gas Installations".

14.7 Fan

For access, refer to section 14.1. Refer to section 12.3 for removal of the fan, gas valve and

burner assembly. Remove the gas control valve as described in the relevant parts

of section 14.6. Remove the venturi plate secured with three screws, see

diagram 14.5. Remove the two screws securing the fan to the gas manifold,

see diagram 14.6, check the gasket and replace if necessary. NOTE : The 30 fan is secured through an extension piece with

two securing screws, check and replace any seals or gaskets if necessary.

14.8 Burner

For access, refer to section 14.1. Refer to section 12.3 for removal of the fan, gas valve and

burner assembly. Remove the four screws that secure the burner, see diagram

14.7. NOTE: THE BURNER WILL REQUIRE A NEW GASKET

WHEN REFITTED.

Diagram 14.6

Diagram 14.5

SECURING SCREW (2)

Diagram 14.4

11481

ELECTRICAL PLUG

GAS CONTROL VALVE

PRESSURE TEST POINT

SECURING SCREW (3)

Diagram 14.7

SECURING SCREW (4)

VENTURI PLATE

FAN

GAS MANIFOLD

BURNER

INSULATION

11486

11485

11487

24cxi Illustrated

37 2000225065A

14 Replacement of Parts

14.9 Front Insulation

For access, refer to section 14.1. Refer to section 12.3 for removal of the fan, gas valve and burner

assembly. Remove burner as per section 14.8. Remove spark electrode, see section 14.2. NOTE: THE BURNER WILL REQUIRE A NEW GASKET WHEN

REFITTED.

14.10 Rear Insulation

For access, refer to section 14.1. Refer to section 12.3 for removal of the fan, gas valve and burner

assembly. Remove securing screw and washer in the centre of the insulation

and withdraw insulation, see diagram 14.8.

14.11 Viewing Window

For access, refer to section 14.1. Refer to diagram 14.9. Remove circlip. Remove steel washer. Remove glass. Remove fibre washer. Replace in reverse order.

14.12 Expansion Vessel

For access, refer to section 14.1. Refer to section 12.9 and drain the boiler heating circuit. Undo the coupling at the base of the vessel, see diagram 14.10. While holding the vessel remove the securing bolt on the top

panel of the boiler. Remove upper support bracket. Lift the vessel up, draw bottom out to the left, lower and remove. Fit the replacement unit. Fit a new gasket between the expansion vessel and coupling. Refill, vent and pressurise the boiler. Check for leaks.

HEAT EXCHANGER

Diagram 14.8

SECURING SCREW

WASHER

REAR INSULATION

Diagram 14.9

CIRCLIP

GLASS

STEEL WASHER

FIBRE WASHER

Diagram 14.10

SECURING BOLT

COUPLING

UPPER SUPPORT BRACKET

EXPANSION VESSEL

11412

11413

11488

11489

2000225065A

14 Replacement of Parts

14.13 Heat Exchanger

For access, refer to section 14.1. Refer to section 12.3 for removal of the fan, gas valve and

burner assembly. Drain the boiler heating circuit, see section 12.9. Drain the boiler hot water circuit, see section 12.10. Remove the clip securing the clear condense pipe to heat

exchanger. Pull to remove the clear condense pipe out of the bottom of the

heat exchanger. Undo the two nuts of the flow and return pipes from the heat

exchanger. Move the pipes away from the heat exchanger. Loosen the three heat exchanger securing screws and clamps

(two at the top and one at the bottom) to remove the heat exchanger, see diagram 14.11.

CAUTION: There will be water in the heat exchanger. Remove condense pipe connector from bottom of heat

exchanger. Carefully ease heat exchanger out.

14.14 Flue Hood

For access, refer to section 14.1. Remove heat exchanger as per section 14.13. Remove the two securing screws and pull the hood down and

away from the flue hood bracket and flue elbow, see diagram

14.12.

14.15 Diverter Switch

For access, refer to section 14.1. Refer to diagram 14.13. Remove the electrical plug. Remove the retaining clip. Ease the diverter switch from its housing and remove.

14.16 Pump (head only)

For access, refer to section 14.1. Refer to section 12.9 and drain the boiler heating circuit. Refer to diagram 14.14. Remove the four cap head screws. Carefully remove the pump head together with cable. Do not

strain cable. Support the pump head, unscrew cable cover at the side of

pump head and take off. Disconnect wiring from pump head. Reconnect wiring to new pump head and fit cover. Fit the new pump head with ‘O’ ring. Refill, vent and pressurise the boiler. Check for leaks.

Diagram 14.11

FLOW AND RETURN PIPE NUTS

SECURING SCREWS AND CLAMPS

Diagram 14.12

FLUE HOOD BRACKET

SECURING SCREWS

10066

DIVERTER SWITCH

DIVERTER VALVE

Diagram 14.13

ELECTRICAL PLUG)

RETAINING CLIP (NOTE ORIENTATION)

11602

11490

FLUE HOOD

39 2000225065A

14 Replacement of Parts

Diagram 14.14

Diagram 14.15

PUMP HEAD

CAP HEAD SCREW (4)

SAFETY DISCHARGE VALVE

Diagram 14.16

14.17 Safety Discharge Valve

For access, refer to section 14.1. Refer to section 12.9 and drain the boiler heating circuit. Refer to diagram 14.15. Undo the safety discharge valve union and remove from the

pipework. Remove the securing clip and withdraw the safety discharge

valve. Fit new 'O' ring. Refill, vent and pressurise the boiler. Check for leaks.

14.18 Domestic Hot Water Thermistor

For access, refer to section 14.1. Refer to section 12.10 and drain the boiler domestic hot water

circuit. Refer to diagram 14.16. Disconnect the domestic hot water thermistor electrical

connections Remove retaining clip. Withdraw domestic hot water thermistor from its housing. Note: When reconnecting electrical connections, polarity is not

important. Fit new 'O' ring. Carry out a functional test of the controls.

14.19 Heating Flow Thermistor

For access, refer to section 14.1. Refer to diagram 14.17. Remove the electrical connections from the thermistor. Remove the retaining clip from the flow pipe. Remove the thermistor from the retaining clip. Note: When reconnecting the polarity of the wiring to thermistors

is unimportant.

14.20 Heating Return Thermistor

is unimportant.

14.21 Overheat Thermostat

For access, refer to section 14.1. Refer to diagram 14.17. Remove the electrical connections from the overheat thermostat. Remove the retaining clip from the flow pipe. Remove the overheat thermostat from the retaining clip. NOTE. When fitting new thermostat, please ensure that it is

located correctly onto the flat area of the pipe and the retaining clip is secure.

CABLE COVER

DOMESTIC HOT WATER THERMISTOR

RETAINING CLIP

11694

11495

11496

2000225065A

14 Replacement of Parts

14.22 Automatic Air Vent

For access, refer to section 14.1. Refer to section 12.9 and drain the boiler heating circuit. Refer to diagram 14.18. Unscrew the automatic air vent. Fit the new automatic air vent and ‘O’ring ensuring the vent cap

is left loose. Refill, vent and pressurise the boiler. Check for leaks.

14.23 Flow Sensor

For access, refer to section 14.1. Refer to section 12.10 and drain the boiler hot water circuit. Refer to diagram 14.19. Remove the clip securing the filling loop tube to the domestic

water filter housing, see diagram 14.22. Pull the tube forward to disengage it before rotating it down and

out of the way. Undo the brass securing nut above the cold water inlet valve. Remove the securing clip between the domestic water filter

housing and the flow sensor, see diagram 14.19. Disengage the domestic water filter housing by lifting it up and

out. Remove the electrical connection to the flow sensor. Remove the securing clip between the flow sensor and the

hydroblock. Remove flow sensor. Fit new ‘O’ rings. After replacing the flow sensor, open the cold-water isolation

valve and slowly open a hot water tap to remove air. Close the hot water tap and check for any leaks.

14.24 Low Water Pressure Sensor

For access, refer to section 14.1. Refer to section 12.9 and drain the boiler heating circuit. Refer to diagram 14.20. Disconnect the electrical lead by pushing up retaining tab to

withdraw the lead plug. Remove the retaining clip to remove the low water pressure

sensor. Fit new 'O' ring. Fit the new low water pressure sensor. Refill vent and pressurise

the boiler. Check for leaks.

14.25 Bypass Tube

For access, refer to section 14.1. Refer to section 12.9 and drain the boiler heating circuit. Refer to diagram 14.21. Remove the retaining clips to remove the bypass tube. Fit new ‘O’ rings. Replace the bypass tube, refill, vent and pressurise the boiler. Check for leaks.

Diagram 14.18

AUTOMATIC AIR VENT

14.26 Filling Loop Tube

For access, refer to section 14.1. Refer to section 12.10 and drain the boiler hot water circuit. Refer to diagram 14.22. Remove the retaining clips to remove the filling loop tube. Fit new ‘O’ rings. After replacing the filling loop tube open the cold-water isolation

valve and slowly open a hot water tap to remove air. Close the hot water tap and check for any leaks.

Diagram 14.17

RETURN PIPE

FLOW PIPE

RETURN THERMISTOR

OVERHEAT THERMOSTAT

FLOW THERMISTOR

11498

11503

41 2000225065A

14.27 Filling Loop Valve.

For access, refer to section 14.1. Refer to section 12.10 and drain the boiler hot water circuit. Refer to diagram 14.22. Remove the clip securing the filling loop valve to the domestic

water filter housing. Disengage by pulling forward. Remove the clip securing the filling loop to the filling loop valve. Remove the filling loop valve from the filling loop. Fit new ‘O’ rings. After replacing the filling loop valve open the cold water isolation

valve and slowly open a hot water tap to remove air. Close the hot water tap and check for any leaks.

14.28 Automatic Bypass Valve

For access, refer to section 14.1. Refer to section 12.9 and drain the boiler heating circuit. Refer to diagram 14.21. Remove the retaining clip to remove the bypass valve. Fit new ‘O’ rings. Replace the bypass valve, refill, vent and pressurise the boiler. Adjust the bypass as described in commissioning, see section

11.6. Check for leaks.

14.29 Reduced Pressure Zone Valve

For access, refer to section 14.1. Refer to diagram 14.23. Refer to section 14.26 to remove the filling loop Remove the retaining clip to remove the reduced pressure zone

valve. Fit new ‘O’ rings. Replace the reduced pressure zone valve, refill, vent and

pressurise the boiler. Check for leaks.

14.30 Domestic Cold Water Inlet Filter

For access, refer to section 14.1. Refer to section 12.7. Fit new ‘O’ rings.

14 Replacement of Parts

Diagram 14.19

FLOW SENSOR

Diagram 14.20

LOW WATER PRESSURE SENSOR

Diagram 14.21

BYPASS TUBE

ELECTRICAL LEAD AND PLUG

Diagram 14.22

FILLING LOOP TUBE

FILLING LOOP VALVE

RETAINING CLIP

RETAINING CLIPS

AUTOMATIC BYPASS VALVE

RETAINING CLIP

11474

11476

11494

11497

2000225065A

14.31 Central Heating Filter

Refer to section 12.8. Fit new ‘O’ rings.

14.32 Heating Circuit Drain Point

Refer to section 12.9 to drain the boiler heating circuit. Refer to diagram 14.24. Remove the retaining clip to remove the drain point. Fit new ‘O’ rings. Replace the drain point, refill, vent and pressurise the boiler. Check for leaks.

14.33 Inner Casing Panel Seal

For access, refer to section 14.1. Refer to diagram 14.25. Remove the inner casing panel. To replace remove the old seal, thoroughly clean the casing

surfaces. Fit the new seal, it is supplied to the correct length. Refit the inner casing panel. NOTE: Ensure the seal is fitted correctly giving an airtight joint.

14.34 Condense Drain

For access, refer to section 14.1. Refer to section 12.5.

14.35 Plate-to-Plate Heat Exchanger

For access, refer to section 14.1. Refer to section 12.9 to drain the boiler heating circuit. Refer to section 12.10 and drain the boiler hot water circuit. Refer to diagram 14.26. Remove the gas supply pipe from the gas cock and the gas

valve, refer to relevant parts of section 12.3. Undo the central heating flow pipe connection into the left hand

hydroblock, see diagram 14.26. Undo the nut connecting flow pipe to heat exchanger.

Lift it up to remove it from the hydroblock with the washer and rotate it forward and out of the way.

Using a TORX screwdriver remove the two screws securing the plate-to-plate heat exchanger to the hydroblock.

Remove the plate-to-plate heat exchanger by lifting it up and over the top of the left hand hydroblock.

When replacing the plate-to-plate heat exchanger ensure that the four rubber sealing washers are fitted into the hydroblock.

NOTE: The plate-to-plate heat exchanger only fits one way round, 'TOP' is marked on the plate.

Refill, vent and pressurise the boiler. Open the cold-water isolation valve and slowly open a hot water

tap to remove air. Close the hot water tap and check for any leaks. Open the heating circuit isolation valves, re-pressurise the

system as necessary.

14 Replacement of Parts

Diagram 14.23

REDUCED PRESSURE ZONE VALVE

Diagram 14.25

10063

SEAL

FRONT CASING PANEL

INNER CASING PANEL

Diagram 14.24

DRAIN POINT

RETAINING CLIP

11477

11501

43 2000225065A

14.36 Hydroblock Assembly Left-Hand

Refer to section 12.9 to drain the boiler heating circuit. Refer to section 12.10 and drain the boiler hot water circuit. Refer to diagram 14.26. Undo the connector on the bottom of the flow pipe from the

hydroblock. Undo the nut connecting flow pipe to heat exchanger. Lift the flow pipe up out of the way. Remove the filling loop tube, refer to section14.26. Remove the reduced pressure zone valve, refer to section

14.29. Remove the bypass tube, refer to section 14.25. Undo the safety discharge valve union and remove the pipework. Remove the securing clip and withdraw the safety discharge

valve, refer to section 14.17. Remove securing clips 1 and 2 below hydroblock, see diagram

14.26. Undo three securing screws on the underside of the left-hand

hydroblock. Remove the diverter switch as described in section 14.15.

14 Replacement of Parts

Diagram 14.26

Remove left hand hydroblock from plate-to-plate heat exchanger using a TORX screwdriver to remove the securing screw, see diagram 14.26.

Lift out the left hand hydroblock. Remove the remaining components for refitting into the

replacement left hand hydroblock. Refill, vent and pressurise the boiler. Open the cold water isolation valve and slowly open a hot water

tap to remove air. Close the hot water tap. Check for any leaks.

14.37 Diverter Valve

For access, refer to section 14.1. Refer to section 12.9 and drain the boiler heating circuit. Refer to section 12.10 and drain the boiler hot water circuit. Remove the diverter switch as described in 14.15. Refer to section 14.36 to remove the left hand hydroblock. Unscrew and remove both halves of the diverter valve from the

left hand and right hand sides of the hydroblock, see diagram

14.27. When replacing the two halves of the diverter valve it is

important to ensure the spindle is located correctly. This can be observed with the left hand hydroblock removed.

SAFETY DISCHARGE VALVE

SECURING CLIP 1

FLOW PIPE CONNECTOR

PLATE TO PLATE HEAT EXCHANGER SECURING SCREW

SECURING CLIP 2

SECURING CLIP 3

RH HYDROBLOCK

LH HYDROBLOCK

OUTLET CONNECTOR

PLATE TO PLATE HEAT EXCHANGER SECURING SCREW

SECURING CLIP 4

11499

11478

11500

2000225065A

14 Replacement of Parts

14.38 Hydroblock Assembly Right-Hand

For access, refer to section 14.1. Refer to section 12.9 to drain the boiler heating circuit. Refer to section 12.10 and drain the boiler hot water circuit. Refer to diagram 14.26. Undo the connector on the bottom of the return pipe from the

hydroblock. Undo the nut connecting return pipe to heat exchanger. Lift the return pipe up out of the way. Undo the coupling at the base of the expansion vessel, see

diagram 14.10. Remove the clip holding the expansion vessel coupling into the

top of the right hand hydroblock. Move the coupling out of the way. Remove pump head, refer to section 14.16. Note: It is not necessary to disconnect the electrical lead but put

pump head in a convenient place where it will not strain the lead. Remove the filling loop tube, refer to section 14.26. Remove the bypass tube, refer to section 14.25. Remove the electrical connections to the flow sensor and the

low water pressure sensor, refer to sections 14.23 and 14.24. Remove the water connection clips 3 and 4 below the hydroblock,

see diagram 14.26. Remove the central heating filter, refer to section 12.8. Remove the retaining clip to remove the drain point, refer to

section 14.32. Undo two securing screws on underside of the right hand

hydroblock. Remove right hand hydroblock from plate-to-plate heat

exchanger using a TORX screwdriver to remove the securing screw, see diagram 14.26.

Lift out the right hand hydroblock. Remove the remaining components for refitting into the

replacement right hand hydroblock. Refill, vent and pressurise the boiler. Open the cold-water isolation valve and slowly open a hot water

tap to remove air. Close the hot water tap. Check for leaks.

14.39 Access to Switches, User Interface and Timer

For access, refer to section 14.1. Release the front of the fascia by carefully prising up the two

retaining latches, see diagram 14.28. Do not allow the front of the fascia to swing down and be loosely

held by the electrical connections to the mains/reset switch, user interface and clock. Either remove the connections or support the fascia.

14.40 Clock/Timer (if fitted)

Refer to section 14.39 for access. Remove electrical plug. Undo two securing screws and withdraw clock/timer.

14.41 Mains/Reset Switch

Refer to section 14.39 for access. Remove the switch retaining screw. Remove switch from housing, see diagram 14.29. Remove electrical leads.

Diagram 14.27

Diagram 14.28

RETAINING LATCHES

DIVERTER VALVE

L.H. HYDROBLOCK

10101

11472

45 2000225065A

Diagram 14.29

14 Replacement of Parts

Diagram 14.30

14.42 Mains/Reset Knob

Refer to section 14.39 for access. Remove actuator by springing back retaining clips, see diagram

14.29. Spring back knob retaining clips and push knob out from the

back.

14.43 User Interface/Display Unit PCB

Refer to section 14.39 for access. Remove electrical plug. Remove the three securing screws. Withdraw the board, see diagram 14.31. When replacing the board refer to instructions supplied with

replacement PCB on setting it up.

14.44 Control Box PCB

For access, refer to section 14.1. Hinge down the control box. Remove TORX screws and unhook the rear panel. Remove the electrical connections to the PCB. Prise back the two PCB retaining clips and withdraw the PCB,

see diagram 14.30. When refitting the rear panel ensure the leads are not trapped,

refer to diagram 14.3.

14.45 Control Box

For access, refer to section 14.44. Remove relevant plugs and connectors, refer to wiring diagram

13.1. Withdraw grommets and leads so they are hanging loose. Unthread the retaining cord and remove the control box by

drawing it outwards away from its retaining slots, see diagram

14.30.

14.46 Fuses PCB - Control Box

For access, refer to section 14.44. The fuse is located at bottom right hand side of the PCB, see

diagram 14.3.

9808

REAR PANEL

TORX SCREWS (3)

CONTROL BOX

PCB RETAINING CLIPS

MAINS/RESET KNOB

MAINS/RESET SWITCH

KNOB RETAINING CLIPS

RETAINING CORD

RETAINING SLOTS

Diagram 14.31

DISPLAY UNIT PCB

SECURING SCREWS

11416

11417

11420

2000225065A

Key No. Part No. Description GC Part No.

1 801721 DC Fan Supply * 2 801724 Overheat Cutoff * 3 801911 Pressure Sensor * 4 801831 Plate to Plate Heat Exchanger * 5 801192 Diverter switch * 6 801637 Electrode * 7 801904 Safety Discharge Valve * 8 801898 Automatic Air Vent *

9 801897 Central Heating Filter * 10 801722 Heating flow thermistor /Heating return thermistor * 11 801649 24/30/38cxi Gas control valve * 13 * Mains/Reset Switch * 14 801910 Flow Sensor * 15 801655 Igniter Unit * 16 801909 By-pass * 17 801923 230V Controls Interface * 18 801719 Control Box P.C.B. * 19 801380 Pump (head only) * 20 801645 Fan * 21 801727 Display Board * 22 801632 24cxi Burner * 22 ******** 30cxi Burner * 22 ******** 38cxi Burner *

When ordering spare parts, contact Heatcall (Glow-worm's own service organisation) using the telephone number on the inside front cover of this booklet.

15 Spare Parts

14 Replacement of Parts

PCB - DC Fan Supply

For access, refer to section 14.1. Refer to diagram 14.2 and wiring diagram 13.1. Undo the two screws securing the front cover of the DC Fan

Supply and remove. The fuse is located near the centre of the PCB.

14.47 230V Controls Interface

For access, refer to section 14.39. Disconnect the electrical connection from the 230V controls

board and the electrical connection from the control box PCB. Remove the 230V controls interface retaining screw. Remove the 230V controls interface board, see diagram 14.32.

Diagram 14.32

230V CONTROLS INTERFACE BOARD

DISPLAY UNIT PCB

RETAINING SCREW

11419

Please quote the name of the appliance and serial number, to be found on the data label, see diagram 14.30.

If ordering from British Gas also quote the G.C. number of the part.

47 2000225065A

15 Spare Parts

9307

Diagram 15.1

2000225065A

Because of our constant endeavour for improvement, details may vary slightly from those shown in these instructions.

Glow-worm 24cxi, 30cxi, 38cxi Instructions For Use Installation And Servicing

Specifications and Main Features

Frequently Asked Questions

User Manual