ideal Mini HE C24 User guide

Download

Page 1

installation and servicing

mini HE

Your Ideal installation and servicing guide

For details of document amendments, refer to page 3

C24,C28

For users guide see reverse of book

When replacing any part of this appliance, use only spare parts that you can be assured conform to safety and performance specification that we require. Do not use reconditioned or copy parts that have not been clearly authorised by Ideal Boilers

17962.1138.1 0406 64A4 GB

*1796211381*

For the very latest copy of literature for specification purposes please visit our website www.idealboilers.com where you will be able to download the relevant information in pdf format.

Page 2

mini HE --- Installation & Servicing

Page 3

DOCUMENT AMENDMENTS

Relevant Installation changes implemented in this book from Mod Level.............4905 to 0406

F Pages 33 and 37

Amendment to the illustration of the air pressure switch connection

Caradon Ideal Limited reserve the right to vary specification without notice

mini HE --- Installation & Servicing

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GENERAL

Table 1 --- Boiler Data

mini HE C24 mini HE C28

Gas supply type & connection II

Inlet / Outlet connection --- Domestic Hot Water 15 mm copper

Flow & return connection --- Central Heating 22 mm copper

Flue terminal diameter mm (in.) 100 (4)

Max working pressure (sealed system) bar (lb/in2) 3.0 (43.5)

Max DHW water inlet pressure bar (lb/in2) 10.0 (145.0)

Min DHW water inlet pressure bar (lb/in2) 0.3 (4.4)

Electrical supply 230 Vac 50 Hz

Max power consumption W 140 150

External fuse rating 3 A

Internal fuse rating T 2A

Water content --- CH litre (gal.) 2.1 (0.46) 2.2 (0.48)

Water content --- DHW litre (gal.) 0.2 (0.044)

Dry weight kg (lb.) 42.5 (93.7) 44.5 (98.1)

Size: Height / Width / Depth mm (in.) 803 (31 5/8”) / 400 (15 3/4”) / 345 (13 9/16”)

Lift weight kg (lb.) 37.5 (82.7) 39.5 (87.1)

Table 2 --- Performance Data --- Central Heating

mini HE C24 mini HE C28

Max Min Max Min

Burner pressure (Hot) G20

G31

Input based on nett CV kW (btu/h) 25.0 (85 295) 11.0 (37 530) 29.0 (98 942) 13.0 (44 353)

Input based on gross CV kW (btu/h) 27.7 (94 516) 12.2 (41 628) 32.2 (109 871) 14.4 (49 135)

Output Non Condensing G20

G31

Output Condensing G20

G31

Gas consumption (Hot) G20

G31

Seasonal efficiency* G20

G31

NOx classification Class 2

mbar (in.w.g.) 10.8 (4.3)

kW (btu/h) 24.6 (83 973)

kW (btu/h) 26.6 (90 754)

l/s (ft3/h) l/s

(SEDBUK) % Band B 87.7

35.5 (14.2)

23.7 (80 894)

26.6 (90 754)

0.74 (93.6)

0.30

Band B 86.9

*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 have been certified by a notified body.

Table 3 --- Performance Data --- Domestic Hot Water

mini HE C24 mini HE C28

Burner pressure (Hot) G20

G31

Input based on nett CV kW (btu/h) 25.0 (85 295) 29.0 (98 942)

Input based on gross CV kW (btu/h) 27.7 (94 516) 32.2 (109 871)

Output Non Condensing G20

G31

Output Condensing G20

G31

Gas consumption (Hot) G20

G31

Flow 35 ° C temp. rise l/m (gpm) 10.1 (2.2) 11.7 (2.6)

Domestic hot water specific rate l/m (gpm) 11.9 (2.6) 13.9 (3.1)

Note: the gas consumption is calculated using a calorific

mbar (in.w.g.) 10.8 (4.3)

kW (btu/h) 24.6 (83 973)

kW (btu/h) 26.6 (90 754)

l/s (ft3/h) l/s

35.5 (14.2)

23.7 (80 894)

26.6 (90 754)

0.74 (93.6)

Key to Symbols:

value of 38.7 MJ/m3(1038 Btu/ft3) gross or 34.9 MJ/m3(935 Btu/ft3) nett.

To obtain the gas consumption at different calorific value: ---

a. FOR L/S --- divide the gross heat input (kW) by the gross C.V. of the gas (MJ/m3)

b. FOR FT3/H --- divide the gross heat input (Btu/h) by the gross C.V. of the gas (Btu/ft3)

IE = Ireland, GB = United Kingdom (Countries of destination) PMS = Maximum operating pressure of water C12C32C42= a room sealed appliance designed for connection via concentric ducts to a horizontal or vertical terminal or twin flue system.

H or 3rd family gas group 3P

G20 20mbar, G31 37mbar, 22 mm copper

2H3P

1.5 (0.6)

7.7 (3.1)

10.2 (34 936)

11.1 (37 871)

10.8 (36 997)

0.32 (40.9)

0.13

Maximum

0.30

= appliance designed for use on 2nd family gas group

2H3P

10.0 (4.0)

36.0 (14.4)

28.3 (96 488)

27.4 (93 599)

30.7 (104 602)

0.85 (108.4)

0.34

Band B 87.5 Band B 87.0

28.3 (96 488)

27.4 (93 599)

30.7 (104 602)

0.85 (108.4)

1.6 (0.6)

7.7 (3.1)

12.1 (41 284)

13.2 (44 965)

12.9 (44 016)

0.35 (45.2)

10.0 (4.0)

36.0 (14.4)

0.34

0.14

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

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

mini HE --- Installation & Servicing

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GENERAL

mini HE

Boiler size G.C. appliance No. PI No.

(Benchmark No.)

mini HE C24 47 ---348 ---38 0694BP0384 mini HE C28 47 ---348 ---39 0694BP0384

Destination countries: GB, IE

CONTENTS

Air supply 9

Benchmark Commissioning Checklist 58

Boiler clearances 6

Boiler exploded view 14

Electrical connections 20

Electrical supply 10

Fault finding 48

Flow wiring diagram 24

Flue fitting 16

Gas conversion 29

Gas safety regulations 7

Gas supply 8

Installation 15

Mandatory requirements 7

Replacement of components 34

Safe handling 7

Servicing 30

Short list of parts 55

Thermostatic radiator valves 12

Water connections 19

Water treatment 9

Wiring diagrams 22

For GB, to comply with Building Regulations Part L1 (Part J in Scotland) the boiler should be fitted in accordance with the manufacturer’s instructions. Self--- certification that the boiler has been installed to comply with Building Regulations can be demonstrated by completing and signing the Benchmark Commissioning Checklist.

BENCHMARK COMMISSIONING CHECKLIST DETAILS

Boiler Page

Make and model 5

Appliance serial no. on data badge 14

SEDBUK No. % 4

Controls

Time and temperature control to heating 26

Time and temperature control to hot water 26

Heating zone valves 26

TRV’s 12

Auto bypass 12

Boiler interlock 12

For all boilers

Flushing to BS.7593 9

Inhibitor 9

Central heating mode

Heat input to be calculated

Boiler Page

Burner operating pressure measure and record Central heating flow temp. measure and record Central heating return temp. measure and record

For combination boilers only

Scale reducer 12 Hot water mode Heat input to be calculated Max. operating burner pressure measure and record Max. operating water pressure measure and record Cold water inlet temp measure and record Hot water outlet temp. measure and record Water flow rate at max. setting measure and record

For condensing boilers only

Condensate drain 20 For all boilers: complete, sign & hand over to customer For assistance see Technical Helpline on the back page

NOTE TO THE INSTALLER: COMPLETE

THE BENCHMARK COMMISSIONING

CHECKLIST AND LEAVE THESE

INSTRUCTIONS WITH APPLIANCE

mini HE --- Installation & Servicing

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GENERAL

1 BOILER WATER CONNECTION

400

803

700

257

Wall

mounting

Plate

Condensate

drain

connection

area

Pipe size O.D. mm

CH flow 22

CH return 22

Gas inlet 22

DHW cold inlet 15

DHW hot outlet 15

83 (3 1/4”)

52 (2”)

65 (2 9/16”)

CH flow

DHW hot outlet *

65 (2 9/16”)

64 (2 1/2”)

Gas inlet

CH return

DHW cold inlet *

2 BOILER CLEARANCES

All dimensions in mm (in.)

The following minimum clearances must be maintained for operation and servicing. Additional space will be required for installation, depending upon site conditions.

200 (7 7/8”)

25 (1”) 50 (2”)

Side and Rear Flue

a. Provided that the flue hole is cut accurately, e.g. with a core

drill, the flue can be installed from inside the building where wall thickness does not exceed 600 mm (24”).

Where the space into which the boiler is going to be installed is less than the length of flue required the flue must be fitted from the outside.

installation from inside ONLY

b. If a core boring tool is to be used inside the building the

space in which the boiler is to be installed must be at least wide enough to accommodate the tool.

273 (10 3/4”) 127 (5”)

190 (7 1/2”)

200 (7 7/8”)

Bottom clearance

The bottom clearance, after installation, can be reduced to 20mm. However, 200mm must be available for servicing.

Front clearance

The minimum front clearance when built into a cupboard is 50mm (2”) from the cupboard door. However 450mm (17 3/4”) overall clearance is still required, with the cupboard door open, to allow for servicing.

95 ()

mini HE --- Installation & Servicing

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GENERAL

INTRODUCTION

mini HE C24 and mini HE C28 are wall mounted, low water

content, balanced flue, condensing combination gas boilers.

Central heating (CH) output and domestic hot water (DHW) output are both fully modulating:

--- between 10.2 (34 936) and 24.6* (83 973) kW (btu/h) for

model mini HE C24;

--- between 12.1 (41 284) and 28.3* (96 488) kW (btu/h) for

model mini HE C28.

* ouputs with G31 (propane) feeding are sligthly different. See section Boiler Data at page 4 for detailed figures.

Due to the high efficiency of the boiler a plume of water vapour will form at the terminal during operation.

The boilers are suitable for connection to fully pumped, pressurised sealed water systems ONLY.

A system bypass is not required when TRV’ s are fitted to all radiators (see Frame 5). The boiler incorporates an automatic bypass.

A circulating pump, pressure gauge, safety valve and heating expansion vessel are provided.

The CH flow temperature is controlled by a thermistor. In DHW mode the boiler modulates to sustain a nominal adjustable water flow temperature of 55 ° C.

The boiler casing is of white painted mild steel with a drop---down controls access door.

The boiler temperature control is located behind the control panel door.

The main heat exchanger is made of copper.

The condensing heat exchanger (recuperator) and the DHW heat exchanger are stainless steel.

The system pipework must include drain cocks in appropriate places. Pipework may be taken downwards.

For upwards pipework installation an additional frame (optional) must be used (see frame 18).

OPTIONAL EXTRA KITS

Programmer Kit fits neatly within the casing. Separate fitting instructions are included with the kit. Note. If using an alternative programmer read Frame 25 first.

Horizontal Concentric Extension Ducts

Up to 2,7 m (8’ 10”) for all models.

Other available kits are listed in frame 9.

SAFE HANDLING

This boiler may require 2 or more operatives to move it to its installation site, remove it from its packaging base and during movement into its installation location. Maneuvering the boiler may include the use of a sack truck and involve lifting, pushing and pulling.

Caution should be exercised during these operations.

Operatives should be knowledgeable in handling techniques when performing these tasks and the following precautions should be considered:

F Grip the boiler at the base. F Be physically capable. F Use PPE as appropriate, e.g. gloves, safety footwear.

During all maneuvers and handling actions, every attempt should be made to ensure the following unless unavoidable and/or the weight is light.

F Keep back straight. F Avoid twisting at the waist.

mini HE --- Installation & Servicing

F Avoid upper body/top heavy bending. F Always grip with the palm of the hand. F Use designated hand holds. F Keep load as dose to the body as possible. F Always use assistance if required.

DHW OPERATION

With no call for CH the boiler fires only when DHW is drawn off. When there is a call for CH, the heating system is supplied at the selected temperature until DHW is drawn off. The output is then directed by the diverter valve to heat the secondary heat exchanger and supply a maximum draw--- off of:

mini HE C24. 10.1 (2.2) l/min (gpm) at 35 degree rise.

mini HE C28 11.7 (2.6) l/min (gpm) at 35 degree rise.

The nominal DHW temperature is 55 ° C, but water drawn off when the boiler has been on for central heating may be hotter than this, for a short period of time.

GAS SAFETY

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

The appliance is suitable only for installation in GB and IE and should be installed in accordance with the rules in force. In GB, the installation must be carried out by a CORGI Registered Installer. It must be carried out in accordance with the relevant requirements of the:

F Gas Safety (Installation and Use) Regulations F The appropriate Building Regulations either The Building

Regulations, The Building Regulations (Scotland), Building Regulations (Northern Ireland).

F The Water Fittings Regulations or Water byelaws in

Scotland.

F 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.

Detailed recommendations are contained in the following British Standard Codes of Practice:

BS 5440:1 Flues (for gas appliances of rated input not

exceeding 70 kW).

BS 5440:2 Ventilation (for gas appliances of rated input

not exceeding 70 kW).

BS. 5449 Forced circulation hot water systems.

BS. 5546 Installation of gas hot water supplies for

domestic purposes (2nd Family Gases)

BS 6700 Design, installation testing and maintenance of

services supplying hot water for domestic use.

BS. 6798 Installation of gas fired hot water boilers of

rated input not exceeding 70 kW.

BS. 6891 Low pressure installation pipes.

Health & Safety Document No. 635.

The Electricity at Work Regulations, 1989.

The manufacturers notes must NOT be taken, in any way, as overriding statutory obligations.

IMPORTANT These appliances are CE certificated for safety and performance. It is, therefore, important that no external control devices, e.g. flue dampers, economisers etc., are directly connected to these appliances unless covered by

Page 8

GENERAL

these Installation and Servicing Instructions or as otherwise recommended by Caradon Ideal Ltd. in writing. If in doubt please enquire.

Any direct connection of a control device not approved by Caradon Ideal Ltd. could invalidate the certification and the normal appliance warranty. It could also infringe the Gas Safety Regulations and the above regulations.

SAFE HANDLING OF SUBSTANCES

Care should be taken when handling the boiler insulation panels, which can cause irritation to the skin. No asbestos, mercury or CFCs are included in any part of the boiler in its manufacture.

LOCATION OF BOILER AND FLUE OUTLET

The boiler must be installed on a flat and vertical wall, capable of adequately supporting the weight of the boiler and any ancillary equipment.

The boiler may be fitted on a combustible wall and insulation between the wall and the boiler is not necessary, unless required by the local authority.

The boiler must not be fitted outside.

Timber Framed Buildings

If the boiler is to be fitted in a timber framed building it should be fitted in accordance with the Institute of Gas Engineers document IGE/UP/7, 1998.

Bathroom Installations

The boiler may be installed in any room or internal space, although particular attention is drawn to the requirements of the current I.E.E. (BS.7671) Wiring Regulations and, in Scotland, the electrical provisions of the building regulations applicable in Scotland with respect to the installation of the boiler in a room or internal space containing a bath or shower.

For Ireland reference should be made to the current ETCI rules for electrical installations and I.S.813:2002

Where a room sealed appliance is installed in a room containing a bath or shower then the appliance and any electrical switch or appliance control utilising mains electricity should be so situated that it cannot be touched by a person using the bath or shower.

Note. It is not permissible to install a mains socket in a bathroom.

Where installation will be in an unusual location, special procedures may be necessary and BS 6798 gives detailed guidance on this aspect.

Compartment Installations

A compartment used to enclose the boiler should be designed and constructed specially for this purpose. An existing cupboard or compartment may be used, provided that it is modified for the purpose.

In both cases details of essential features of cupboard / compartment design, including air cupboard installation, are to conform to the following:

F BS 6798 (No cupboard ventilation is required --- see “Air

supply” for details)

F The position selected for installation MUST allow

adequate space for servicing in front of the boiler.

F For the minimum clearances required for safety and

subsequent service, see the wall mounting template and frame 2. In addition, sufficient space may be required to allow lifting access to the wall mounting plate.

GAS SUPPLY

The local gas supplier should be consulted, at the installation stage, in order to establish the availability of an adequate supply of gas. An existing service pipe must NOT be used without prior consultation with the local gas supplier. Natural gas boilers must be installed on a gas supply with a governed meter. A gas meter can only be connected by the local gas supplier or by a registered CORGI engineer.

Propane gas boilers MUST be installed with pipes, cylinders and pressure regulators fitted in accordance with BS.5482.1. Bulk tank installations MUST comply with the Home Office code of practice for storage of liquefied petroleum gas at fixed installations. The complete installation MUST be tested for gas soundness and purged as described in the above code.

The boiler is adjusted at the factory for use with the relevant supply gas. A working gas pressure equal to that stated in Table 1 MUST be available at the boiler inlet.

Where applicable, the appliance can be converted for G20--- Natural Gas or G31--- Propane Gas by using the appropriate conversion kit.

IMPORTANT Installation pipes MUST be fitted in accordance with BS. 6891. In IE refer to I.S. 813.2002. Pipework from the meter to the boiler MUST be of an adequate size, i.e. not less than 22 mm O.D. copper or 3/4” BSP iron.

FLUE INSTALLATION REQUIREMENTS

The flue must be installed in accordance with the recommendations of BS. 5440---1 2000. In IE refer to I.S. 813.2002.

The following notes are intended for general guidance.

1 The boiler MUST be installed so that the terminal is

exposed to external air.

2 It is important that the position of the terminal allows the

free passage of air across it at all times.

3 Minimum acceptable spacing from the terminal to

obstructions and ventilation openings are specified in Table 4.

4 Where the lowest part of the terminal is fitted less than 2m

(6’6”) above a balcony, above ground or above a flat roof to which people have access then the terminal MUST be protected by a purpose designed guard. Ensure that the guard is fitted centrally.

5 Where the terminal is fitted within 850mm (34”) of a plastic

or painted gutter or 450mm (18”) of painted eaves then an aluminium shield at least 750mm (30”) long should be fitted to the underside of the gutter or painted surface fitted centrally above the flue.

6 The air inlet/products outlet duct and the terminal of the

boiler MUST NOT be closer than 25mm (1”) to combustible material. Detailed recommendations on the protection of combustible material are given in BS. 5440--- 1:2000. In IE refer to I.S. 813.2002.

Table 4 --- Balanced flue terminal position

Terminal position

1 Directly below, above or along side

of an openable window, air vent or other ventilation opening

2 Below guttering, drain pipes or soil

pipes

3 Below eaves 25 mm ( 1”)

4 Below balconies or a car port roof 25 mm ( 1”)

5 From vertical drain pipes or soil

pipes*

6 From an internal or external corner

or to a boundary along side the terminal

Minimum spacing

300 mm (12”)

25 mm ( 1”)

mini HE --- Installation & Servicing

Page 9

GENERAL

7 Above adjacent ground, roof or

balcony level

8 From a surface or a boundary

facing the terminal.

9 From a terminal facing a terminal 1200 mm (48”)

10 From an opening in a car port (e.g.

door or window) into dwelling

11 Vertically from a terminal on the

same wall

12 Horizontally from a terminal on the

wall

* If the terminal is within 150mm of any vertical soil or drain pipe, an aluminium shield at least 400mm (15 3/4”) long should be fitted equi--- distant from the terminal and close to the pipe.

Vertical Terminals

13 Above the roof pitch with roof

slope of all angles.

Above flat roof

14 From single wall face

From corner wall faces

Twin Flue Applications

15 Centre distance between air inlet

and flue outlet ducts

** Where the twin flue ducts are positioned at or near the above minimum centres the wall sealing gaskets should be trimmed to allow them to fit flat to the wall. This should be done for both inside and outside wall gaskets

Terminals guards are available from boiler suppliers --- ask for Tower Flue Guard, Model K6. In case of difficulty seek advice from:

Grasslin UK Ltd.,Tower house, Vale Rise, Tonbridge, Kent TN9 1TB Tel. +44 (0) 1732 359 888 Fax No. +44 (0) 1732 354 455 www.tfc--- group.co.uk

IMPORTANT It is absolutely ESSENTIAL to ensure, in practice, that products of combustion discharging from the terminal cannot re --- enter the building or any other adjacent building through ventilators, windows, doors other sources of natural air infiltration, or forced ventilation / air conditioning.

If this should occur the appliance MUST be turned OFF, labelled as “unsafe” until corrective action taken.

300 mm (12”)

600 mm (24”)

1200 mm (48”)

1500 mm (60”)

300 mm (12”)

600 mm (24”)

1000 mm (40”)

120mm (5”) **

AIR SUPPLY

It is NOT necessary to have a purpose--- provided air vent in the room or internal space in which the boiler is installed. Neither is it necessary to ventilate a cupboard or compartment in which the boiler is installed, due to the low surface temperatures of the boiler casing during operation; therefore the requirements of BS6798, Clause 12, BS 5440:2 and in IE I.S. 813:2002 may be disregarded.

WATER CIRCULATION SYSTEM

The boilers are designed for connection to pressurised, fully pumped, sealed water central heating systems ONLY. The domestic hot water (DHW) calorifier is incorporated within the combi boiler and only requires connection to the mains water supply.

Additional Pumps.

The boiler is supplied with an integral circulating pump. If the boiler is to be used in conjunction with any additional circulating pumps, please contact the Technical Helpline for advice on application.

IMPORTANT

A minimum length of 1m of copper pipe MUST be fitted to both flow and return connections from the boiler before connection to any plastic piping.

Ensure that the mains water supply pressure is adequate to provide the required DHW flow rate. Refer to Table 1 on page 4.

The central heating system should be in accordance with BS. 6798 and, in addition, for smallbore and microbore systems BS. 5449.

The domestic hot water system should be in accordance with BS. 5546 and BS. 6700.

Copper tubing to BS 2871:1 is recommended for water carrying pipework and MUST be used for pipework carrying potable water.

Any soldered joints on potable water pipework MUST NOT be made with solder containing lead.

Ancillary pipework not forming part of the useful heating surface should be lagged to prevent heat loss and any possible freezing --- particularly where pipes run through roof spaces or ventilated underfloor spaces.

Draining taps should be at least 1/2” BSP nominal size and be in accordance with BS 2879.

WATER TREATMENT

Central Heating

Antifreeze fluid, corrosion and scale inhibitor fluids suitable for use with boilers having copper heat exchangers may be used in the central heating system.

IMPORTANT

The application of any other treatment to this product may render the guarantee of Caradon Ideal Limited INVALID.

Caradon Ideal Limited recommend Water Treatment in accordance with the Benchmark Guidance Notes on Water Treatment in Central Heating Systems.

Caradon Ideal Limited recommend the use of Fernox, GE Betz Sentinel or Salamander water treatment products, which must be used in accordance with the manufacturers instructions.

Notes.

1. It is most important that the correct concentration of the water treatment products is maintained in accordance with the manufacturers’ instructions.

2. If the boiler is installed in an existing system any unsuitable additives MUST be removed by thorough cleansing. BS 7593:1992 details the steps necessary to clean a domestic heating system.

3. In hard water areas, treatment to prevent lime scale may be necessary --- however, the use of artificially softened water is NOT permitted.

4. Under no circumstances should the boiler be fired before the system has been thoroughly flushed.

mini HE --- Installation & Servicing

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GENERAL

Domestic Hot Water

In hard water areas where mains water can exceed 200ppm Total Hardness (as defined by BS 7593:1993 Table 2) a scale reducing device should be fitted into the boiler cold supply within the requirements of the local water company. The use of artificially softened water, however, is NOT permitted.

Caradon Ideal Limited recommend the use of Fernox Qantomat, GE Betz Sentinel Combiguard and Calmag CalPhos I scale reducing devices, which must be used in accordance with the manufacturers’ instructions.

For further information contact:

3 ELECTRICAL SUPPLY

Warning. This appliance must be efficiently earthed.

Wiring external to the appliance MUST be in accordance with the current I.E.E. (BS.7671) Wiring Regulations and any local regulations which apply. For Ireland reference should be made to the current ETCI rules for electrical installations.

Fernox Cookson Electronics Forsyth Road Sheerwater Woking Surrey GU21 5RZ +44 (0) 1799 550811

Salamander (Eng) Ltd Reddicap Trading Estate Sutton Coldfield West Midlands B75 7BY

+44 (0) 121 378 0952

The point of connection to the mains should be readily accessible and adjacent to the boiler, except for bathroom installations where the point of connection to the mains MUST be situated outside of the bathroom.

Note. Where a room sealed appliance is installed in a room containing a bath or shower then the appliance and any electrical switch or appliance control utilising mains electricity should be so situated that it cannot be touched by a person using the bath or shower.

Calmag Ltd. Unit 4---6 Crown Works Bradford Road Sandbeds Keighley West Yorkshire BD20 5LN +44 (0) 1535 210320

GE Betz Sentinel Division Foundry Lane Widnes Cheshire WA8 8UD

+44 (0) 151 420 9563

4 SEALED SYSTEM REQUIREMENTS

Central Heating

Note. mini HE boilers are suitable for fully pumped pressurised sealed systems only.

REQUIREMENTS

1 General

The installation must comply with the requirements of BS. 6798 and BS. 5449.

2 Flow Temperature

The installation should be designed to work with flow temperatures of up to 90 °C.

3 Working Pressure

All components of the system must be suitable for a working pressure of 3 bar (45 lb/in2) and temperature of 110 ° C. Extra care should be taken in making all connections so that the risk of leakage is minimised.

The following components are incorporated within the appliance:

a. Circulating pump.

b. Safety valve; with a non--- adjustable pre--- set lift pressure of 3 bar (45lb/in2).

c. Pressure gauge; covering a range of 0--- 4 bar.

d. 6 litre expansion vessel; with an initial charge pressure of

0.7 bar (10.5 lb/in2).

For further details refer to BS.5449:1 and the British Gas Corporation publication ’Specifications for Domestic Central Heating and Hot Water’.

4 Filling the system

Fill the system through a temporary hose connection from a draw---off tap supplied from a service pipe under mains pressure. Where the mains pressure is excessive a pressure reducing valve shall be used to facilitate filling.

When installing the filling connection provided with the boiler an additional WRAS approved valve must be fitted to the mains water supply upstream of the double check valve to fully comply the Water Regulations

Stop valve Additional stop valve

CH return

Temporary hose (disconnect after filling)

System filling and make ---up

Proceed with the following:

F Thoroughly flush out the whole of the system with cold

water before fitting the boiler.

F Fill and vent the system until the pressure gauge registers

1.5 bar (22 lb/in2). Examine for leaks.

F Release water from the system until a pressure of 1 bar

(15 lb/in2) is reached.

To avoid getting debris on the valve seat, do not use the safety valve to do this.

F Light the boiler and heat the system to the maximum

working temperature. Examine for leaks.

F Turn off the boiler and drain the system while still hot. F Refill and vent the system. F Re --- pressurise the system to the desired charge pressure

(see Table 5).

Hose unions

Mains Water Supply

Double check valve assembly Note direction of flow

mini HE --- Installation & Servicing

Page 11

GENERAL

mH2

Table 5

System charge pressure (bar)

Safety valve setting 3.0

Vessel pre--- charge pressure (bar)

System volume (litres) Volume of expansion vessel

75 --- --- ---

100 0.3 0.8 1.4

125 1.8 2.5 3.2

150 3.4 4.2 5.0

175 5.0 6.0 7.0

200 6.5 7.6 8.7

225 8.1 9.3 10.6

250 9.6 11.1 12.4

275 11.2 12.8 14.3

300 12.8 14.5 16.1

Multiply this factor by system volume and deduct 6 litres to obtain size of additional vessel for other system volumes.

0.5 0.7 1.0

0.7

in addition to 6 litre unit

fitted to boiler

0.063 0.069 0.074

5 Size of expansion vessel

For the system water expansion to be contained by the 6 litre expansion vessel the cold system volume must not exceed:

96 litres when pressurised to 0.5 bar (cold)

88 litres when pressurised to 0.7 bar (cold)

81 litres when pressurised to 1.0 bar (cold)

If the pressure exceeds 2.65 bar when the boiler is up to temperature with all radiators in use then an additional expansion vessel MUST be installed on the return pipework.

For expansion volumes see Table 5.

Guidance on vessel sizing is given in BS 7074:1 and BS 5449

For IE refer to the current edition of I.S. 813.

6 Hydraulic Loss Remaining pump capacity

0 200 400 600 800 1000 1200 1400

Flow rate l/hour

7 Draining the system

Draining taps MUST be located in accessible positions to permit the draining of the whole central heating system, including the central heating side of the boiler. The taps should be at least 1/2” BSP nominal size and be in accordance with BS 2879.

mini HE --- Installation & Servicing

Page 12

GENERAL

5 BOILER CONTROL INTERLOCKS

Thermostatic radiator valves.

Caradon Ideal Ltd. support the recommendations made by

leading manufacturers of domestic heating controls that heating systems utilising full thermostatic radiator valve control of temperature in individual rooms should also be fitted with a room thermostat controlling the temperature in a space served by radiators not fitted with such a valve as stated in BS5449. Such an arrangement will provide for a more efficient control of the environment and will also avoid the continuous running of the circulation pump during programmed heating ON periods, saving electrical energy.

It is therefore strongly recommended that, when thermostatic radiator valves are used, the space heating temperature control over a living/dining area or a hallway, having a heat requirement of at least 10% of the boiler output, is achieved using a room thermostat whilst other rooms are individually controlled by thermostatic radiator valves as stated in BS5449.

6 DOMESTIC HOT WATER

REQUIREMENTS

1 The domestic hot water service must be in accordance

with BS 5546 and BS 6700.

2 For the minimum and maximum working pressures of the

mini HE C24 and mini HE C28 domestic hot water circuit refer to Table 1, page 4.

3 The cold water supply pipe should be flushed before

fitting the boiler.

4 The boilers are suitable for connection to most types of

washing machine and dishwashing appliances.

For further information refer to “Good Practise Guide 143” a publication of the energy efficiency office, available from the building research establishment Garston Watford WD2 7JR tel: +44 (0) 1923 664258

The boiler is fitted with an automatic internal bypass. No further system bypass is required.

Typical installation

TRV

5 When connecting to suitable showers, i.e. those designed

for modulating domestic hot water, ensure that:

a. The cold inlet to the boiler is fitted with an approved

anti---vacuum or syphon non--- return valve.

b. Hot and cold supplies are of equal pressure.

6 Hard water areas

In areas where the water is ’hard’ it is recommended that a proprietary scale---reducing device is fitted into the boiler cold supply, within the requirements of the local water company.

Room T/stat

Balancing valve

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Page 13

GENERAL

7 BOILER WATER CIRCUIT DIAGRAM

1 Domestic hot water (DHW) heat exchanger 2 Domestic hot water (DHW) flow switch

3 Domestic hot water (DHW) outlet pipe

4 Domestic cold water inlet cock

5 Three ---way diverter valve 6 Main circuit drainage cock

7 Central heating flow cock 8 By ---pass valve 9 Central heating (CH) return cock 10 3 bar pressure relief valve 11 Gas cock 12 Expansion vessel 13 Gas valve inlet pressure tap 14 Modulating gas valve 15 Burner pressure tap 16 Flame detection electrode 17 Ignition electrodes 18 Burner 19 Combustion chamber 20 Primary heat exchanger 21 Fan 22 Air pressure switch 23 Venturi device 24 Flue outlet pipe 25 Air intake pipe 26 Automatic air vent 27 Overheat thermostat

28 Pump 29 Pump vent plug

30 Water circuit temperature probe 31 CH flow switch 32 DHW temperature probe 33 CH circuit temperature/pressure gauge 34 Recuperator 35 Flue thermostat 36 Condensate trap 37 Condensate drain pipe

mini HE --- Installation & Servicing

Page 14

8 BOILER ASSEMBLY ---

Exploded View

INSTALLATION

9 10 11

23 21

1 Air pressure switch

2 Recuperator

3 Condensate trap

4 Overheat thermostat

5 Condensing to main heat

exchanger connection pipe

6 Primary heat exchanger

7 Inner case cover

8 Flame detection electrode

9 Ignition electrodes

10 Heat exchanger return pipe

11 Auto air vent

12 Main circuit drainage cock

13 Pump

1922

14 DHW flow switch

15 DHW Thermistor

16 Ignition pcb

17 Right hand panel

18 Boiler front panel

19 Appliance data badge (inside)

20 Left hand panel

21 CH circuit pressure gauge

22 Model identification & instructions

23 Control panel door

24 Main control pcb

25 CH Thermistor

26 CH flow switch

27 Heat exchanger flow pipe

28 Return manifold

29 3 way diverter valve

30 DHW heat exchanger

31 Bypass pipe

32 3 bar pressure relief valve

33 Gas valve

34 Gas valve outlet pipe

35 Injector manifold

36 Burner

37 Flue hood

38 Fan

39 Expansion vessel

40 Venturi

41 Flue thermostst

mini HE --- Installation & Servicing

Page 15

INSTALLATION

9 UNPACKING

The boiler is supplied fully assembled in one pack A, together with a standard flue assembly for lengths up to 960 mm (37” 3/4), rear or side flue outlet, in pack B.

Unpack and check the contents.

Pack A contents

A The boiler.

B Hardware pack

C Wall mounting plate

D Wall mounting template

E User’s, Installation & Servicing instructions.

F Filling loop assembly

Hardware pack contents

F 22 mm CH connection pipe --- 2 off. F 22 mm Gas supply connection pipe --- 1 off. F 15 mm DHW cold inlet connection pipe --- 1 off. F 15 mm DHW hot outlet connection pipe --- 1 off. F 1/2” connection nut --- 2 off. F 1/2” sealing washer --- 3 off. F 3/4” sealing washer --- 6 off. F 3/4” Gas supply isolating valve --- 1 off. F 3/4” CH circuit isolating valve --- 2 off. F 1/2” DHW cold inlet isolating valve --- 1 off.

Pack B contents

G Air intake pipe ø 100 mm (4”), flue pipe ø 60 mm (2” 3/8)

with terminal grille assembly

H Centring spring

I Turret--- air pipe gasket

J Flue pipe gasket

K Boiler--- turret gasket

L Flue turret

M Self tapping screws 4,8x13 --- 4 off

N Wall finishing gasket --- internal (plastic)

O Wall finishing gasket --- external (rubber)

Optional extras, if ordered, are available in separate boxes.

F Electronic programmer kits --- 24 hrs & 7 day F Extension duct kit pack D (ø 60/100) F Flue support kits ø 80, 100, 125 F Vertical outlet flue kit with elbow (ø 60/100) F 90° Elbow kit (ø 60/100) F 45° Elbow kit (ø 60/100) F Roof flue kit (ø 80/125) F Universal weather collar (for roof flue kit) F Flat roof weather collar (for roof flue kit) F Extension duct kit (ø 80/125) F 90° Elbow kit (ø 80/125) F 45° Elbow kit (ø 80/125) F Condense drain vertical (ø 80/125) F Twin pipe kit (ø 80) with air and flue terminals F Extension duct kit (ø 80) F 90° Elbow kit (ø 80) male---female F 45° Elbow kit (ø 80) male---female F Vertical condense drain (ø 80) F Horizontal condense drain (ø 80) F Condense trap F Stand--- off bracket F Natural gas to LPG conversion kit F LPG to natural gas conversion kit F Condensate pump kit

INSTALLATION

10 PACKAGING

To unpack the boiler refer to the instructions on carton end flap.

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Page 16

INSTALLATION

11 FITTING THE FLUE SYSTEM

The minimum and maximum equivalent length for co---axial pipes ø 60 ---100 and ø 80 ---125 mm are given in Table 6.

The minimum and maximum equivalent length for ø 80 mm twin pipe systems are given inTable 7.

For roof flue systems having a flue length greater than 3m and all twin pipe systems, a condensate drain kit must be fitted at the lowest point in the system. See the list of optional extras (frame 9) for available drain kits.

Refer to the assembly instructions contained within the chosen flue kit packaging for the correct assembly and

INSTALLATION

installation.

The horizontal sections of flue pipes must have a slope not less than 1.5 deg. (25 mm per metre) towards the boiler.

In the flue kit of pack B the flue pipe is angled within the air duct therefore the air duct must be horizontally installed.

In the case that one or more extensions need to be used they must be adequately supported so that there is no sag in the flue pipe and a minimum fall of 1.5 deg. (25 mm per metre) over the whole length towards the boiler is ensured.

Horizontal Concentric

Air duct

Rear Outlet Wall thickness + 125 mm

Rear outlet+Stand--- off Wall thickness + 160 mm

Side Outlet --- RH Wall thickness + Gap +62 mm

Side Outlet --- LH Wall thickness + Gap +208 mm

Twin pipe flue kits

For calculation of total flue length, the distance MUST be measured from the centreline of the flue duct/air duct connection to the end of the flue outlet grille/air inlet duct.

For each additional 45° M&F and 90° M&F flue bend used, the maximum permissible length of flue system must be reduced by 0,9m or 1,65m respectively.

Two restrictors with different sizes are supplied with the twin pipe kit and have to be installed between the boiler and the air intake adapter as indicated in the following picture.

The restrictor to be used and the lengths of allowable equivalent flue outlet / air inlet ducts are indicated in Table 7 and in the following graph.

The restrictor size is marked on its body.

Air intake adapte r

Table 6

Minimum Maximum

Co---axial 60---100 0.3 (11.8”) 2.7 (8’ 10”)

Co---axial 80---125 0.5 (19.7”) 8.5 (27’ 10”)

Co---axial Flue kits.

Horizontal. For calculation of total flue length, the distance MUST be measured from the centreline of the concentric elbow to the end of the terminal.

Vertical outlet For calculation of total flue length, the distance MUST be measured from the centreline of the outlet connector at the boiler top panel to the end of the terminal grille.

For each additional 45° and 90° flue bend used, the maximum permissible length of flue system must be reduced by 1 m or 1,5 m respectively.

Cutting lengths of flue and air ducts

Measure the wall thickness and, when using a side outlet, the gap between the inner wall and the boiler side casing. Use the following chart to calculate the cutting length of air duct.

Mark the air duct making reference on the groove.

Cut the flue duct at the same level of the air duct edge.

Cut this end

Groove

Restrictor

Gasket

Table 7

Equivalent pipe length

Restrictor

(air duct + flue duct)

Between 1 (39“) and 15 m (49’ 2”) ø 50 mm

More than 15 m (49’ 2”) up to 30 m (98’ 5”) ø 55 mm

Flue exhaust ”a”

Restrictor

50 mm

0 2 4 6 8 10 12 14 16 18 20 22 24 26 2 8 30 32

Restrictor

55 mm

Allowed values

Air intake ”b”

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Page 17

INSTALLATION

Cutting lengths of flue and air ducts

Measure the wall thickness and, when using a side outlet, the gap between the inner wall and the boiler side casing. Use the following chart to calculate the cutting lengths of both flue and air ducts.

Mark the air duct and flue duct making reference on the groove.

Groove

12 REAR FLUE ASSEMBLY

Legend

1 Wall finishing gasket --- external (rubber) 2 Self tapping screw 4,2x13 3 Flue turret 4 Boiler --- turret gasket 5 Flue pipe gasket 6 Turret--- air pipe gasket 7 Centring spring 8 Air/flue pipe with terminal grille assembly 9 Wall finishing gasket --- internal (plastic)

Twin Pipe

Air duct

Rear Outlet Wall thickness + 130 mm

Rear outlet+Stand--- off Wall thickness + 165 mm

Side Outlet --- RH Wall thickness + Gap + 187 mm

Side Outlet --- LH Wall thickness + Gap + 93 mm

Flue Duct

Rear Outlet Wall thickness + 130 mm

Rear outlet+Stand--- off Wall thickness + 165 mm

Side Outlet --- RH Wall thickness + Gap +67 mm

Side Outlet --- LH Wall thickness + Gap + 213 mm

INSTALLATION

13 WALL MOUNTING TEMPLATE

(rear flue)

IMPORTANT

Detailed installation steps are given directly on the wall mounting template

1 Tape the template into the selected position. 2 Ensure squareness by hanging a plumbine. 3 Mark onto the wall the following:

a. the wall mounting plate screw positions b. the position of the flue duct.

(Mark the centre of the hole as well as the circumference)

4 Remove the template from the wall

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Page 18

INSTALLATION

14 WALL MOUNTING TEMPLATE

(side flue)

IMPORTANT

Detailed installation steps are given directly on the wall mounting template

1 Tape the template into the selected position.

2 Ensure squareness by hanging a plumbine.

3 Mark onto the wall the following:

a. the wall mounting plate screw position b. Extended the centre line as shown.

Mark the flue ductcentre from the corner (see diagram

INSTALLATION

and template)

Note. mark the centre of the hole as well as the circumference. If extension duct kit pack D has to be used, the pipes must have the correct slope as detailed in frame 11.

4 Remove the template from the wall

15 DRILLING THE WALL

Rear flue shown

IMPORTANT

Ensure that, during the cutting operation, masonry falling outside the building does not cause damage or personal injury.

1 Cut the flue hole (preferably with a 5” core boring tool),

ensuring that the hole is square to the wall.

2 Drill the fixing holes with an 8mm (5/16”) masonry drill.

Fit suitable wall plugs (not provided).

Note. If the teminal is to be sited within 25 --- 40 mm of a corner or vertical pipe (refer to Table 4) then the hole MUST be accurately cut and the rubber weather seal trimmed.

5” diameter flue hole

Section through wall

Extended centre

Spirit level

16 FITTING THE WALL

MOUNTING PLATE

Refer to frame 18 for service connections.

Fit the wall mounting plate

Directly to the wall

F Offer up wall mounting plate. F Screw through the fixing holes using 3 off no. 14x2”

screws (not provided).

F Check alignment with spirit level. F Tighten screws.

Note: Check all of the hole positions before drilling.

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Page 19

INSTALLATION

17 MOUNTING THE BOILER

Lift the boiler onto the wall mounting plate locating the bar at the rear of the back panel assembly into the bracket.

As added protection, the boiler should be lifted with the lower polystyrene packaging in place.

Lower the boiler into position.

Remove the lower packaging. Remove the front and side panels (refer to frame 22) and strip off the protective coating. The panels may be placed to one side and re---fitted when the installation is complete.

Note. Before fitting the flue system, fili the condensate trap within the boiler by pouring a cupful of water into the flue outiet A. Take care to ensure that the water is only poured into the flue outiet, and does not spill into the boiler casing.

Fit the flue system referring to the instructions contained with the kit.

Make good the internal wall surface using the seal provided.

18 CONNECTIONS

Fit the service valves washers and tail pipes as shown.

INSTALLATION

Central Heating flow

Domestic hot water outlet

Connect to the tail pipes by proprietory fittings.

The pipework may be directed down or through the rear wall as required.

The pipework may be directed upwards by using the optional stand off bracket kit. See illustration for upward pipework routing

Gas inlet

Domestic cold water inlet

Central Heating return

19 SAFETY VALVE DRAIN

The discharge pipe should be positioned so that the discharge of water or steam cannot create a hazard to the occupants of the premises or damage to electrical components and wiring.

Pressure relief valve

mini HE --- Installation & Servicing

Discharge pipe

Page 20

INSTALLATION

20 CONDENSATE DRAIN

Refer also to the British Gas document: “Guidance Notes for the installation of Domestic Gas Condensing Boilers” (1989).

The condensate drain provided on the boiler must be connected to a drainage point, preferably within the building.

The boiler includes a trap that prevents combustion products entering the drain. However an additional trap with a seal of at least 75 mm and an air break between the traps is required if the condensate drain pipe is connected to sanitary pipework.

INSTALLATION

The length of the condensate pipe should be kept at minimum and must be arranged so that obstruction (e.g.

Condensate drain

Additional trap

21 ELECTRICAL CONNECTIONS

Warning. This appliance MUST be efficiently earthed

A mains supply of 230 V ~ 50 Hz is required.

Mains wiring should be 3 core PVC insulated flexible cord NOT LESS than 0.75 mm2(24 x 0.2mm) and to BS. 6500, Table 16. (0.5mm2flex is not acceptable --- for mechanical, not electrical reasons.)

Mains wiring external to the boiler MUST be in accordance with the current I.E.E. (BS7671) Wiring Regulations and any local regulations.

through freezing) of external drainage pipework does not give rise to spillage within the dwelling.

If a part of the drainpipe runs externally this part should be kept as short as possible and protected to reduce the risk of freezing.

IMPORTANT

If excessive external pipework cannot be avoided an additional condensate removal pump (available as an option) and insulation are recommended to prevent possible freezing.

The drain outlet on the boiler is a 25 mm o.d. plastic pipe. This size must not be reduced below 21.5mm o.d. (standard overflow pipe) in any part of its length.

All pipework and fittings in the condensate drain system must be made of plastic. No other materials may be used.

To avoid condensate being trapped:

--- the drainpipe should be run with a fall of at least 2.5° (45 mm/m) away from the boiler;

--- the number of bends and joints should be kept at minimum;

--- the drainpipe should be adequately fixed to pevent pipe sagging.

For Ireland reference should be made to the current ETCI rules for electrical installations.

The supply connection is intended to be made via a double pole switch having a 3 mm (1/8”) contact separation in both poles, serving only the boiler and system controls. A 3 pin UNSWITCHED socket may, alternatively, be used.

The fuse rating should be 3 A.

For external controls wiring see frame 25. Note: the switch contacts of any external programmer, room or frost thermostat must be volt free. Connecting a switched live feed to external controls terminal block may be dangerous and will result in serious damage to the boiler.

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Page 21

INSTALLATION

Mains

22 ELECTRICAL CONNECTIONS

Incoming mains wiring detail

To gain access to the power supply and external controls terminal blocks:

1 Remove the screws A and the front panel of the case.

2 Remove the screws B.

3 Loosen the screws C.

4 Remove the side panels or move the lower part of the side

panels and pull the control panel.

When completely pulled out, the panel can rotate 45° downwards to facilitate the operations on the internal parts.

5 Loosen the screws D and remove the service panel.

INSTALLATION

Volt free contacts Thermostat link Remove when wiring external thermostats.

Refer to frame 25

L N

Power supply terminal block

External controls terminal block

Note: Ensure that the lengths of the current conductors are shorter than the earth conductor so that if the cable slips in its anchorage the current carrying conductors become taut before the earth conductor.

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Page 22

INSTALLATION

23 PICTORIAL WIRING

mini HE C24, mini HE C28

Wiring diagram for boiler equiped with full sequence ignition device type: Bertelli & Partners FM30

External controls Electric supply

123

terminal blockterminal block

Flue

thermostat

gnye

Safety

thermostat

bnbn

Fan Air pressure

switch

gnye

electrodes

COM

INSTALLATION

Ignition

Flame detection

electrode

gybnbu

bu gy

Electronic

control p.c.b.

bn = brown bu = blue bk = black wh = white rd = red gy = grey gn = green ye = yellow vt = violet og = orange gnye = green/yellow

bk bk

probe NTC

wh rd

DHW flow

switch flow switch

Primary circuitDHW temperature

gnye

bk bu bn

gnye

P.C.B. #1

CH temperature

gnye

bn bu bk bn

P.C.B. #2

probe NTC

bu bn bk bu

bkbnbu

312

bu bn bk bu

Full sequence

ignition device

gnye

Condensate

gnye

gnye gnye

bk gyrd

gnye

trap

gnye

Electronic control p.c.b. Pin position ref. numbering

3 2 1

Three way

diverter valve

Pump

Full sequence ignition device

P.C.B. #1 P.C.B. #2

313029282726252423

1617181920

Pin position ref. numbering

116 115 114

113 6 7

112 8

111

110 9

109

108

107

106

12 13 14

105

104

103

102

101

117

118

119

120 121

122

Modulating

gas valve

rd bk wh

Time switch

(optional)

mini HE --- Installation & Servicing

Page 23

INSTALLATION

Wiring diagram for boiler equiped with full sequence ignition device type: Honeywell FPLD

External controls Electric supply

123

gybnbu

Electronic

control p.c.b.

bn = brown bu = blue bk = black wh = white rd = red gy = grey gn = green ye = yellow vt = violet og = orange gnye = green/yellow

terminal blockterminal block

Flue

thermostat

gnye

bu gy

Fan Air pressure

Safety

thermostat

bnbn

gnye

switch

COM

Ignition

electrodes

Flame detection

electrode

INSTALLATION

gnye

bk bu bn

P.C.B. #1

gnye

bn bu bk bn

P.C.B. #2

bu bn bk bu

Full sequence

ignition device

Condensate

gnye

gnye gnye

trap

gnye

bk bk

probe NTC

Electronic control p.c.b. Pin position ref. numbering

3 2 1

DHW flow

wh rd

switch flow switch

Primary circuitDHW temperature

P.C.B. #1 P.C.B. #2

5 6 7

313029282726252423

1617181920

9 10 11

12 13 14

CH temperature

probe NTC

Three way

diverter valve

Full sequence ignition device Pin position ref. numbering

116 115 114

113

112 111 110 109 108 107

106

105 104 103 102

101

bkbnbu

312

gnye

Pump

117

118

119

120 121

122

bk gyrd

gnye

Modulating

gas valve

rd bk wh

Time switch

(optional)

gnye

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Page 24

24 FUNCTIONAL FLOW DIAGRAM

mini HE C24, mini HE C28,

INSTALLATION

Pump

CH temp. probe

DHW temp. probe

Three way div. valve

Gas Valve (modulation coil)

Main

control pcb

23 16 17 30 31

P.C.B. #1 P.C.B. #2

INSTALLATION

Ignition electrodes

105

104

103

102

101

117

118

119

107

106

Ignition pcb

108

109

110

rd rd

bk bk

rd bkbu

122

120

bk bu

113114 115

111

112

Gas Valve (on--- off operators)

Detection electrode

Air pressure switch

Fan

Flue thermostat

Safety thermostat

Condensate trap

DHW flow switch

CH flow switch

mini HE --- Installation & Servicing

Page 25

INSTALLATION

25 EXTERNAL ELECTRICAL CONTROLS

Wiring external to the boiler MUST be in accordance with the current I.E.E. (BS.7671) Wiring Regulations.

For Ireland reference should be made to the current ETCI rules for electrical installations.

The fuse rating should be 3A.

Route the electrical supply flexible cord and the external control flexible cord as illustrated. Lock the flexible cords in place with the clamps provided.

230V supply

ELECTRICAL CONNECTIONS FOR A COMBI BOILER

Optional Programmer Kits

Optional digital programmer kits are available with their relevant instructions.

Both 24hr and 7day kits are available.

Note: the switch contacts of any external programmer, room or frost thermostat must be volt free. Connecting a switched live feed to external controls terminal block may be dangerous and will result in serious damage to the boiler.

Room Thermostat

This should be wired as shown in diagrams A.

Frost protection

Central heating systems fitted wholly inside the house do not normally require frost protection as the house acts as a ‘storage heater’ and can normally be left at least 24 hours without frost damage.

However, if parts of the pipework run outside the house or if the boiler will be left off for more than a day or so then a frost thermostat should be wired into the system. To maintain frost protection with the programmer selector

switches set to OFF, all the controls MUST be left in the running position.

The frost thermostat should be sited in a cold place but where it can sense heat from the system.

Wiring should be as shown, with minimal disturbance to other wiring.

External Programmers

On the combi boilers, this should be of the single channel type (as this boiler does not incorporate a pre--- heat facility for the instantaneous hot water service).

Programmers with room thermostat --- see diagram B.

Note. lf the boiler is installed in a garage it may be necessary to fit a pipe thermostat, preferably on the return pipework.

Earths are not shown for clarity but must never be omitted.

Optional frost’stat

Room thermostat

L N

Power supply terminal block

External controls

terminal block

External programmer

Optional frost’stat

N.B. These diagrams are schematic only and do not show external terminal strips etc.

Room thermostat

L N

Power supply terminal block

External controls terminal block

INSTALLATION

mini HE --- Installation & Servicing

Page 26

26 INITIAL LIGHTING

INSTALLATION

A B C D E F

INSTALLATION

Legend

A Appiance On lamp

B Domestic hot water temperature control

C Main switch and radiator temperature control

D Boiler reset button

E Lock--- out signal lamp

F Programmer (optional)

G System pressure and temperature gauge

Central Heating flow

Domestic hot water outlet

Gas inlet

Domestic cold water inlet

Central Heating return

IMPORTANT Before lighting the boiler you should note especially that:

1 Check that all the drain cocks are closed and any valves

in the flow and return are open.

2 Check that the system has been filled and pressurised

and that the boiler is not air locked.

3 Remove boiler front panel.

4 Ensure the dust cap on the automatic air vent is open at

least one full turn and leave this permanently open

5 Ensure that the pump is free to rotate

i Remove the vent plug ii Using a screwdriver, rotate the shaft several times iii Replace the vent plug

Note. Some slight water leakage will occur

6 Remove the screw in the burner pressure test point

indicated on the following picture and connect a gas pressure gauge via a flexible tube. Be sure to select the correct pressure test point. Refer to Tables for pressures.

7 Check that the gas service cock is ON. 8 Switch the electricity supply ON and check that all

external controls are calling for heat.

9 Set the main switch C to ’ON’. Following a pre --- purge

period the gas control solenoid valve should open and the spark commence, continuing until the burner is established.

10 Check that the burner lights smoothly. If this does not

occur within 20 seconds, turn the main switch to ’O’ position, wait for 5 seconds then try again by pressing the reset button ’D’. If the burner still does not light, refer to the ’Fault Finding’ section.

11 Test for gas soundness around ALL boiler gas

components, using leak detection fluid.

12 Operate the boiler for 10 minutes to stabilise the burner

temperature.

13 Check that the burner pressures are correct. The boiler is

factory pre--- set and should not need adjustment.

However if adjustment is required refer to frame 27. 14 Set the boiler main switch to ’O’. 15 Remove the pressure gauge and tube. Replace the

sealing screw in the pressure test point. Ensure a gas

tight seal is made. 16 Refit the boiler front panel using the screws previously

removed. 17 Switch the boiler on again.

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Page 27

27 TO ADJUST PRESSURES

Nomenclature of the parts on the gas valve

A Modulation operator’s electric connectors

B Minimum gas pressure adjustment

C Maximum gas pressure adjustment

D Gas valve inlet pressure test point

E Burner pressure test point

INSTALLATION

(burner pressure).

By rotating clockwise the pressure increases. 10 Turn the boiler off and re---connect the wire to the

modulating operator. 11 Start the boiler and check again the maximum gas

pressure setting. 12 Turn the boiler off and disconnect the gauge and close the

gas valve outlet pressure test point E

Important: after the gas pressure checks and any adjustment operations, all of the test points must be sealed.

Ignition rate adjustment

1 Turn on the boiler. 2 Check that the boiler lights up uniformly and adjust the

ignition gas pressure, if necessary.

To adjust the ignition gas pressure:

3 Open the gas valve outlet pressure test point E and

connect the gauge. 4 Loosen the screws F and remove the service panel

INSTALLATION

1 Remove the front panel of the case. 2 Open the gas valve inlet pressure test point D at the valve

input, connect a suitable pressure gauge and check the

gas pressure of the supply network. 3 Remove the gauge and close the pressure test point D. 4 Open the burner pressure test point E and connect the

gauge. 5 Remove the protection cap from the mechanical pressure

adjustment components (B and C) 6 Start the boiler at its maximum power.

Operate the boiler in DHW mode or ensure that the boiler

is not range rated if the test is carried out in CH mode.

Maximum valve setting

7 If necessary, rotate the maximum gas pressure

adjustment C using a spanner until you obtain the

required pressure as indicated on Table 1 at page 4

(burner pressure).

By rotating clockwise the pressure increases.

Minimum valve setting

8 Disconnect one of the two connectors A. 9 If necessary, rotate the minimum gas pressure adjustment

B using a pozidrive screwdriver until you obtain the

required pressure as indicated on Table 1 at page 4

Service panel

5 set dip --- switch ”3” to the OFF position and adjust

potentiometer marked “ACC” with a screwdriver until correct ignition gas pressure is obtained.

ACC

OFF

Suggested ignition pressures:

Natural gas G20 --- 6 (2,4) mbar (in w.g.) Propane G31 --- 13 (5,3) mbar (in w.g.)

mini HE --- Installation & Servicing

Page 28

INSTALLATION

28 ANTI CYCLING SETTING

If the dipswitch number 4 on the main P.C.B. is set to the ’ON’ position it will activate the re--- ignition delay period of approximately 3 minutes. When dipswitch number 4 is set to the ’OFF’ position there will be approximately 30 seconds re---ignition delay period.

29 COMMISSIONING AND TESTING

INSTALLATION

The benchmark Logbook or equivalent self certification should be completed and signed to demonstrate compliance with Building Regulations.

A. Electrical Installation

Checks to ensure electrical safety should be carried out by a competent person.

ALWAYS carry out the preliminary electrical system checks, i.e. earth continuity, polarity, resistance to earth and short circuit, using a suitable test meter.

3 minutes 30 sec.

1 2 3

OFF

B. Gas Installation

1 The whole of the gas installation, including the meter,

should be inspected and tested for soundness and purged in accordance with the recommendations of BS.

6891. In IE refer to I.S. 813:2002.

2 Purge air from the gas installation by loosening the gas

cock union and purge until gas odour is detected.

3 Retighten the union and test for gas soundness.

WARNING. Whilst effecting the required gas soundness test and purging air from the gas installation, open all windows and doors, extinguish naked lights and DO NOT SMOKE.

123

OFF

30 GENERAL CHECKS

Make the following checks for correct operation:

1 Hot water.

a. Fully open all DHW taps in turn and ensure that water flows freely from them.

b. Close all taps except the furthest one from the boiler and check that the boiler is firing at maximum rate.

c. Ensure that DHW temperature of approximately 35 ° C rise is obtained at the tap. This corresponds to a flow rate of about

litres/min (gpm)

10.1 (2.2) mini HE C24

11.7 (2.6) mini HE C28

d. Turn off the DHW tap.

2 Central heating (all models)

Operate each control separately and check that the main burner or circulating pump, as the case may be, responds.

3 Gas rate --- G20

Check the boiler gas rate when the boiler is at full output.

The gas rate checked at the gas meter, with no other appliance in use will normally be:

litres/min (ft3/min)

44.2 (1.56) mini HE C24

51.2 (1.81) mini HE C28

If this check is not possible, ensure that the burner pressure is:

models

10.8 (4.3) mbar (in. w.g.) for the model mini HE C24 and

10.0 (4.0) mbar (in. w.g.) for the model mini HE C28.

mbar (in. w.g.)

10.8 (4.3) mini HE C24

10.0 (4.0) mini HE C28

4 Water circulation system

Note. Fernox Superfloc flushing solution should be used during the flushing procedure.

models

a. With the system HOT examine all water connections for

soundness.

b. With the system still HOT, turn off the gas, water and electricity supplies to the boiler and drain down, to complete the flushing process.

c. Refill the system, adding inhibitor (see ’Water Treatment’), if required.

Vent as necessary to clear all air and, again, check for water soundness. After venting, repressurise as required.

d. Balance the system. It is suggested that, initially, all radiator handwheel valves (or TRVs if fitted) be set fully open, that all lockshield valves be set a half--- turn open.

Make minor adjustments to each radiator to achieve the same differential on all.

5 Flue system

Check the integrity of the flue outlet and air inlet system to the boiler ensuring no leaks are evident from piping joints or flue/air sampling points.

Finally, set the system controls to the users requirements.

If an optional programmer kit is fitted refer to the instructions supplied.

mini HE --- Installation & Servicing

Page 29

INSTALLATION

31 GAS CONVERSION

1 Disconnect the electrical supply. 2 Replace the burner injectors as explained in frame 43. 3 Re---assemble the burner, the front panel of the

combustion chamber and the lid of the sealed chamber. 4 Remove the service panel (frame 27 step 4). 5 Set correctly the dip--- switch ”2” to the correct position in

accordance with the following table and drawing.

Gas supply

Natural gas On

Propane Off

Position of dip--- switch 2

Natural gas L.P.G.

1 2 3

OFF

123

OFF

32 HANDING OVER

After completing the installation and commissioning of the system, the installer should hand over to the householder by the following actions:

1 Hand the User’s Instructions to the householder and

explain his or her responsibilities under the Gas Safety

(Installation and Use) Regulations 1994 and amendments

1996 or rules in force. 2 Draw attention to the Lighting Instruction label affixed to

the inside of the lower front door. 3 Explain and demonstrate the lighting and shutting down

procedures. 4 The operation of the boiler and the use and adjustment of

ALL system controls should be fully explained to the

householder, to ensure the greatest possible fuel

economy consistent with household requirements of both

heating and hot water consumption. 5 Advise the user of the precautions necessary to prevent

damage to the system and to the building, in the event of

the system remaining inoperative during frosty conditions.

6 Adjust the burner pressures according to the indications

given in frame 27.

7 Stick the self--- adhesive label (included with the

conversion kit, indicating the type of gas, and the gas pressures to which the appliance has been set) over the existing label on the bottom of the control panel.

8 Replace the service panel and the front and side panels of

the case.

9 Check the correct operation of the boiler.

INSTALLATION

6 If a programmer is fitted, draw attention to the

Programmer Instructions and hand them to the householder.

7 After installation and commissioning please complete the

Commissioning Checklist before handover to the customer. For IE, it is necessary to complete a “Declaration of Conformity” to indicate compliance to I.S. 813:2002.

8 Stress the importance of regular servicing by a CORGI

registered installer and that a comprehensive service should be carried out AT LEAST ONCE A YEAR. In IE, servicing work must be carried out by a competent person.

Emphasise to the user that the boiler may stop working if the system pressure is lowered by draining radiators to decorate behind them. In particular, explain to the user how the domestic hot water temperature varies with flow rate. This is especially important when water is drawn off while the boiler is already running for central heating.

mini HE --- Installation & Servicing

Page 30

SERVICING

33 SERVICING SCHEDULE

To ensure the continued safe and efficient operation of the appliance it is recommended that it is checked at regular intervals and serviced as necessary.

The frequency of servicing will depend upon the installation condition and usage but should be carried out at least annually.

It is the law that any service work must be carried out by a registered CORGI installer. In IE, servicing work must be carried out by a competent person.

SERVICING

1 Turn the heating controls to maximum so that the boiler

lights and remains running. Check that no other gas appliances in the house are in use or likely to be used.

2 When the boiler has settled down check the gas rate at

the meter (if the meter is of the pointer type you should time only complete revolutions of the pointer). Check the gas rate against the figures given in Table 2 for CH operation.

3 For a combination boiler, fully open a hot water tap. When

the boiler has settled down check the gas rate, as in step 2, checking the measured rate against the figures given in Table 3 for HW operation.

4 Run the boiler and check the percentage of CO and CO2

in the flue gasses at the sampling point indicated in the following drawing.

Air intake Sampling points

Note. If your meter reads CO in parts per million the figure must be divided by 10,000 to convert it to a percentage.

5 If the ratio of CO/CO2is less than ,004 and the gas rates

measured in steps 3 and 4 are close to nominal then no further action need be taken. If not, proceed to step 6.

6 Clean the main burner. 7 Clean the heat exchanger. 8 Check the injectors for blockage or damage. 9 Check that the flue terminal is unobstructed.

The servicing procedures are covered more fully in Frames 34 to 36 and MUST be carried out in sequence.

WARNING.

ALWAYS turn off the gas supply at the gas service cock, and switch off and disconnect the electricity supply to the appliance before servicing.

Switching the boiler on/off switch ‘off’ does not fully isolate the boiler.

ALWAYS test for gas soundness and carry out functional checks on reassembly.

IMPORTANT. When work is complete the boiler inner front sealing panel MUST be correctly refitted, making a good seal.

DO NOT OPERATE THE BOILER IF THE SEALlNG PANEL IS NOT FITTED.

Complete the service section in the Benchmark Commissioning Checklist.

Exhaust gas Sampling points

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SERVICING

34 REMOVAL OF OUTER AND INNER

CASING

1 Turn off the gas supply at the gas service cock and

disconnect the electricity supply.

2 Remove the screws A and lift off the boiler front panel.

3 Loosen the screws B. 4 Bring the base of the panels away from the boiler and lift

them, freeing them from the top hooks.

5 Remove the screws C and remove the boiler inner casing.

SERVICING

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SERVICING

35 BURNER REMOVAL AND CLEANING

1 Disconnect the electrical supply. 2 Remove outer and inner casing (refer to frame 34). 3 Undo the screws A and remove the fan holder bracket B

and the combustion chamber panel C.

4 Remove the screws D and the plate E.

SERVICING

6 Undo the four screws F placed at the right and left sides of

the burner and extract it.

7 Brush off any deposits that may have collected on the

burner, ensuring that the flame ports are unobstructed. Note: brushes with metallic bristles MUST NOT be used.

8 Inspect the spark and detection electrodes. Ensure they

are clean and in good condition; replace if necessary.

9 Check the spark electrodes gap is correct.

4 mm (5/32”)

5 Disconnect the electrodes leads.

36 BURNER PRESSURE CHECK

After any servicing, reference should be made to:

--- Table 2 and Table 3 (or the data plate) which quote details

of the burner pressures.

37 CLEANING THE HEAT EXCHANGER

1 Open the combustion chamber as explained in steps 1 to

3 of frame 35.

10 mm (3/8”)

Ignition

Female

10 Check that the spark and detection electrodes leads are in

good condition and renew as necessary.

If the burner pressures are incorrect ensure the inlet pressure, with the appliance running, is correct (refer Table 1).

If the burner pressures require adjustment refer to frame 27 “To adjust pressures”.

If the appliance still does not operate correctly refer to the appropriate fault finding chart.

2 Place a plastic sheet or similar beneath the heat

exchanger and remove all visible loose deposits from the heat exchanger fins, using a suitable brush.

Detection

Burner blade

Male

38 RE ---ASSEMBLY

Re --- assemble the boiler in the following order: 3 Refit the burner. 4 Reconnect the electrodes to the ignition pcb. See frame

35 for correct connectors.

5 Refit the combustion chamber panel and the fan holder

bracket.

6 Refit the inner case cover.

IMPORTANT. Ensure the boiler sealing panel is correctly fitted and that a good seal is made.

7 Refit the boiler side and front panels.

8 Turn on the gas supply at the gas service cock.

9 Reconnect the electrical supply.

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SERVICING

39 FAN AND VENTURI REMOVAL AND

CLEANING

1 Disconnect the electrical supply.

2 Remove outer and inner casing.

3 Disconnect the connectors A and the earth connection B.

4 Disconnect the pipe which connects the venturi device to

the air pressure switch.

5 Unscrew the screw C and remove the fan holder bracket

7 Check that the impeller runs freely. Clean with a soft brush

or renew as necessary. Refer to frame 51 for replacement.

Note: Always take care when handling the fan, in order to preserve the balance of the impeller.

8 Check the venturi E for cleaness.

SERVICING

9 Re---assemble in reverse order.

To correctly connect the venturi device to the air pressure switch, refer to the following illustration.

--- +

6 Remove the fan by sliding it towards left (see the arrow).

mini HE --- Installation & Servicing

Page 34

SERVICING

REPLACEMENT OF COMPONENTS

40 GENERAL

When replacing any component:

1 Isolate the electricity supply at the switched spur.

N.B. Turning the boiler “ON/OFF” switch does not isolate the live supply to the boiler.

2 Turn off the gas supply.

SERVICING

IMPORTANT. When work is complete the inner case cover must be correctly fitted, ensuring that a good seal is made.

41 SPARK AND DETECTION

ELECTRODE REPLACEMENT

1 Disconnect the electrical supply. 2 Remove outer and inner casing (refer to frame 34). 3 Open the combustion chamber and disconnect the

electrodes leads. 4 Remove the burner. Refer to frame 35. 5 Undo the screws that hold the electrodes and remove. 6 Fit new electrodes as necessary following the sequence

illustrated.

Ignition 1

Ignition 2

Detection 3

THE BOILER MUST NOT BE OPERATED IF THE INNER CASE COVER IS NOT FITTED.

If the CH and/or the DHW circuits have been emptied:

3 Open the hydraulic circuit cocks, refill / re--- pressurise

pipeworks and vent the system.

4 Test fire the boiler

5 Disconnect the filling loop.

7 Check the spark gap.

4 mm (5/32”)

10 mm (3/8”)

Ignition

Female

8 Re---assemble in reverse order. 9 Check the ignition and operation of the burner.

Detection

Burner blade

Male

42 BURNER REPLACEMENT

1 Remove the burner as explained in frame 35 2 Remove the spark and detection electrodes.

Refer to frame 41.

43 BURNER INJECTORS

REPLACEMENT

1 Remove the burner. Refer to frame 35.

2 Unscrew the injectors from the gas manifold.

3 Check that the new injectors are of the correct size and fit

it using new gaskets.

4 Re---assemble in reverse order.

5 Check the operation of the boiler.

3 Fit the electrodes on the new burner and check the spark

gap.

4 Re---assemble in reverse order.

5 Check the operation of the boiler.

Injectors

Burner

Gas manifold

mini HE --- Installation & Servicing34

Page 35

SERVICING

44 OVERHEAT THERMOSTAT

REPLACEMENT

1 Remove outer and inner casing (refer to frame 34). 2 Remove the screws A and the plate B.

45 FLUE THERMOSTAT REPLACEMENT

1 Remove outer and inner casing (refer to frame 34). 2 Disconnect the wires from the flue thermostat. 3 Unscrew and remove the thermostat probe A from the

recuperator. 4 Remove the protective cap B and unscrew the screws C

which hold the flue thermostat to the frame. 5 Remove the flue thermostat. 6 Assemble the flue thermostat carrying out the removal

operations in reverse sequence.

3 Disconnect the wiring C .

4 Remove the spring D which holds the overheat thermostat

on the pipe of the primary heat exchanger and remove it.

5 Re---assemble in reverse order.

6 Apply an adequate quantity of heat conducting

compound between the pipe and the thermostat.

A C

SERVICING

46 THERMISTOR REPLACEMENT

1 Disconnect the electrical supply. 2 Remove the front and right hand side casing panels (refer

to frame 34).

Removal of CH thermistor

3 To remove the CH thermistor close off the isolating cocks

of the CH circuit at the bottom of the boiler. 4 Release system pressure by opening the main circuit

drainage cock.

Do not release CH pressure using the pressure relief

valve. It may cause debris within the system to foul

the valve.

Removal of DHW thermistor

3 To remove the DHW thermistor close off the isolating cock

of the DHW circuit at the bottom of the boiler. 4 Empty the DHW circuit. 5 Disconnect the leads from the thermistors to be replaced

and unscrew it .

6 Screw in the new sensor, using a new gasket, reconnect

and re---assemble in reverse order.

CH thermistor DHW thermistor

Drainage cock

mini HE --- Installation & Servicing 35

Page 36

SERVICING

47 GAS VALVE ON ---OFF OPERATOR

COILS REPLACEMENT

Check

1 Disconnect the electrical supply. 2 Remove the front casing panel. 3 Disconnect the connector A and check the electrical

resistance of the coils referring to the following diagram

Upper on---off operator

SERVICING

approx. 6 400 W*

Lower on---off operator approx. 920 W*

* at ambient temperature.

4 If the resistance of either of the coils is different from the

value stated by ±10% or greater, replace the unit as

described below.

48 GAS VALVE REPLACEMENT

1 Turn off the gas supply at the gas service cock and

disconnect the electricity supply.

2 Remove the front casing panel (refer to frame 34).

Replacement

5 Remove the screw B, withdraw the coils unit C.

6 Replace it and re--- assemble in reverse order.

C D

3 Disconnect the connectors A and B.

4 Disconnect the earth wiring from the gas valve.

5 Unscrew the connectors C and remove the pipe D

6 Unscrew the inlet connector.

7 Unscrew the screws E and remove the valve.

8 Fit the new gas valve in reverse order ensuring new

gaskets are fitted and check for gas soundness.

9 Check the operation of the boiler.

49 WATER TEMPERATURE ---PRESSURE

GAUGE REPLACEMENT

1 Disconnect the electrical supply.

2 Remove the front and right hand side casing panels (refer

to frame 34).

3 Release system pressure by opening the main circuit

drainage cock A

Do not release CH pressure using the pressure relief

valve. It may cause debris within the system to foul

the valve.

4 Remove the fork B and the probe holder spring C.

5 Pull out the control panel (see frame 22).

6 Squeeze the tabs D to release the temperature---pressure

gauge E and remove it.

7 Re---assemble in reverse order.

C B

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Page 37

SERVICING

50 EXPANSION VESSEL REPLACEMENT

If the CH expansion vessel is faulty, there are 2 options:

A If it has a punctured diaphragm, but is otherwise leak free,

than it can be left in place and a new vessel added to the

return side of the system, external to the boiler, provided it

is of adequate capacity and pre--- charge pressure.

B If there is at least 400 mm (16”) clearance above the

boiler, the expansion vessel can be changed without

removing the boiler (rear exit flues will have to be

disturbed).

For option B, proceed as follows:

1 Disconnect the electrical supply.

2 Gain access to the controls area by removing the boiler

front panel (refer to frame 34).

3 Close off the isolating cocks of the CH circuit at the

bottom of the boiler.

4 Release system pressure by opening the main circuit

drainage cock.

Do not release CH pressure using the pressure relief

51 FAN REPLACEMENT

1 Disconnect the electrical supply. 2 Remove outer and inner casing. 3 Disconnect the connectors A and the earth connection B. 4 Disconnect the pipe which connects the venturi device to

the air pressure switch. 5 Unscrew the screw C and remove the fan holder bracket

valve. It may cause debris within the system to foul the valve.

5 Completely unscrew the connection A, the locknut B and

remove the expansion vessel from the top of the boiler.

SERVICING

6 Re---assemble in reverse order.

6 Remove the fan by sliding it towards left (see the arrow). 7 Re---assemble in reverse order.

Note: Always take care when handling the fan, in order to preserve the balance of the impeller.

To correctly connect the venturi device to the air pressure switch, refer to the following illustration.

--- +

52 VENTURI REPLACEMENT

1 Remove the fan (see frame 51). 2 Remove and replace the venturi device A by unscrewing

the screw B. 3 Re---assemble in reverse order.

mini HE --- Installation & Servicing 37

Page 38

53 AIR PRESSURE SWITCH

REPLACEMENT

Two different types of air pressure switch may be used in the boiler. Refer tho the following drawings in accordance with the type of air pressure switch used.

1 Disconnect the electrical supply. 2 Remove outer and inner casing as explained in frame 34. 3 Disconnect the pressure sensing pipe from the air

pressure switch. 4 Disconnect the electrical harness from the air pressure

switch.

SERVICING

5 Undo the two screws which hold the air pressure switch to

the chassis and remove it. 6 Replace the switch. 7 Re---assemble in reverse order.

To correctly connect the venturi device to the air pressure switch, refer to the illustration of frame 51 and to the following illustrations in accordance with the type of pressure switch used.

SERVICING

”H” connection

(not used)

”L” connection

COM

N.O.

”L” connection

N.C.

”H” connection

(not used)

54 PUMP REPLACEMENT COMPLETE

1 Disconnect the electrical supply.

2 Remove the front and right hand side casing panels (refer

to frame 34).

3 Release system pressure by opening the main circuit

drainage cock.

Do not release CH pressure using the pressure relief

valve. It may cause debris within the system to foul

the valve.

4 Disconnect the connector A.

5 Loosen the connector B.

6 Remove the fork C and the pipe D.

C DAB

7 Remove the fork E and the connection of the capillary

pipe of the pressure gauge.

8 Remove the locking plate F.

9 Completely loosen the connection G.

10 Unscrew the two screws H that hold the pump on the

frame

11 Remove the pump towards the front of the boiler

Re --- assemble in reverse order.

When reassembling the pump, check the correct location of the O--- ring gasket in the inlet port of the pump that seals the connection between the pump and the brass group .

If the motor only needs replacing, disconnect the connector A, unscrew the 4 screws I and remove the pump motor forwards.

IGF

mini HE --- Installation & Servicing38

Page 39

SERVICING

55 MAIN CONTROL PCB

REPLACEMENT

1 Disconnect the electrical supply.

2 Gain access to the controls area by removing the boiler

front panel and pulling the control panel (refer to frame

22).

3 Remove the screws A and remove the service panel

4 To gain access to the main control p.c.b. and the ignition

p.c.b. remove the screws B and remove the control panel

lid.

Control panel lid

Service panel

5 Remove all the wiring connected to the main control p.c.b.

To disconnect the connectors indicated, delicately flex the

hook present on one side of each socket.

7 Unscrew the four screws that hold the main control p.c.b.

on to the control panel.

8 Remove it by lifting its rear edge and freeing it from any of

the wiring.

9 Re---assemble in reverse order.

Setting jumpers

Two setting jumpers C are fitted on the main control p.c.b.

Refer to the following illustration for the position of the jumpers when the main control p.c.b. is fitted.

The numbers refer to the marking printed on the circuit board.

1 2 3 4 5 6 7 8 9

Important

When re---assembling the electronic control p.c.b.:

10 Fit the p.c.b. into the control panel by first inserting the

front lower edge under the control knob shafts. Lower the rear edge and ensure that no wiring is trapped beneath.

11 Insert the spindles in the control panel knobs until the

notch D reaches the potentiometer edge. It is not necessary to force them in the knob.

12 While tightening the screws that fix the main control p.c.b.

on the control panel, keep the p.c.b. towards the control panel fascia making sure of the contact between the boiler reset button E and the tab F. Replace the wiring connections ensuring correct engagement in the sockets

SERVICING

6 Remove the spindles of the CH and DHW temperature

adjustment knobs by delicately pulling them with pliers in

the direction shown by the arrow.

D E F

Attention

After installing the main control p.c.b.:

13 Make sure the CH (

adjustment knobs can move freely for the complete range. If not, remove the spindle again as described at step NO TAG, turn the knob half a turn and re---insert the spindle.

14 Operate the boiler and close the gas inlet cock so that the

boiler goes into the safety lock---out state. Verify the correct operation of the boiler reset button by pressing and releasing it.

15 Open the gas inlet cock and check the boiler operates

correctly.

) and DHW ( ) temperature

mini HE --- Installation & Servicing 39

Page 40

SERVICING

56 IGNITION PCB REPLACEMENT

1 Gain access to the parts located inside the control panel

as explained in the the frame 55. 2 Remove all the wiring connected to the ignition p.c.b.

To disconnect the connectors indicated, delicately flex the

hook present on one side of each socket. 3 Unscrew the two screws A that hold the ignition p.c.b. on

the panel and remove the component. 4 Re---assemble in reverse order. 5 Check the boiler operates correctly.

SERVICING

57 CH FLOW SWITCH REPLACEMENT

1 Disconnect the electrical supply.

2 Remove the front casing panel.

3 Remove the fork A.

4 Open the box B and disconnect the switch.

5 Re---assemble in reverse order.

Refer to the following illustration for the correct wiring connectors on the switch

N.O.

58 CH FLOW SWITCH MEMBRANE

REPLACEMENT

1 Disconnect the electrical supply. 2 Remove front casing panel (refer to frame 34). 3 Close off the isolating cocks of the CH circuit at the

bottom of the boiler. 4 Release system pressure by opening the main circuit

drainage cock.

Do not release CH pressure using the pressure relief

valve. It may cause debris within the system to foul

the valve.

5 Remove the CH circuit flow switch (see frame 57). 6 Unscrew the four screws A, open the hydraulic operator

and remove the membrane B. 7 Re---assemble in reverse order.

When assembling the membrane, ensure to place the

do not use

Looking through the switch box B it is possible to verify the position of the spindle C

Boiler OFF Pump operating

concave side of the membrane towards the actuator plate C and locate the reference hole in the membrane over the pressure transfer nipple D.

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Page 41

SERVICING

59 DHW FLOW SWITCH REPLACEMENT

1 Disconnect the electrical supply. 2 Remove the front panel of the case (refer to frame 34). 3 Disconnect the connector A and remove the sensor by

pulling it towards the front of the boiler (the sensor is held

in place by means of a spring). 4 Replace the sensor and re--- assemble in reverse order

60 DHW FILTER AND FLOW LIMITER

REPLACEMENT

1 Disconnect the electrical supply. 2 Remove the front panel of the case and empty the DHW

circuit. 3 Remove the flow switch A (see frame 59). 4 Remove the gas valve (see frame 48). 5 Unscrew the plug B and extract the flow switch group. 6 To remove the filter C from the flow switch group separate

the body D from the plug B by unscrewing it. 7 Re---assemble in reverse order.

Return manifold

Spring

Float

Magnetic ring

B --- plug

A --- flow switch

Attention: the magnetic ring has a magnetic polarity and must be correctly coupled with the spindle of the float.

To determine the correct orientation of the ring proceed as follows:

1 Set the function selector of the boiler in stand---by mode.

Threaded ringThreaded ring

Flow limiter

Spring seat

D --- body

C --- filter

2 Restore the mains electricity supply to the boiler.

Warning --- ensure that all the electric parts and wiring are dry and do not touch other electric parts during the following operations.

3 Hold the flow switch sensor and bring the ring in contact

with the sensor as illustrated in the following drawing.

4 Observe if the lamp fitted in the sensor body is lit. If not

reverse the ring and repeat the previous operation.

5 Fit the ring on the spindle of the float in the way that lights

the lamp. Ensure filter is correctly positioned and that plug “B” and the threaded ring are screwed tight into the body “D”.

6 Isolate the boiler from the mains electricity supply and

reassemble the parts following the removing sequence in reverse order.

Flow limiter

The mini HE C24 model is factory fitted with a 10 litre/min. flow limiter.

The mini HE C28 model is factory fitted with a 12 litre/min. flow limiter.

Table 8

Nominal flow rate (litres/min)

10 Yellow

12 Brown

1 Disconnect the electrical supply. 2 Remove the front panel of the case and empty the DHW

circuit. 3 Remove the flow switch A (see frame 59). 4 Remove the gas valve (see frame 48). 5 Remove the flow switch group (see frame 60 above) 6 Unscrew the threaded ring and extract the flow limiter.

7 Fit the correct colour coded limiter (see Table 8 above)

and screw the threaded ring tight into the body ’D’. 8 Re---assemble in reverse order.

Colour

SERVICING

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SERVICING

61 PRIMARY HEAT EXCHANGER

REPLACEMENT

1 Disconnect the electrical supply.

2 Remove outer and inner casing as explained in frame 34.

3 Close off the isolating cocks of the CH circuit at the

bottom of the boiler.

4 Release system pressure by opening the main circuit

drainage cock. Do not release CH pressure using the

SERVICING

pressure relief valve. It may cause debris within the system to foul the valve.

5 Remove the combustion chamber panel A by unscrewing

the screws B and removing the fan holder bracket C.

6 Remove the screw D and the plate E.

7 Loosen the connection F and slightly move the pipe G

upwards.

8 Remove the clip H and the safety thermostat I. It is not

necessary to disconnect it from the wiring.

9 Completely unscrew the connection J and move the pipe

K downwards freeing it from the heat exchanger connection.

10 Remove the clip L.

11 Move the pipe M upwards freeing it from the connection

and rotate towards right.

Fit the clip H with the arrow pointing upwards as illustrated in the drawing.

Do not force the connection F when tighting it.

K L E

12 Remove the heat exchanger by sliding it forwards.

13 Re --- assemble in reverse order.

62 RECUPERATOR REPLACEMENT

1 Disconnect the electrical supply. 2 Remove outer and inner casing as explained in frame 34. 3 Close off the isolating cocks of the CH circuit at the

bottom of the boiler.

4 Release system pressure by opening the main circuit

drainage cock.

Do not release CH pressure using the pressure relief valve. It may cause debris within the system to foul the valve.

5 Remove the fan A (see frame 51) and the air pressure

switch B (see frame 53).

6 Remove the flue thermostat C (see frame 45) 7 Completely loosen the connection D and slightly move the

pipe E upwards.

8 Remove the clip F and move the pipe G downwards

freeing it from the connection, then turn it towards right.

9 Using pliers, remove the spring H moving it downwards

and disconnect the rubber pipe I.

10 Remove the bracket J by unscrewing the screws that hold

it on the frame.

11 Rotate the recuperator K as indicated by the arrow and

remove it towards the front of the boiler. 12 Remove the clip L and the pipe E. 13 Reassemble the recuperator carrying out the removal

operations in reverse order.

mini HE --- Installation & Servicing42

Page 43

SERVICING

After reassembling ensure that the fan ---exchanger and exchanger---elbow gaskets are correctly mounted and ensure a good sealing.

SERVICING

mini HE --- Installation & Servicing 43

Page 44

SERVICING

63 DHW HEAT EXCHANGER

REPLACEMENT

1 Disconnect the electrical supply. 2 Remove outer casing (refer to frame 34). 3 Close the isolating cocks of the CH circuit and DHW

supply at the bottom of the boiler. 4 Release system pressure by opening the main circuit

drainage cock.

Do not release CH pressure using the pressure relief

valve. It may cause debris within the system to foul

the valve.

SERVICING

5 Release the pressure of the DHW circuit by opening a hot

tap. 6 Remove the diverter valve actuator (see frame 64). 7 Completely unscrew the two Allen key screws A which

hold the exchanger to the brass groups.

8 Move the exchanger towards the rear of the boiler and

extract it.

9 Re---assemble in the reverse order.

Attention. When reassembling the exchanger be sure to put the off center location/securing pin indicated towards the left side of the boiler.

64 DIVERTER VALVE ACTUATOR

REPLACEMENT

1 Disconnect the electrical supply. 2 Remove front casing panel (refer to frame 34).. 3 Disconnect the connectors A. 4 Remove the fixing spring B and remove the actuator C.

Re --- assemble in reverse order.

When reassembling the actuator, refer to the wiring diagram in frame 23 for the correct wiring connection.

B AC

mini HE --- Installation & Servicing44

Page 45

SERVICING

65 DIVERTER VALVE INTERNAL PARTS

REPLACEMENT

1 Disconnect the electrical supply.

2 Remove front and left hand casing panels (refer to frame

34).

3 Close the isolating cocks of the CH circuit and DHW

supply at the bottom of the boiler.

4 Release system pressure by opening the main circuit

drainage cock.

Do not release CH pressure using the pressure relief

valve. It may cause debris within the system to foul

the valve.

5 Release the pressure of the DHW circuit by opening a hot

tap.

6 Remove the diverter valve actuator (see frame 64).

7 Remove the fork D and remove the primary circuit flow

switch E.

8 Disconnect both CH and DHW thermistors F.

9 Unscrew the connector G, disconnect the CH flow and

DHW outlet isolator valves.

(rear view) 13 Refer to the following exploded view to remove the

internal parts of the three way diverter valve.

SERVICING

F F

10 Remove the DHW heat exchanger (see frame 63).

11 Remove the fork H and move away the pipe I.

12 Unscrew the screw J and remove the diverter (flow)

group.

66 PROGRAMMER REPLACEMENT

(if fitted)

1 Disconnect the electrical supply.

2 Gain access to the main control p.c.b. (steps 1 to 4 of

frame 55).

3 Disconnect the wiring at the programmer.

14 Re --- assemble in reverse order.

4 Squeeze the hooks that hold the programmer on the

control panel fascia and withdraw the faulty programmer.

5 Re---assemble in reverse order.

When reassembling the new programmer, refer to the wiring diagram in frame 23 for the correct wiring connection.

6 Replace the panels and check the operation of the new

programmer.

mini HE --- Installation & Servicing 45

Page 46

67 CH DRAIN COCK REPLACEMENT

1 Disconnect the electrical supply

2 Remove front and right hand casing panels

(refer to frame 34).

3 Close off the isolating cocks of the CH circuit at the

bottom of the boiler.

4 Release system pressure by opening the main circuit

drainage cock.

Do not release CH pressure using the pressure relief

valve. It may cause debris within the system to foul

SERVICING

the valve.

5 Remove the CH drain cock A from the return body.

6 Re---assemble in reverse order.

68 CONDENSATE TRAP REPLACEMENT

1 Disconnect the electrical supply

2 Remove front and right hand casing panels

(refer to frame 34).

3 Disconnect the trap from the draining pipe.

4 Using pliers, remove the spring A moving it up-

wards.

SERVICING

5 Remove the nut B and lower the trap.

6 Disconnect the wirings from the trap.

7 Reassemble carrying out the removal operations

in reverse order.

mini HE --- Installation & Servicing46

Page 47

FAULT FINDING

(functioncontrolinposition)

(functioncontrolinorposition)

---Lackofburnerignition

69 MAIN CONTROL P.C.B.

OPTICAL INFORMATION

The main control p.c.b. is provided with three lamps (L.E.D. indicators) A that give optical information during the normal operation of the boiler or for service and fault fiinding purpose.

Normal operation

The green lamp on the left is directly visible on the control panel fascia and it gives information during the normal operation of the boiler. The other two lamps are normally switched off.

The following table gives the relationship between the visible lamp indication and its meaning.

Boiler in stand--- by condition. (function control in position).

Anti--- freeze system active.

A short pulse every 4 seconds

Boiler ON condition (function control in or

1 second ON 1 second OFF

Faulty boiler or irregular operation as:

Very fast pulses (4 per second)

--- Empty primary circuit

--- No primary circuit flow

--- Lack of burner ignition

--- Excessive temperature in the primary circuit.

--- Dip --- switch 3 left in the OFF position

--- Faulty temperature probe

The following table gives a summary of the relationship between each of the possible lamp combinations and their meaning.

Normally operating boiler

CH operation

DHW operation

Frost protect operation

DHW operation Excessive temperature on primary circuit

Faulty CH temperature probe NTC

Faulty DHW temperature probe NTC

Faulty primary circuit (no water or absence of flow)

Lack of burner ignition (no ignition signal from the full seqence ignition device)

Ignition gas pressure adjustment

Minimum gas pressure adjustment

Lamp

OFF

Lamp

Flashing lamp, alone

or simultaneously

with an other lamp.

Flashing lamp,

alternate with

another lamp.

FAULT FINDING

70 DIVERTER VALVE ACTUATOR

SPINDLE POSITION

To remove the diverter valve actuator refer to frame 64.

The following illustrations indicate the relationship between the electric command coming from the main control p.c.b. and the position of the brass spindle when the boiler operates in either DHW mode or CH mode.

In both figures the relationship between the position of the actuator and the resistance of the motor windings (the motor must be disconnected from the wiring) is also given.

Spindle

visible

bkbnbu

0 V

CH mode DHW mode

Open circuit

9,4 Kohm

bn = brown

230 V

bu = blue bk = black

Spindle fully

retracted

bkbnbu

230 V

0 V

9,4 Kohm

Open circuit

mini HE --- Installation & Servicing

Page 48

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Page 49

Continued from page

48 of fault finding

FAULT FINDING

With the boiler and

heating circuit warm

does the burner

pressure reduce if the

heating temperature setting is reduced to

minimum?

yes

When a DHW tap is

opened and the DHW

temperature is set to

maximum, does the water become hot?

yes

Is there between 0V dc

and 16V dc at the Grey

and Black connections

on the modulating coil?

(0=min, 16=max)

yes

Repair faulty gas

valve

no no

Is the p.c.b. jumper

in position 8

(Refer to frame 55)

yes

Is the red LED

illuminated on DHW

flow sensor?

yes

Is there 230V

ac between

Blue and

Black at the

3---way valve

connection?

yes

no no

Is the continuity of the

modulator harness

O.K?

yes

Repair faulty PCB

Connect jumper in

position 8.

no no no

Is the

continuity of

the 3---way

valve

harness

O.K?

yes

Is there 5V dc between

Red and Blue on

connecting harness?

Repair or

replace

faulty

wiring

yes

Repair or replace

faulty wiring

Is tharness

continuity O.K?

yes

Repair faulty

PCB #1

Repair or

replace

faulty wiring

FAULT FINDING

Continued on page

54 of fault finding

Remove the

motor

assembly, with

230V at the

connections is

the spindle fully

retracted? Refer

to frame 70.

yes

Replace

faulty valve

body

assembly

Repair

faulty

PCB #1

Replace

faulty motor

assembly

Replace the

sensor. Is

red LED

illuminated?

yes

Faulty

sensor

now

replaced

no no

Dismantle the DHW detector

valve and clean.

Refer to frame 60.

Reassemble.

Does the DHW

water become

hot?

yes

Repair or

replace

faulty DHW

detector

valve

mini HE --- Installation & Servicing

Page 50

Continued from page 48 of fault

finding. Is the green

LED on front fascia

flashing 4 times per

second?

FAULT FINDING

Access the 4 dip

switches on p.c.b. #1.

Move the #1 dip switch off’ then ’on’. This activates p.c.b.

service mode. Refer to

fault code frame 69. Is

LED 1 flashing with

LED 2 on ?

FAULT FINDING

yes

Is the heating circuit

pressurised to at least 1 bar and fully vented

yes

Remove the pump

nut. Does the pump

rotate freely when

yes

When the pump

runs does the

spindle of the water

flow detector extend to operate the micro switch? Refer to frame 57.

yes

Is there continuity

between C and NO

contacts on micro

switch when the

switch is operated?

of air?

turned)

Are LED2 and LED 3

flashing?

Check resistance of

CH thermistor. Is it

between 12 kW and

1.5 kW ?

yes

Repair or replace

faulty wiring

Re--- pressurise

system and vent

Replace faulty pump

Replace faulty

diaphragm and clean

housing of debris, if any.

refer to frame 58.

Replace faulty micro

switch

no no

Are LED2 flashing

LED 3 on?

yes

no no

Replace faulty

thermistor

Check resistance of

DHW thermistor. Is

it between 12 kW

and 1.5 kW ?

yes

Repair or replace

faulty wiring

Continued on page

51 of fault finding

Replace faulty

thermistor

yes

Is the continuity of

the micro switch

harness O.K?

yes

Replace faulty PCB

Repair or replace

faulty wiring

mini HE --- Installation & Servicing

Page 51

FAULT FINDING

Continued from page 50

of fault finding

Are LED 1 and LED 3

flashing with LED 2

on, plus LED 4 on the

Is there > 17 mbar at

the gas valve inlet?

Press reset button. Is

yes

there 230V across the

Black and Blue gas

valve connection

during ignition?

facia on?

yes

nono

Rectify gas supply

fault.

no no no no

Is there

230V at

Black and

Blue at

gas valve

harness

connector

on PCB

#2?

yes

Repair or

replace

faulty wiring

Is there 230V

at pin 101

Brown on

connecting

harness at

PCB #2?

yes yes

Is fuse continuity O.K. on PCB #2?

yes

Continued on

page 53 of

fault finding

PCB

Replace faulty PCB #2

Is there 230V

at pin 11

Brown on

PCB

connecting

harness at

PCB #1?

Repair or replace faulty wiring

Replace

faulty PCB

Replace

fuse

FAULT FINDING

Is there a burner

pressure during

ignition period?

yes

Is there ignition at the

burner?

yes

Continued on page 52 of

fault finding

Has the main overheat

no no

thermostat operated?

(Check continuity)

yes

Allow boiler to cool

and press re ---set

no no no no

Is a spark

visible at the

burner during

ignition?

yes

Is the ignition burner

pressure correct? Refer

to frame 27.

yes

Ensure the ignition electrode position and spark gaps are correct.

Are the ignition

Has the flue thermostat operated? (Press the thermostat

reset button and/or

Check continuity)

yes

Allow boiler to cool

and press re ---set

leads

disconnected

or damaged

and sparking

to earth?

yes

Replace

faulty

electrode

assy. Make

connection.

Adjust ignition burner

pressure

Rectify or replace. Refer to frame 41.

Are the ignition leads correctly

connected to

PCB #2?

yes

Replace

faulty PCB #2

Is there continuity of overheat thermostat

wiring at PCB

connection?

Replace faulty gas

yes

valve

Rectify

faulty

connection

Repair or replace

damaged wiring

mini HE --- Installation & Servicing

Page 52

Continued from page 51

of fault finding

FAULT FINDING

Does the burner

remain alight?

yes

no no

Is the position of the

detection electrode correct, and electrode undamaged? Refer to

frame 41.

yes

Is the resistance of the

detection electrode

assembly < 5W from

tip to connector ?

yes

Is the polarity of

the mains correct?

yes

Is the condense

freely discharged

through the

condensate trap

and pipework?

yes

Replace faulty PCB #2

Rectify electrode

position or replace

faulty electrode.

Is the lead

connected ?

yes

Replace faulty

detection lead assy.

Rectify wiring fault

Check the

condensate trap

and discharge

pipework for

cleaness

Connect lead

correctly

Is the burner pressure

within min and max

value* with the boiler

running?

yes

Adjust burner pressure.

Refer to frame 27.

Refer back to page 48 of

fault finding to continue.

* see Table 2 at page 4 for the correct value

mini HE --- Installation & Servicing

Page 53

FAULT FINDING

Continued from page 51 of fault

finding

Is the fan running?

yes

Is LED 1 on and LED

2 flashing?

Is dip---switch # 3 in

the off position?

Refer to frame 27.

yes

Switch to on position.

no no no

Is there 230V at the

fan connections?

yes

Replace faulty fan.

no no

Replace faulty PCB #1

Is there continuity

between NC and C at

the Air Pressure

Switch?

yes

Is there continuity of

the Air Pressure

Switch harness?

yes

no no

Is there 230V at

pin 101 PCB # 2?

yes yes

Is LED 1 flashing and

LED 2 and LED 3 on?

yesyes

Is dip---switch # 3 in

the off position?

Refer to frame 27.

yes

Switch to on position.

Replace faulty Air

Pressure Switch.

Repair or replace

faulty wiring.

Are the connections

between PCB # 1 and

PCB # 2 O.K?

Replace faulty PCB #1

Repair or replace

wiring.

FAULT FINDING

Is there continuity

across C and NO on

the Air Pressure

Switch?

yes

Is the Air Pressure

Switch harness

continuity O.K?

yes

Is the burner on?

yes

Repair or replace

faulty flame detection

signal connection

harness. Refer to

frame 41.

no no

Are the sensing pipes

undamaged and

connected?

yes

Is the flue clear and

venturi O.K?

yes

Replace faulty Air

Pressure Switch

Repair or replace

faulty wiring.

Replace faulty PCB #2

Replace faulty PCB #2 Replace faulty PCB #1

Replace sensing

pipes.

Clear flue

Repair or replace

mini HE --- Installation & Servicing

Page 54

Continued from

page 49

Is there a temperature rise

of 35 ° C across the DHW

circuit at:

10.0 L/min 24 kW model

11.6 L/min 28 kW model

FAULT FINDING

no no no

Is there max burner pressure* when the

boiler first lights?

yes

Is there > 17 mbar

gas pressure at the

gas inlet?

yes

Rectify gas supply

fault.

FAULT FINDING

yes

no no no

With the DHW hot

does the burner

pressure modulate if

the DHW temperature

setting is reduced to

minimum?

yes yes

Is the maximum water

flow correct

10.0 L/min 24 kW model

12.0 L/min 28 kW model

Is there between 0V dc

and 16V dc at the

Grey and Black

connections on the

modulating coil?

(0=min, 16=max)

Adjust the max setting

on the gas valve. Refer

to frame 27. Check that

max burner pressure*

can be achieved.

Is the cold water supply

adequate? refer to frame

6 and Table 1 at page 4.

yes

Check the DHW inlet

filter. Remove debris

and clean or replace

filter.

Is the continuity of the

modulator harness

O.K?

yes

nono

Rectify water supply

fault.

Repair or replace

faulty wiring.

Boiler Operating

Correctly

Replace faulty gas

valve.

Replace faulty PCB

* see Table 2 at page 4 for the correct value

mini HE --- Installation & Servicing

Page 55

The following are parts commonly required as replacements, due to damage or expendability. The failure or absence is likely to affect the safety and/or performance of this appliance.

The list is extracted from the British Gas List of Parts which contains all available spare parts.

The full list is held by British Gas, Caradon Plumbing Ltd. distributors and merchants.

When ordering spares please quote:

1 Boiler model (see Data Plate) 2 Appliance G.C. number (see Data Plate)

3 Description 4 Quantity 5 Product No.

Key No.

1 173---148 Burner (mod. mini HE C24) 1 075427

2 Main heat exchanger + ’O’ rings (mod. mini HE C24) 1 173991

3 Recuperator 1 173993

4 169---069 Injectors for natural gas (mod. mini HE C24) 12 075692

5 H21---048 Fan (mod. mini HE C24) 1 173983

6 E90--- 627 Gas valve + gaskets 1 172611

7 169---127 Air pressure switch (mod. mini HE C24) 1 173236

8 E83--- 013 Safety valve 1 172494

9 Electronic regulation p.c.b. 1 174017

10 E83 --- 142 Full sequence ignition device 1 172548

11 E00 --- 684 Primary circuit flow switch 1 075419

12 E83 --- 082 DHW flow switch (mod. mini HE C24) 1 172503

13 E00 --- 688 Main. flow switch membrane 1 075421

14 E83 --- 101 Overheat thermostat 1 172512

15 E57 --- 048 DHW heat exchanger + ’O’ rings (mod. mini HE C24) 1 075460

16 H20 --- 986 Automatic air purger valve 1 173813

17 Pump + ’O’ rings 1 174004

18 E83 --- 145 Temperature--- pressure gauge 1 172551

19 H21 --- 064 Flue thermostat 1 173985

20 E83 --- 086 Three way diverter valve (electric actuator) 1 172505

21 H21 --- 060 Sealed chamber gaskets kit 1 173986

22 E83 --- 081 Magnetic flow switch and filter 1 172502

23 E83 --- 127 Ignition electrode --- left 1 172533

24 E83 --- 126 Ignition electrode --- right 1 172532

25 E83 --- 122 Detection electrode 1 172531

26 E69 --- 243 Window (glass + rubber frame) 1 170977

27 169 --- 141 1/2” flat gasket 3 075514

28 169 --- 033 3/4” flat gasket 4 075415

29 169 --- 083 Fuse 1,6 A T 1 172562

30 164 --- 026 Temperature probe (main or DHW circuit) 1 172496

31 H21 --- 052 Side case panel 2 173987

G.C. No Description No. Off/

Boiler

173--- 149 Burner (mod. mini HE C28) 1 075535

Main heat exchanger + ’O’ rings (mod. mini HE C28) 1 173992

Injectors for natural gas (mod. mini HE C28) 14

E01---156 Injectors for LPG (mod. mini HE C24) 12 173982

Injectors for LPG (mod. mini HE C28) 14

H21---049 Fan (mod. mini HE C28) 1 173984

H08---605 Air pressure switch (mod. mini HE C28) 1 173136

E57---049 DHW heat exchanger + ’O’ rings (mod. mini HE C28) 1 075540

Product No.

mini HE --- Installation & Servicing

Page 56

Control panel door 1 173988

33 Front case panel 1 173989

7 8

23 25

1511

1713

26 27 28

29 30

mini HE --- Installation & Servicing

Page 57

INSTALLER

NOTIFICATION

GUIDELINES

IT IS A REQUIREMENT OF CORGI MEMBERSHIP

TO REGISTER EVERY GAS APPLIANCE

Install and commission

this appliance to

manufacturers’ instructions

Complete the

Benchmark Checklist

In addition a change to Building Regulations (England and

Wales) requires the installer to notify

when installing a heating appliance, as from 1st April 2005.

Competent Person’s

SELF CERTIFICATION SCHEME

If you notify via CORGI Scheme, CORGI will then notify the Building Control (LABC) who relevant Local

Authority Building Control (LABC)

scheme on members behalf

Scheme members only:

Call CORGI on 0870 88 88 777 or

log onto:

www.corgi---notify.com

within 10 days

You must ensure that the

notification number issued by

CORGI is written onto the

Benchmark Checklist

Choose Buildings

Regulations

notification route

BUILDING CONTROL

Contact your relevant Local

Authority Building Control (LABC)

who will arrange an inspection or

contact a government approved

inspector

LABC will record the data and will

issue a certificate of compliance

CORGI will record the data and will

send a certificate of compliance to

the property

mini HE --- Installation & Servicing

IT IS A CONDITION OF THE

MANUFACTURERS WARRANTY

THAT THE BENCHMARK

COMMISSIONING CHECKLIST IS

FULLY COMPLETED AND LEFT

WITH THE APPLIANCE

Page 58

BENCHMARK No.

GAS BOILER COMMISSIONING CHECKLIST

BOILER SERIAL No. NOTIFICATION No.

To comply with the Building Regulations, each section must have a tick in one or other of the boxesCONTROLS

TIME & TEMPERATURE CONTROL TO HEATING TIME & TEMPERATURE CONTROL TO HOT WATER HEATING ZONE VALVES HOT WATERZONE VALVES THERMOSTATIC RADIATORVALVES AUTOMATICBYPASSTO SYSTEM

ROOM T/STAT & PROGRAMMER/TIMER

CYLINDER T/STAT& PROGRAMMER/TIMER

FITTED FITTED NOT REQUIRED FITTED FITTED NOT REQUIRED

PROGRAMMABLE ROOMSTAT

FOR ALL BOILERS CONFIRM THE FOLLOWING

THE SYSTEM HAS BEEN FLUSHED IN ACCORDANCE WITH THE BOILER MANUFACTURER’S INSTRUCTIONS ? THE SYSTEM CLEANER USED THE INHIBITOR USED

FOR THE CENTRAL HEATING MODE, MEASURE & RECORD

GAS RATE BURNER OPERATING PRESSURE (IF APPLICABLE) CENTRAL HEATING FLOW TEMPERATURE CENTRAL HEATING RETURN TEMPERATURE

FOR COMBINATION BOILERS ONLY

COMBI BOILER

NOT REQUIRED

m3/hr ft/hr N/A mbar

°C °C

HAS A WATER SCALE REDUCER BEEN FITTED? WHATTYPE OF SCALE REDUCER HAS BEEN FITTED?

YES NO

FOR THE DOMESTIC HOT WATER MODE, MEASURE & RECORD

GAS RATE MAXIMUMBURNER OPERATING PRESSURE (IF APPLICABLE) COLD WATERINLET TEMPERATURE HOT WATEROUTLET TEMPERATURE WATER FLOW RATE lts/min

m3/hr ft/hr N/A mbar

FOR CONDENSING BOILERS ONLY CONFIRM THE FOLLOWING

THE CONDENSATE DRAIN HAS BEEN INSTALLED IN ACCORDANCE WITH THE MANUFACTURER’S INSTRUCTIONS?

YES

FOR ALL INSTALLATIONS CONFIRM THE FOLLOWING

THE HEATING AND HOT WATER SYSTEM COMPLIES WITH PARTS4 & 7 OF THE BUILDING REGULATIONS

THE APPLIANCE AND ASSOCIATED EQUIPMENT HAS BEEN INSTALLED AND COMMISSIONED IN ACCORDANCE WITH THE MANUFACTURER’S INSTRUCTIONS

IF REQUIRED BY THE MANUFACTURER, HAVE YOU RECORDED A CO/CO2RATIOREADING? CO/CO2RATIOYESN/A THE OPERATION OF THE APPLIANCE AND SYSTEM

CONTROLS HAVE BEEN DEMONSTRATED TOTHE CUSTOMER

°C °C

THE MANUFACTURER’S LITERATUREHAS BEEN LEFT WITH THE CUSTOMER

COMMISSIONING ENG’S NAME

PRINT CORGI ID No. SIGN

DATE

Page 59

SERVICE INTERVAL RECORD

Itisrecommendedthatyour heatingsystem is serviced regularly

and thatyou completetheappropriateService IntervalRecord Below.

Service Provider.Before completing the appropriate Service Interval Record below,please ensure you have carried out the service

as described in the boiler manufacturer’s instructions.Always use themanufacturer’s specifiedspare part when replacing all controls

SERVICE 1

ENGINEER NAME COMPANYNAME TEL No. CORGI ID CARD SERIAL No. COMMENTS

SIGNATURE

SERVICE 3

ENGINEER NAME COMPANYNAME TEL No. CORGI ID CARD SERIAL No. COMMENTS

SIGNATURE

SERVICE 5

ENGINEER NAME COMPANYNAME TEL No. CORGI ID CARD SERIAL No. COMMENTS

DATE

SERVICE 2

ENGINEER NAME COMPANYNAME TEL No. CORGI ID CARD SERIAL No. COMMENTS

SIGNATURE

SERVICE 4

ENGINEER NAME COMPANYNAME TEL No. CORGI ID CARD SERIAL No. COMMENTS

SIGNATURE

SERVICE 6

ENGINEER NAME COMPANYNAME TEL No. CORGI ID CARD SERIAL No. COMMENTS

DATE

SIGNATURE

SERVICE 7

ENGINEER NAME COMPANYNAME TEL No. CORGI ID CARD SERIAL No. COMMENTS

SIGNATURE

SERVICE 9

ENGINEER NAME COMPANYNAME TEL No. CORGI ID CARD SERIAL No. COMMENTS

SIGNATURE

DATE

SIGNATURE

SERVICE 8

ENGINEER NAME COMPANYNAME TEL No. CORGI ID CARD SERIAL No. COMMENTS

SIGNATURE

SERVICE 10

ENGINEER NAME COMPANYNAME TEL No. CORGI ID CARD SERIAL No. COMMENTS

SIGNATURE

DATE

Page 60

Technical Training

The Ideal Boilers Technical Training Centre offers a series of first class training courses for domestic, commercial and industrial heating installers engineers and system specifiers.

For details of courses please ring: 01482 498 432. . . . . . .

commissioning & servicing of central heating systems

the code of practice for the installation

Ideal boilers

P.O. Box 103, National Ave, Kingston upon Hull HU5 4JN. Telephone: 01482 492 251 Fax: 01482 448 858. Registration No. London 322 137

Caradon Ideal Limited pursues a policy of continuing improvement in the design and performance of its products. The right is therefore reserved to vary specification without notice.

Ideal Installer/Technical Helpline: 01482 498 663

www.idealboilers.com