ideal Mini C24 User guide

Download

installation and servicing

mini

Your Ideal installation and servicing guide

For details of document amendments, refer to page 3

Model

Serial No.

C24,C28,C32 S24,S28

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 requir e. Do not use reconditioned or copy parts that have not been clearly authorised by Ideal Boilers

17962.1062.4 4307 64A4 GB

*1796210624*

For the v e ry latest co py o f lite r a t u re for specific at ion purpo ses please visit our w e b sit e www .idealbo ilers.co m wher e yo u will be able to download the relevant informatio n in pdf format.

Mini --- Installation & Servicing

DOCUMENT AMENDMENTS

Relevant Installation changes implemented in this book from book reference.................17962.1062.4 2007

F Further guidance added to Important Notes section of User Guide

Ideal Stelrad Group reserve the right to vary specification without notice

Mini Installation & Servicing

GENERAL

Ta b l e 1 --- B o i l e r D a t a

Mini C24 Mini C28 Mini C32 Mini S24 Mini S28

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)

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 150 170 180 150 170

External fuse rating 3A

Internal fuse rating 3.15 AF

Water content --- CH litre (gal.) 1.0 (0.22) 1.1 (0.242) 1.0 (0.22) 1.1 (0.242)

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

Dry weight kg (lb.) 37 (81.6) 39 (86.0) 39 (86.0) 36 (79.4) 38 (83.8)

Size: Height / Width / Depth mm (in.) 703 (27 11/16”) / 400 (15 3/4”) / 310 (12 3/16”)

Lift weight kg (lb.) 35.5 (78.4) 36.5 (80.6) 36.5 (80.6) 34.5 (76.2) 35.5 (78.4)

bar (lb/in2) 2.5 (36.3)

Ta b l e 2 --- P e r f o r m a n c e D a t a --- C e n t r a l H e a t i n g

Mini C24 Mini S24

Max Min Max Min Max Min

Burner pressure (Hot) G20

Input based on nett CV kW

Input based on gross CV kW

Output kW

Gas consumption (Hot) G20

Seasonal efficiency* (SEDBUK)

NOx classification Class 3 Class 2 Class 3

G31

mbar (in.w.g.)

(btu/h)

l/s (ft3/h) l/s

11.7 (4.7)

35.7 (14.3)

26.60

(90 759)

29.52

(100 732)

24.30

(82 912)

0.763 (97.0)

0.309

1.8 (0.7)

6.1 (2.4)

11.00

(37 532)

12.21

(41 656)

9.10

(31 049)

0.315 (40.1)

0.128

Band D

78.2

*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.

Ta b l e 3 --- P e r f o r m a n c e D a t a --- D o m e s t i c H o t W a t e r

Mini C24 Mini C28 Mini C32

Burner pressure (Hot) G20

Input based on nett CV kW (btu/h) 26.60 (90 759) 31.10 (106 113) 35.20 (120 102)

Input based on gross CV kW (btu/h) 29.52 (100 732) 34.52 (117 773) 39.07 (133 306)

Output kW (btu/h) 24.30 (82 912) 28.40 (96 901) 32.00 (109 184)

Gas consumption (Hot) G20

Flow 35 ˚Ctemp.rise l/m (gpm) 10.0 (2.2) 11.6 (2.6) 13.1 (2.9)

Domestic hot water specific rate

Note: the gas consumption is calculated using a calorific value of 38.7 MJ/m

Btu/ft

) nett.

(1038 Btu/ft3) gross or 34.9 MJ/m3(935

mbar

G31

(in.w.g.)

l/s (ft3/h)

G31

l/s

l/m (gpm) 11.6 (2.6) 13.6 (3.0) 15.3 (3.4)

11.7 (4.7)

35.7 (14.3)

0.763 (97.0)

0.309

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

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

b. FOR FT

/H --- divide the gross heat input (Btu/h) by the

gross C.V. of the gas (Btu/ft

)

G20 20mbar, G31 37mbar, 22 mm copper

2H3P

Mini C28 Mini S28

11.7 (4.7)

35.7 (14.3)

31.10

(106 113)

34.52

(117 773)

28.40

(96 901)

0.892 (113.5)

0.361

Maximum

11.7 (4.7)

35.7 (14.3)

0.892 (113.5)

Band D

78.3

0.361

1.8 (0.7)

5.7 (2.3)

13.00

(44 356)

14.43

(49 230)

10.80

(36 850)

0.373 (47.4)

0.151

35.7 (14.3)

1.010 (128.4)

11.7 (4.7)

35.20

(120 102)

39.07

(133 306)

32.00

(109 184)

0.400

1.010 (128.4)

Mini C32

1.8 (0.7)

6.7 (2.7)

15.50

(52 886)

17.20

(58 686)

12.70

(43 332)

0.444 (56.5)

0.176

Band D

78.3

11.7 (4.7)

35.7 (14.3)

0.400

Key to Symbols:

IE = Ireland, GB = United Kingdom (Countries of destination) PMS = Maximum operating pressure of water C

12C32C52

connection via concentric ducts to a horizontal or vertical

= a room sealed appliance designed for

terminal or twin flue system.

= appliance designed for use on 2nd family gas group

2H3P

H or 3rd family gas group 3P

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 --- Installation & Servicing

GENERAL

Mini

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

(Benchmark No.)

Mini C24 47---348 --- 18 0694BM3420 Mini C28 47---348 --- 19 0694BM3420 Mini C32 47---348 --- 25A 0694BM3420 Mini S24 41 ---392 --- 98 0694BM3420 Mini S28 41 ---392 --- 99 0694BM3420

Destination countries: GB, IE

CONTENTS

Air supply 9

Benchmark Commissioning Checklist 58

Boiler clearances 6

Boiler exploded view 13

Electrical connections 19

Electrical supply 10

Fault finding 48

Flow wiring diagram 22

Flue fitting 15

Gas conversion 29

Gas safety regulations 7

Gas supply 8

Installation 14

Mandatory requirements 7

Replacement of components 34

Servicing 30

Shortlistofparts 55

Thermostatic radiator valves 11

Water connections 18

Water treatment 9

Wiring diagrams 20

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 13

SEDBUK No. % 4

Controls

Time and temperature control to heating 24/25

Time and temperature control to hot water 24/25

Heating zone valves 24

TRV’s 11

Auto bypass 11

Boiler interlock 11

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 11 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 n/a 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 Installation & Servicing

GENERAL

1 BOILER WATER CONNECTION

Wall

mounting

plate

20 (3/4”)

255 (10”)

85 (3 5/16”)

561 (22 1/16”) 101 (4”)

Pipe size O.D. mm

CH flow 22

CH return 22

Gas inlet 22

DHW cold inlet * 15

DHW hot outlet * 15

* Pipe connections not used on system boilers

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.

254 (10”)

25 (1”) 50 (2”)

(17 3/4”) overall clearance is still required, with the cupboard door open, to allow for servicing.

Side and Rear Flue

a. Providedthattheflueholeiscutaccurately,e.g.withacore

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 ONL Y

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

spaceinwhichtheboileristobeinstalledmustbeatleast wide enough to accommodate the tool.

200 (7 7/8”) 200 (7 7/8”)

147 (5 3/4”)

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

92 (3 5/8”)

Mini --- Installation & Servicing

INTRODUCTION

GENERAL

GAS SAFETY

Mini C24, Mini C28 and Mini C32 are wall mounted, low

water content, balanced flue combination gas boilers.

Mini S24 and Mini S28 are wall mounted, low water content, balanced flue system gas boilers.

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

--- between 9.10 (31 049) and 24.30 (82 912) kW (btu/h) for

model Mini C24 and Mini S24;

--- between 10.80 (36 849) and 28.40 (96 900) kW (btu/h) for

model Mini C28 and Mini S28.

--- between 12.70 (43 435) and 32.00 (109 184) kW (btu/h) for

model Mini C32.

Theboilersaresuitableforconnectiontofullypumped, pressurised sealed water systems ONLY.

AsystembypassisnotrequiredwhenTRV’sarefittedtoall radiators (see Frame 5). The boiler incorporates an automatic bypass.

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

The CH flow temperature is controlled by a temperature probe. 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 DHW heat exchanger is 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 (Mini C24, Mini C28, Mini C32 only) fits neatly within the casing. Separate fitting instructions are included with the kit. Note. If using an alternative programmer read Frame 26 first.

Horizontal Concentric Extension Ducts

Up to 4 m (13’ 1”) for models: Mini C24, Mini S24, Mini C28, Mini S28.

Up to 2,7 m (8’ 10”) for model Mini C32

Other available kits are listed in frame 9.

DHW OPERATION (combi versions)

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 C24. 10.0 (2.2) l/min (gpm) at 35 degree rise.

Mini C28 11.6 (2.6) l/min (gpm) at 35 degree rise.

Mini C32 13.1 (2.9) 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.

Mini Installation & Servicing

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,importantthatnoexternal controldevices,e.g.fluedampers,economisersetc.,are directly connected to these appliances unless covered by these Installation and Servicing Instructions or as otherwise recommended by Ideal Stelrad Group. in writing. If in doubt please enquire.

Any direct connection of a control device not approved by Ideal Stelrad Group. 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.

GENERAL

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 adequatesize,i.e.notlessthan22mmO.D.copperor3/4” BSP iron.

FLUE INSTALLATION REQUIREMENTS

Thefluemustbeinstalledinaccordancewiththe 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 Tab l e 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 200 mm ( 8”) **

4 Below balconies or a car port roof 300 mm ( 12”) **

5 From vertical drain pipes or soil

pipes*

6 From an internal or external corner

or to a boundary along side the terminal

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.

** If a reduction down to 25mm(1”) is required in any of the indicated positions, horizontal flue kit no. 200889 MUST be used. Only 1 reduction down to 25mm is allowable per

installation.

Minimum spacing

300 mm (12”)

75 mm ( 3”) **

60 mm ( 2 1/2”) **

150 mm ( 6”) **

300 mm (12”)

600 mm (24”)

1200 mm (48”)

1500 mm (60”)

300 mm (12”)

Mini --- Installation & Servicing

GENERAL

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.,To wer house, Vale Rise, Tonbridge, Kent TN9 1TB T el. +44 (0) 1732 359 888 Fax No. +44 (0) 1732 354 455 www.tfc--- group.co.uk

IMPORTANT It is absolutely ES SENTIAL 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”) 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.

Mini Installation & Servicing

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 Ideal Stelrad Group INVALID.

Ideal Stelrad Group recommend Water Treatment in accordance with the Benchmark Guidance Notes on Water T r eatment in Central Heating Systems.

Ideal Stelrad Group 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 7593:2006 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 th oroughly flushed.

Domestic Hot Water

In hard water areas where mains water can exceed 200ppm Total Hardness (as defined by BS 7593:2006 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.

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

For further information contact:

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

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

Sentinel Performance Solutions The Heath Business & Technical Park Runcorn Cheshire WA7 4QX +44 (0) 800 389 4670

GENERAL

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.

4 SEALED SYSTEM REQUIREMENTS

Central Heating

Note. Mini 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 pressureof3bar(45lb/in 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/in

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

d1. 6 litre expansion vessel; with an initial charge pressure of

0.7 bar (10.5 lb/in Mini S28.

d2. 7 litre expansion vessel; with an initial charge pressure of

1.0 bar (15.0 lb/in

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

System filling and make---up

Proceed with the following:

Stop valve Additional stop valve

CH return

Temporary hose (disconnect after filling)

) and temperature of 110 ˚C. Extra

)forMini C24, Mini C28, Mini S24 and

)forMini C32.

Hose unions

Double check valve assembly Note direction of flow

Mains Water Supply

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.

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

1.5bar(22lb/in

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

(15 lb/in

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).

Table 5 Mini C24, Mini S24, Mini C28, Mini S28

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.

5 Size of expansion vessel

For the system water expansion to be contained by the 6 litre expansion vessel fitted to the following models:

Mini C24, Mini S24, Mini C28, Mini S28

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.

). Examine for leaks.

) is reached.

0.5 0.7 1.0

0.7

in addition to 6 litre unit

fitted to boiler

0.063 0.069 0.074

Mini --- Installation & Servicing

GENERAL

For expansion volumes see Table 5.

Ta b l e 6 M i n i C 3 2

System charge pressure (bar)

Safety valve setting 3.0

Vessel pre ---charge pressure (bar)

System volume (litres) Volume of expansion vessel

75 --- --- ---

100 --- --- 0.4

125 0.8 1.6 2.3

150 2.5 3.4 4.1

175 4.0 5.1 6.0

200 5.6 6.8 7.8

225 7.2 8.6 9.7

250 8.8 10.3 11.5

275 10.3 12.0 13.4

300 11.9 13.7 15.2

Multiply this factor by system volume and deduct 7 litres to obtain size of additional vessel for other system volumes.

For the system water expansion to be contained by the 7 litre expansion vessel fitted to the following model:

Mini C32

the cold system volume must not exceed:

0.5 0.7 1.0

0.7

in addition to 7 litre unit

fitted to boiler

0.063 0.069 0.074

111 litres when pressurised to 0.5 bar (cold)

101 litres when pressurised to 0.7 bar (cold)

95 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 6.

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

mH2O

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.

5 BOILER CONTROL INTERLOCKS

Thermostatic radiator valves.

Ideal Stelrad Group. 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 TRV 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 C24, Mini C28 and Mini C32 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.

Mini Installation & Servicing

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

Room T/stat

Balancing valve

5 When connecting to suitable showers,i.e.thosedesigned

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.

GENERAL

7BOILERWATERCIRCUITDIAGRAM

M i n i C 2 4 --- M i n i C 2 8 --- M i n i C 3 2

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 B y --- p a s s v a l v e

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

Mini S24 --- Mini S28

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

28 29

27 Overheat thermostat

28 Pump

29 Pump vent plug

30 CH temperature probe

31 CH flow switch

32 DHW temperature probe

33 CH circuit temperature/pressure gauge

Mini --- Installation & Servicing

8 B O I L E R A S S E M B LY ---

Exploded View

INSTALLATION

29*

27*

18*

11*

INSTALLATION

1Venturi 2Fan 3 Flue hood 4 Flame detection electrode 5 Overheat thermostat 6 Primary heat exchanger 7 Inner case cover 8 Ignition electrodes 9 Heat exchanger return pipe 10 CH temperature probe 11 DHW temperature probe 12 Main circuit drainage cock

* Mini C24, Mini C28 and Mini C32 only

Mini Installation & Servicing

25 23

2124

13 Auto air vent 14 Pump 15 Electronic control pcb 16 3 bar pressure relief valve 17 Return manifold 18 DHW flow switch* 19 Right hand panel 20 Boiler front panel 21 Appliance data badge (inside) 22 Left hand panel 23 CH circuit pressure gauge 24 Model identification & instructions

25 Control panel door 26 CH flow switch 27 3 way diverter valve* 28 Heat exchanger flow pipe 29 DHW heat exchanger* 30 Bypass pipe 31 Gas valve 32 Gas valve outlet pipe 33 Injector manifold 34 Burner 35 Air pressure switch 36 Expansion vessel

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

ATheboiler.

B Hardware pack

C Wall mounting plate

D Wall mounting template

E Installation & Servicing instructions.

F The User’s Instructions.

INSTALLATION

G Filling loop assembly

H Restrictor pack

Pack B contents

I Air intake pipe ø 100 mm (4”)

J Flue pipe ø 60 mm (2” 3/8) with terminal grille assembly

KBand

L Turret- --air pipe gasket

M Fluepipegaskets ---2off

N Boiler --- turret gasket

O Flue turret

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

Q Self tapping screw 4,2x13 --- 2 off

R Wall finishing gaskets - -- 2 off

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. *

* Mini C24, Mini C28 and Mini C32 only

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

F Electronic programmer kit * F Extension duct kit pack D (ø 60/100) F Flue support kit 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 Pitched roof tile (for roof flue kit) F Flat roof tile (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 (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) female ---female F 90˚ Elbow kit (ø 80) male --- female F 45˚ Elbow kit (ø 80) male --- female F Condense drain (ø 80) F Condense trap F Stand ---off bracket F Pre --- piping frame F Natural gas to LPG conversion kit F LPG to natural gas conversion kit

10 PACKAGING

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

Mini --- Installation & Servicing

INSTALLATION

11 FITTING THE FLUE SYSTEM

The maximum total equivalent lengths are given in Table 7 and Table 8 for co--- axial pipes ø 60---100 mm, Ta b l e 9 f o r c o --- a x i a l p i p e s ø 8 0 --- 1 2 5 m m a n d i n t h e diagrams for the ø 80 mm twin pipes air ---flue systems.

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

Condensate Collection

When a length of vertical pipe is used in the system and the length of flue exceeds the following, a condensate drain and trap must be fitted to the lowest point of the system. The trap must be connected to a suitable waste pipe.

ø80---125mm co ---axial pipes --- 1 metres ø80twinfluepipes ---7metres

Flue Restrictors

Two different sized restrictors are supplied with the boilers Mini C24, Mini S24, Mini C28, Mini S28. A 44 mm size is fitted to the boiler and a 47 mm size is supplied in a separate bag.

Two different sized restrictors are supplied with the boiler Mini C32 A 47 mm size is fitted to the boiler and a 50 mm size is supplied in a separate bag.

The appropriate restrictor, when necessary, must be fitted in the flue outlet elbow as indicated in following picture.

Table 9--- Models Mini C24, Mini S24, Mini C28, Mini S28

Pipe length (ø 80/125) Restrictor

Between 0,5 (19.5“) and 1,5 m (59“) ø44mm

More than 1,5 m (59“) up to 6,5 m (21’ 4“) ø47mm

More than 6,5 m (21’ 4“) up to 8,5 m

no restrictor

(27’ 10“)

Ta b l e 1 0 --- M o d e l M i n i C 3 2

Pipe length (ø 80/125) Restrictor

Between 0,5 (19.5“) and 4 m (13’ 1“) ø47mm

More than 4 m (13’ 1“) up to 6 m (19’ 8“) no restrictor

For the correct use of the restrictors with twin pipes refer to the following diagram for the models Mini C24, Mini S24, Mini C28 and Mini S28.

Flue exhaust (m)

32 30 28 26 24 22 20 18 16 14 12 10

8 6 4 2 0

0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32

Restrictor

47 mm

Allowed values

Restrictor

Mini C24 Mini S24 Mini C28 Mini S28

Air intake (m)

INSTALLATION

For the correct use of the restrictors with co ---axial pipes ø 60/100 mm refer to: Tab l e 7 f or m o de l s Mini C24, Mini S24, Mini C28, Mini S28. Tab l e 8 f or m o de l Mini C32

For the correct use of the restrictors with vertical roof kit ø 80/125 mm refer to: Tab l e 9 f or m o de l s Mini C24, Mini S24, Mini C28, Mini S28 Table 10 for model Mini C32.

Table 7 --- Models Mini C24, Mini S24, Mini C28, Mini S28

Pipe length (ø 60/100) Restrictor

Between 0,5 (19.5“) and 1 m (39“) ø44mm

More than 1 m (39“) up to 2 m (78.5“) ø47mm

More than 2 m (78.5“) up to 4 m (157“) no restrictor

Ta b l e 8 --- M o d e l M i n i C 3 2

Pipe length (ø 60/100) Restrictor

Between 0,5 (19.5“) and 1 m (39“) ø47mm

More than 1 m (39“) up to 2,7 m (8’ 10“) no restrictor

Refer to the following diagram for the model Mini C32.

Flue exhaust (m)

0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16

Restrictor

50 mm

Allowed values

Restrictor

Mini C32

Air intake (m)

Mini Installation & Servicing

11 FITTING THE FLUE SYSTEM (cont.)

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 grille.

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 1m or 1,5m respectively.

Horizontal and Vertical Outlet kits (60 - --100) have a minimum 300mm length, up to a maximum shown in tables 7 & 8.

INSTALLATION

Cutting lengths of flue and air ducts

Measure the wall thickness and, when using a side outlet, the gapbetweentheinnerwallandtheboilersidecasing. Use the following chart to calculate the cutting length of air duct.

Completely insert the flue duct in the air duct. Mark and cut the flue duct so it protrudes 27 mm from the air duct edge.

Cut this end

Air duct

Rear Outlet Wall thickness + 67 mm

Rear outlet + Stand - --off Wall thickness + 102 mm

S id e O u t l e t --- L H & R H Wall thickness + Gap + 120mm

Groove

Flue duct

Horizontal Concentric

INSTALLATION

For each additional 45˚ M&F and 90˚ M&F flue bend used, themaximumpermissiblelengthoffluesystemmustbe reduced by 0,9m or 1,65m respectively.

For each additional 90˚ F&FFluebendused,themaximum permissiblelengthoffluesystemmustbereducedby2,75m.

Lengths of allowable equivalent flue outlet and air inlet ducts are indicated in the graphs within this frame.

N.B.: The air intake and flue outlet must not terminate on opposite sides of the building.

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.

Twi n Pi p e

Air duct

Rear Outlet Wall thickness + 215 mm

Rear outlet + Stand --- off W all thickness + 250 mm

Side Outlet --- LH Wall thickness + Gap + 83 mm

Side Outlet --- RH Wall thickness + Gap + 273mm

Flue Duct + Grille

Rear Outlet Wall thickness + 225 mm

Rear outlet + Stand --- off W all thickness + 260 mm

Side Outlet --- LH & RH Wall thickness + Gap + 278mm

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.

12 REAR FLUE ASSEMBLY

Legend

1 Wall finishing gaskets 2 Self tapping screw 4,2x13 3 Self tapping screws 4,8x13 4 Flue turret 5 Boiler --- turret gasket 6 Fluepipegaskets 7 Turret--- air pipe gasket 8Band 9 Flue pipe ø 60 mm with terminal grille assembly 10 Air intake pipe ø 100 mm

When installing a horizontal flue system, Co---axial or Twin Pipe, all ducts MUST have a fall of 3% AWAY from the boiler.

Mini --- Installation & Servicing

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 plumbline. 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

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 plumbline.

3 Mark onto the wall the following:

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

Mark the flue duct centre from the corner (see diagram and template)

INSTALLATION

Extended centre

Spirit level

Note. mark th e centre of the hole as well as the circumference.

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),

ensuringthattheholeissquaretothewall.

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 a c c urately cut and the rubber weather seal trimmed around the groove provided.

5” diameter flue hole

Section through wall

Note: Check all of the hole positions before drilling.

Mini Installation & Servicing

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.

17 MOUNTING THE BOILER

INSTALLATION

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 21) and strip off the protective coating. The panels may be placed to one side and re --- fitted when the installation is complete.

INSTALLATION

Fit the horizontal 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.

Central Heating flow

Domestic hot water outlet *

* Mini C24, Mini C28 and Mini C32 only

Gas inlet

Domestic cold water inlet *

Central Heating return

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 an optional additional frame available in separate box. See illustration for upward pipework routing

Mini C shown

Mini --- Installation & Servicing

INSTALLATION

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.

20 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 mm Table 16. (0.5mm 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.

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

(24 x 0.2mm) and to BS. 6500,

flex is not acceptable --- for mechanical,

Pressure relief valve

Discharge pipe

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 3.15 AF.

Mini C24, Mini C28 Mini C32 only

For external controls wiring see frame 26. 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.

For Mini S24, Mini S28 refer to frame 27.

INSTALLATION

21 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.

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.

Mini C24, Mini C28 , Mini C32 only

Thermostat link. Remove when wiring external thermostats. Refer to frames 26 and 27

Mains

Power supply terminal block

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

panels and pull the control panel.

Mini Installation & Servicing

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.

INSTALLATION

22 PICTORIAL WIRING

Mini C24, Mini C28, Mini C32

Wiring diagram for boiler equiped with electronic control p.c.b. t ype: Bertelli & Partners DIMS11 --- SA03/16740

Electric supply

terminal block

INSTALLATION

gnye

External controls

terminal block

123

bubnbk

bubu

Three way

diverter valve

bnbubk

K3 K4

Pump Fan

gnye

Primary circuit

flow switch

Air pressure

switch

Ignition

electrodes

Flame detection

electrode

gnyebu

gy bk bk

gnye

COM

gywhburdbububk

X11

LD1LD2LD3

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

D.h.w. flow

switch

C.h. temperature

probe NTC

1 2 3 4 7 8 95 10 11 12 13 14

17 18

LD1LD2LD3

bn bu

Modulating

gas valve

SB1

Safety

thermostat

19 20 21 22 23

LD4

Electronic control P.C.B.

D.h.w. temperature

probe NTC

24 25 26 27

SB1

15 16

2829303132333435363738

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

LD4

rd bk

Time switch

Mini --- Installation & Servicing

INSTALLATION

23 PICTORIAL WIRING

Mini S24, Mini S28

Wiring diagram for boiler equiped with electronic control p.c.b. t ype: Bertelli & Partners DIMS11 --- SA03/16740

Electric supply

terminal block

gnye

External controls

terminal block

bubnbk

bubu

COM

Ignition

electrodes

Flame detection

electrode

X11

INSTALLATION

Pump Fan

123

K3 K4

gnye

bk bk

gnyebu

gnye

Primary circuit

flow switch

Air pressure

switch

bububk

LD1LD2LD3

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

C.h. temperature

probe NTC

1 2 3 4 7 8 95 10 11 12 13 14

17 18

LD4

SB1

Electronic control P.C.B.

bn bu

Modulating

gas valve

LD1LD2LD3

Safety

thermostat

19 20 21 22 23

24 25 26 27

SB1

15 16

2829303132333435363738

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

LD4

Mini Installation & Servicing

24 FUNCTIONAL FLOW DIAGRAM

Mini C24, Mini C28, Mini C32

INSTALLATION

Gas Valve (on---o ff o perato rs)

Air pressure switch

Fan

CH flow switch

Electronic

control pcb

DHW flow switch

bkbk bu

33342829

Gas Valve (modulation coil)

Three way div. valvebn

DHW temp.rd probe NTC

Safety thermostat

151639

Ignition electrodes

Detection electrode

Pump

CH temp. probe NTC

Mini --- Installation & Servicing

25 FUNCTIONAL FLOW DIAGRAM

Mini S24, Mini S28

Gas Valve (on---o ff o perato rs)

INSTALLATION

CH flow switch

bkbk

2829

INSTALLATION

Gas Valve (modulation coil)

Fan

Air pressure switch

Safety thermostat

Electronic

control pcb

151639

Ignition electrodes

Pump

CH temp. probe NTC

Mini Installation & Servicing

Detection electrode

INSTALLATION

26 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 3.15 AF.

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

INSTALLATION

230V supply

ELECTRICAL CONNECTIONS FOR A COMBI BOILER

Optional Programmer Kit

For the models Mini C24, Mini C28 and Mini C32 (combi) an optional digital programmer kit is available with its relevant instructions.

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).

For system boliers refer to frame 27.

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 pi pework.

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

Optional frost’stat

Room thermostat

Power supply terminal block

External controls

terminal block

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 theboilerwillbeleftoffformorethanadayorsothenafrost thermostat should be wired into the system. To maintain frost

27 ELECTRICAL CONNECTIONS FOR A

SYSTEM BOILER

The following diagram shows a possible way to connect an external programmer to a mid--- position diverter valve to

Optional frost’stat

Valve colour key BR --- Brown

BL --- Blue GR --- Grey OR --- Ora nge

MAINS 230V a.c. Switched 3 Amp fused, spur

Progra mmer

M i d --- p o s i t i o n diverter valve

External programmer

Optional frost’stat

Room thermostat

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

provide independent timed and thermostatic control of heating and water.

The earth wires are not shown for clarity. Earth wiring must be fitted as necessary

Room thermostat

Cylinder thermostat

Do not

remove

LN Power supply terminal block

321

Power supply terminal block

External controls

terminal block

Mini --- Installation & Servicing

28 INITIAL LIGHTING

INSTALLATION

Mini C24 Mini C28 Mini C32

Legend

A Appiance operation lamps

B Domestic hot water temperature control Mini C24,

Mini C28, Mini C32

BServiceknobMini S24, Mini S28

C Main switch and radiator temperature control

D Boiler reset button

E Lock - --out signal lamp

F Programmer (optional) for Mini C24, Mini C28,

Mini C32 boilers only.

G System pressure and temperature gauge

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 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

5 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.

EBCD FG

Mini S24 Mini S28

Central Heating flow

Domestic hot water outlet

6 Check that the gas service cock is ON.

7 Switch the electricity supply ON and check that all

external controls are calling for heat.

8 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.

9 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.

10 Test for gas soundness around ALL boiler gas

components, using leak detection fluid.

11 Operate the boiler for 10 minutes to stabilise the burner

temperature.

12 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 29.

13 Set the boiler main switch to ’O’.

14 Remove the pressure gauge and tube. Replace the

sealing screw in the pressure test point. Ensure a gas tight seal is made.

15 Refit the boiler front panel using the screws previously

removed.

16 Switch the boiler on again.

Gas inlet

Domestic cold water inlet

INSTALLATION

Central Heating return

Mini C shown

Mini Installation & Servicing

INSTALLATION

29 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

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

Ignition rate adjustment

1 Turnontheboiler.

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 Rotate the radiator temperature control C as indicated in

the next figure and ensure that the room thermostat, if fitted, is set to “heat demand”.

5 Run the boiler in c.h. mode (for combi boilers: do not

open any d.h.w. tap)

Mini C24 Mini C28 Mini C32

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 2 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 2 at page 4 (burner pressure). By rotating clockwise the pressure increases.

10 Turntheboileroffandre---connectthewiretothe

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

CA DEB

Mini S24 Mini S28

6 Press and hold the reset button D for about 10 seconds

until the lock --- out signal light E blinks.

7 The lamps A should give the indication of the next figure;

ifnotthenpresstheresetbuttonDuntilyouobtainit.

Where:

8 Press and hold the reset button D for about 5 seconds

until the lock - --out signal light E is switched off.

The boiler runs in c.h. mode and the lights A give the follow indication:

Where: Flashing lamp, alone

9 Rotate the knob B on a position corresponding to an

adequate ignition pressure. By rotating clockwise the pressure increases.

Suggested ignition pressures:

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

10 Make a note of the position of the knob B.

Lamp ON

Lamp OFF

or simultaneously with an other lamp.

Lamp OFF

Mini --- Installation & Servicing

INSTALLATION

11 Turn the boiler off and on positioning the main switch C as

indicated in the next figure.

13 Press the reset button D repeatedly (4 times) until the

lamps A give the follow indication:

Mini C24 Mini C28 Mini C32

CA DEB

Mini S24 Mini S28

12 Press and hold the reset button D for about 10 seconds

until the lock-- -out signal lamp E blinks.

30 ANTI CYCLING SETTING

It is possible to set the minimum delay time that must pass between two ignitions of the burner in c.h. function mode.

1 Turn the boiler on positioning the main switch C as follow:

Mini C24 Mini C28 Mini C32

Where:

14 Turn the knob B to the minimum (fully counterclockwise)

and then on the position noted on step 10. By turning the control B the lock - --out signal lamp E blinks quickly (2 per second) indicating that the setting has changed and must be memorized.

15 To memorize the setting press and hold the reset button D

for about 5 seconds until the lamps A briefly blink simultaneously.

16 To reset the boiler to the normal operation turn it off and

on by the main switch C checking the ignition pressure and that the burner lights up uniformly. The boiler automatically resets to its normal operation after 10 minutes if the above reset operation is not performed.

At this time it is possible to determine the current setting by keeping the reset button D pressed for more than 5 seconds. The lamps A will flash a number of times corresponding to the setting.

4 To change the setting turn the knob B to a position

corresponding to the desired delay. By turning the control B, the lock ---out signal lamp E blinks quickly (2 per second) indicating that the setting has changed and must be memorized.

Lamp ON

Lamp OFF

INSTALLATION

CA DEB

Mini S24 Mini S28

2 Press and hold the boiler reset button D for about 10

seconds until the lock---out signal lamp E blinks

3 The lamps A should give the indication as in next figure

(reignition frequency). If not, press the reset button D repeatedly to obtain it.

Where:

Lamp ON

Lamp OFF

31 COMMISSIONING AND TESTING

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.

Mini Installation & Servicing

11/2

5 To memorize the setting press and hold the reset button D

for about 5 seconds until the lamps A briefly blink simultaneously.

6 To reset the boiler to the normal operation turn it off and

on by the main switch C. The boiler automatically resets to its normal operation after 10 minutes if the above reset operation is not performed.

The factory setting anti cycling time is 3 minutes.

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.

51/2

81/2

Delay (minutes) Setting No.

INSTALLATION

32 GENERAL CHECKS

Make the following checks for correct operation:

1Hotwater(Mini C24, Mini C28 and Mini C32 models).

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 ˚Crise is obtained at the tap. This corresponds to a flow rate of about

10.0 (2.2) l/min (gpm) Mini C24

11.6 (2.6) l/min (gpm) Mini C28

13.1 (2.9) l/min (gpm) Mini C32

INSTALLATION

d. Tur n of f th e D H W ta p .

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 G a s r a t e --- G2 0

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

The gas rate will normally be

47.0 (1.66) litres/min (ft

Mini S24

54.8 (1.94) litres/min (ft

Mini S28

62.2 (2.20) litres/min (ft

checked at the gas meter , with no other appliance in use.

/min) for the models Mini C24 and

/min) for the models Mini C28 and

/min) for the model Mini C32

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

11.7 (4.7) mbar (in. w.g.) for all models.

4 Water circulation system

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

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.

5Fluesystem

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 --- Installation & Servicing

INSTALLATION

33 GAS CONVERSION

1 Check that the gas cock fitted under the boiler is turned

off and the appliance is switched off at the mains isolating spur.

2 Remove the front panel of the case.

3 Takeoffthelidofthesealedchamber.

4 Take the front panel of the combustion chamber off and

remove the burner as explained in frame 37.

5 Carry out the conversion for the type of gas, replacing the

burner injectors correctly as explained in frame 45.

6 Re--- assemble the burner, the front panel of the

combustion chamber and the lid of the sealed chamber.

7 Switch on the appliance at the mains isolating spur.

8 Turn the boiler OFF positioning the main switch C as in

figure below.

Mini C24 Mini C28 Mini C32

CA DEB

Mini S24 Mini S28

9 Disconnect the CH temperature probe (30 on page 12).

10 Press and hold the reset button D for about 10 seconds

until the lock-- -out signal lamp E blinks.

11 Connect the CH temperature probe (30 on page 12).

12 Press the reset button D repeatedly (4 times) until the

lamps A give the follow indication:

Where:

Lamp ON

Lamp OFF

At this time it is possible to determine the current setting by keeping the reset button D pressed for more than 5 seconds. The lamps A will flash a number of times corresponding to the setting of the knob B (see next figure).

Gas type

Setting No.

NATURAL

GAS

Gas supply

Natural gas 1 125 mA

L.P.G. 4 165 mA

13 To change the setting turn the knob B to a position

corresponding to the gas used as shown in the figure above. By turning the control B, the lock--- out signal lamp E blinks quickly (2 per second) indicating that the setting has changed and must be memorized.

14 To memorize the setting press and hold the reset button

D for about 5 seconds until the lamps A briefly blink

simultaneously. 15 Open the gas cock. 16 To reset the boiler to the normal operation turn it ON by

the main switch C on the desired operation and checking

the ignition pressure and that the burner lights up

uniformly.The boiler automatically resets to its normal

operation after 10 minutes if the above reset operation is

not performed.

The factory setting is Natural gas.

17 Calibrate the gas valve according to the instructions given

in this manual. 18 Set the correct gas pressure for central heating output

required. 19 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 and

replace the adjustment protection cap. 20 Replace the front panels of the case. 21 Check the correct operation of the boiler.

Position of knob B

Approx. Max current through the modulator device

L.P.G.

INSTALLATION

34 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.

Mini Installation & Servicing

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.

SERVICING

35 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,checkingthemeasuredrateagainstthefiguresgivenin 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.

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 IftheratioofCO/CO

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 36 to 41 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 appliancebeforeservicing.

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.

is less than ,004 and the gas rates

Air intake sampli ng point

Exhaust gas sampli ng point

Mini --- Installation & Servicing

SERVICING

36 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

Mini C shown

Mini Installation & Servicing

SERVICING

37 BURNER REMOVAL AND CLEANING

1 Disconnect the electrical supply. 2 Remove outer and inner casing (refer to frame 36). 3 Undo the screws A and remove the combustion chamber

panel B.

SERVICING

6 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.

7 Inspect the spark and detection electrodes. Ensure they

are clean and in good condition; replace if necessary.

8 Check the spark electrodes gap is correct.

4 mm (5/32”)

10 mm (3/8”)

Ignition

Female

Mini C24, Mini C28, Mini S24, Mini S28

Detection

Burner blade

Male

4 Disconnect the electrodes leads. 5 Undo the four screws C placed at the right and left sides

of the burner and extract it.

38 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.

Burner blades

4 mm (5/32”)

10 mm (3/8”)

Detection

10 mm

Male

Female

Mini C32

9 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 29 “To adjust pressures”.

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

Ignition

(3/8”)

39 CLEANING THE HEAT EXCHANGER

1 Open the combustion chamber as explained in steps 1 to

3 of frame 37.

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.

Mini --- Installation & Servicing

SERVICING

4 0 R E --- A S S E M B LY

Re --- assemble the boiler in the following order:

3 Refit the burner.

4 Reconnect the electrodes to the electronic pcb. See frame

37 for correct connectors.

5 Refit the combustion chamber panel.

41 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.

6 Refittheinnercasecover.

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

7 Refittheboilersideandfrontpanels.

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

9 Reconnect the electrical supply.

SERVICING

E E

If the right clearance is less than 50 cm (20”)....

6 Remove the combustion chamber panel (see frame 36) 7 Remove the 3 screws F and remove the flue hood with the

fan.

8 Unscrew the 3 screws E and remove the fan.

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

or renew as necessary. Refer to frame 52 for replacement.

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

10 Check the venturi G for cleaness.

4 Disconnect the pipe which connects the venturi device to

the air pressure switch.

5 Unscrew the screws C and remove the clamp D.

If the right clearance is at least 50 cm (20”)....

11 Re--- assemble in reverse order.

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

--- +

6 Unscrew the 3 screws E and remove the fan and skip to

step 9

Mini Installation & Servicing

SERVICING

REPLACEMENT OF COMPONENTS

42 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.

43 SPARK AND DETECTION

ELECTRODE REPLACEMENT

1 Disconnect the electrical supply. 2 Remove outer and inner casing (refer to frame 36). 3 Open the combustion chamber and disconnect the

electrodes leads. 4 Remove the burner. Refer to frame 37. 5 Undo the screws that hold the electrodes and remove. 6FormodelsMini C24, Mini C28, Mini S24, Mini S28,fit

new electrodes as necessary following the sequence

illustrated.

Ignition 1

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.

Burner blades

4 mm (5/32”)

10 mm (3/8”)

Detection

10 mm

Male

Female

Mini C32

Ignition

(3/8”)

Ignition 2

7 Check the spark gap.

Detection 3

4 mm (5/32”)

10 mm (3/8”)

Ignition

Female

Mini C24, Mini C28, Mini S24, Mini S28

Detection

Male

44 BURNER REPLACEMENT

1 Remove the burner as explained in frame 37 2 Remove the spark and detection electrodes.

Refer to frame 43.

Burner blad

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

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.

Mini --- Installation & Servicing34

SERVICING

45 BURNER INJECTORS

REPLACEMENT

1 Remove the burner. Refer to frame 37.

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.

46 OVERHEAT THERMOSTAT

REPLACEMENT

1 Remove outer and inner casing (refer to frame 36).

For models Mini C28, Mini S28 and Mini C32 remove the

screw A and the plate B.

Injectors

Burner

Gas manifold

SERVICING

2 Disconnect the wiring C . 3 Remove the spring D which holds the overheat thermostat

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

4 Re --- assemble in reverse order. 5 Apply an adequate quantity of heat conducting

compound between the pipe and the thermostat.

Mini Installation & Servicing 35

SERVICING

47 TEMPERATURE PROBE

REPLACEMENT

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

to frame 36).

Removal of CH temperature probe

3 ToremovetheCHtemperatureprobecloseoffthe

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

drainage cock.

SERVICING

Do not release CH pressure using the pressure relief

valve. It may cause debris within the system to foul

the valve.

Removal of DHW temperature probe (Combi boilers)

3 To remove the DHW temperature probe close off the

isolating cock of the DHW circuit at the bottom of the boiler.

4 Empty the DHW circuit.

Replacement

5 Disconnect the leads from the probe to be replaced and

unscrew it .

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

and re --- assemble in reverse order.

DHW temperature

probe

CH tempera-

ture probe

48 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 approx. 6 400 Ω*

L o w e r o n --- o f f o p e r a t o r approx. 920 Ω*

* 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.

Drainage cock

Replacement

5 Remove the screw B, withdraw the coils unit C. 6 Replace it and re ---assemble in reverse order.

Mini --- Installation & Servicing36

49 GAS VALVE REPLACEMENT

SERVICING

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 36).

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.

50 WATER TEMPERATURE--- PRESSURE

GAUGE R EPLACEMENT

1 Disconnect the electrical supply.

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

to frame 36).

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 21).

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

gaugeEandremoveit.

7 Re --- assemble in reverse order.

SERVICING

51 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,

thanitcanbeleftinplaceandanewvesseladdedtothe

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 36).

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 Completely unscrew the connection A, the locknut B and

remove the expansion vessel from the top of the boiler.

6 Re --- assemble in reverse order.

Mini Installation & Servicing 37

SERVICING

52 FAN REPLACEMENT

1 Disconnect the electrical supply. 2 Remove outer and inner casing. 3 Disconnect the connectors A and the earth connection B.

SERVICING

4 Disconnect the pipe which connects the venturi device to

the air pressure switch. 5 Unscrew the screws C and remove the clamp D.

If the right clearance is at least 50 cm (20”)....

6 Unscrew the 3 screws E and remove the fan.

E E

7 Re --- assemble in reverse order.

If the right clearance is less than 50 cm (20”)....

6 Remove the combustion chamber lid (see frame 37)

7 Remove the 3 screws F and remove the flue hood with the

fan.

8 Unscrew the 3 screws E and remove the fan.

9 Re --- assemble in reverse order.

53 VENTURI REPLACEMENT

1 Removethefan(seeframe52). 2 Remove and replace the venturi device A by unscrewing

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

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

--- +

Mini --- Installation & Servicing38

SERVICING

54 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 36. 3 Disconnect the pressure sensing pipe from the air

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

switch. 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 52 and to the following illustrations in accordance with the type of pressure switch used.

”H” connection

(not used)

”L” connection

SERVICING

COM

N.O.

”L” connection

N.C.

”H” connection

(not used)

55 PUMP REPLACEMENT COMPLETE

1 Disconnect the electrical supply.

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

to frame 36).

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 Unscrew the locknut B and move the pipe upwards

freeing it from the outlet port of the pump.

6 Remove the fork C and the capillary pipe.

7 Remove the locking plate D right.

8 Loosen the connection E, remove the fork F and remove

thepipeG

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

frame

10 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.

Mini Installation & Servicing 39

56 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

21).

3 Remove the screws A and remove the service panel

4 To gain access to the electronic control/ignition p.c.b.

remove the screws B and remove the control panel lid.

SERVICING

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.

SERVICING

8 Unscrew the four screws that hold the electronic

control/ignition p.c.b. on to the control panel.

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

the wiring.

10 Re--- assemble in reverse order.

Important

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

11 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.

12 Insert the spindles in the control panel knobs until the

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

13 While tightening the screws that fix the electronic

control/ignition 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 D and the tab E. Replace the wiring connections ensuring correct engagement in the sockets.

6 To disconnect the connectors indicated in the next figure,

delicately press the hook present on one side of each

socket.

7 Remove the spindles of the two control knobs by

delicately pulling them with pliers in the direction shown

by the arrows.

Attention

After installing the electronic control/ignition p.c.b.:

Combi boilers (Mini C24, Mini C28, Mini C32)

14 Make sure the CH (

adjustment knobs can move freely for the complete range. If not, remove the spindle again as described at step 7, turn the knob half a turn and re ---insert the spindle.

System boilers (Mini S24, Mini S28)

14 Make sure the CH (

adjustment knobs can move freely for the complete range. If not, remove the spindle again as described at step 7, turn the knob half a turn and re ---insert the spindle.

)andDHW( ) temperature

) temperature and Service ( )

Mini --- Installation & Servicing40

SERVICING

15 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. 16 Open the gas inlet cock and check the boiler operates

correctly. The replacement PCB is supplied pre--- set for Natural Gas

and an anti cycling time of 3 minutes. If the installation requires adjustment of these settings refer to frames 29 and 30 for the procedures

If required, to check the PCB is set correctly for this boiler type the following procedure should be followed.

Boiler mode setting

17 Remove the front panel of the case. 18 Position the control knob C as in the figure below and

disconnect the C.h. temperature probe.

Mini C24 Mini C28 Mini C32

CA DEB

22 To change the setting turn the knob B to the position

shown on the previous figure. By turning the knob B the lock---out signal lamp E blinks quickly (twice per second) indicating that the setting as changed and must be memorised.

23 To memorize the setting keep pressed the reset button D

for about 5 seconds until the lights A briefly blink simultaneously.

24 Press the reset button D (once) until the lamps A give the

indication as follow:

Where:

It is now possible to check the current setting by pressing reset button D for more than 5 seconds. The three lamps A will flash a number of times corresponding to the setting of point22.Atthispointonlytherightgreenlightflashes.

Lamp ON

Lamp OFF

SERVICING

Mini S24 Mini S28

19 Press and hold the reset button D for about 10 seconds

until the lock-- -out signal lamp E blinks. 20 Connect the c.h.temperature probe. 21 Press the reset button D repeatedly (twice) until the lamps

A give the indication as follows (boiler mode).

Where:

Lamp ON

Lamp OFF

1flashfor combi models

25 Turn the knob B clockwise and then to minimum position.

By turning the knob B, the lock --- out signal lamp E blinks quickly (2 per second) indicating that the setting has changed and must be memorized.

26 To memorize the setting press and hold the reset button D

for about 5 seconds until all the three lamps A briefly blink simultaneously.

27 To reset the boiler to the normal operation turn it off and

on by the main switch and radiator temperature control C. The boiler automatically resets to its normal operation after 10 minutes if the above reset operation is not performed.

4flashesfor system boilers

Mini Installation & Servicing 41

SERVICING

57 CH FLOW SWITCH REPLACEMENT

1 Disconnect the electrical supply.

2 Remove the front casing panel.

3RemovetheforkA.

4 Open the box B and disconnect the switch.

SERVICING

58 CH FLOW SWITCH MEMBRANE

REPLACEMENT

1 Disconnect the electrical supply. 2 Remove front casing panel (refer to frame 36). 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

5 Re --- assemble in reverse order.

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

N.O.

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.

59 DHWFLOWSWITCHREPLACEMENT

Mini C only

1 Disconnect the electrical supply. 2 Remove the front panel of the case (refer to frame 36). 3 Disconnect the connector A and remove the sensor B 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

A B

Mini --- Installation & Servicing42

SERVICING

60 DHW FILTER AND FLOW LIMITER

REPLACEMENT Mini C only

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 Unscrew the body C and extract the flow switch group. 5 To remove the filter B from the flow switch group separate

it from the threaded ring by levering it. 6 Re --- assemble in reverse order.

A --- f l o w s w i t c h

C --- body

O --- r i n g

Spring

Magnetic ring

Float

Flow limiter

Threaded ring

B --- f i l t e r

Flow limiter

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

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

The Mini C32 model is factory fitted with a 14 litre/min. flow limiter.

Ta b l e 1 1

Nominal flow rate (litres/min)

10 Yellow

12 Brown

14 Pink

To install the threaded ring with the flow limiter:

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 flow switch group (see frame 59 above)

5 Unscrew the threaded ring and remove it from the body C.

6 Extract the flow limiter.

7 Fit the correct colour coded limiter (see Table 11 above)

and screw the threaded ring tight into the body C.

8 Re --- assemble in reverse order.

Colour

SERVICING

Mini Installation & Servicing 43

SERVICING

61 PRIMARY HEAT EXCHANGER

REPLACEMENT

1 Disconnect the electrical supply. 2 Remove outer and inner casing as explained in frame 36. 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.

SERVICING

5 Remove the combustion chamber panel A by unscrewing

the screws B. For models Mini C28, Mini S28 and Mini

C32 only, remove the screw C and the plate D. 6 Remove the clips E and the safety thermostat F. It is not

necessary to disconnect it from the wiring.

7 UnscrewthelocknutG,liftthepipeHandrotateitright

then move it downwards freeing it from the heat

exchanger connection. 8 Completely unscrew the connection I 9 Move the pipe J downwards freeing it from the heat

exchanger connection.

10 Remove the heat exchanger by sliding it forwards. 11 Re--- assemble in reverse order.

Mini --- Installation & Servicing44

SERVICING

62 DHW HEAT EXCHANGER

REPLACEMENT Mini C only

1 Disconnect the electrical supply. 2 Remove outer casing (refer to frame 36). 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 Removethedivertervalveactuator(seeframe63). 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 theleftsideoftheboiler.

SERVICING

63 DIVERTER VALVE ACTUATOR

REPLACEMENT Mini C only

1 Disconnect the electrical supply.

2 Remove front casing panel (refer to frame 36).

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 22 for the correct wiring connection.

Mini Installation & Servicing 45

64 DIVERTER VALVE INTERNAL PARTS

REPLACEMENT Mini C only

1 Disconnect the electrical supply.

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

36).

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.

SERVICING

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 Removethedivertervalveactuator(seeframe63).

7 Remove the fork D and remove the primary circuit flow

switch E.

8 Disconnect the temperature probe F.

9 Unscrew the connector G, disconnect the CH flow and

DHW outlet isolator valves.

SERVICING

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

internal parts of the three way diverter valve.

10 Remove the DHW heat exchanger (see frame 62).

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

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

group.

65 PROGRAMMER REPLACEMENT

Mini C only (if fitted)

1 Disconnect the electrical supply.

2 Gain access to the main control p.c.b. (steps 1 to NO TAG

of frame 56).

3 Disconnect the wiring at the programmer.

66 CH DRAIN COCK REPLACEMENT

1 Disconnect the electrical supply

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

36).

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 drain cock A from the return body. 6 Re --- assemble in reverse order.

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 22 for the correct wiring connection.

6 Replace the panels and check the operation of the new

programmer.

Mini --- Installation & Servicing46

FAULT FINDING

67 ELECTRONIC CONTROL/IGNITION

P.C.B. OPTICAL INFORMATION

The electronic control/ignition 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 position)

1secondON1secondOFF

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

Normally operating boiler

C.h. operation

D.h.w. operation (Mini C only)

Frost protect operation

D.h.w. operation (Mini C only) Excessive temperature on primary circuit

Faulty c.h. temperature probe NTC

Faulty d.h.w temperature probe NTC (Mini C

only)

Faulty primary circuit (no water or absence of flow)

Faulty air pressure switch

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

Overheat thermostat lock out

FAULT FINDING

68 DIVERTER VALVE ACTUATOR

SPINDLE POSITION

Mini C only

To remove the diverter valve actuator refer to frame 63.

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.

Lack of power supply or fauly electronic control p.c.b. *

Faulty Electronic control/ignition p.c.b.. *

Lamp

OFF

* These conditions are normal only for a short time when the power supply is applied to the boiler.

If permanent they indicate a faulty p.c.b.

Spindle

visible

Lamp

CH mode DHW mode

Flashing lamp, alone

or simultaneously

with an other lamp.

Open circuit

Spindle fully

retracted

Flashing lamp,

alternate with

another lamp.

9,4 Kohm

Mini Installation & Servicing

bkbnbu

9,4 Kohm

bkbnbu

bn = brown

230 V

bu = blue bk = black

230 V

Open circuit

FAULT FINDING

69 F AULT FINDING

WARNING

Care must be taken when conducting fault finding tests to guard against the risk of electric shock.

230 Vac is the nominal UK supply voltage. This may vary between 253 Vac and 196 Vac.

When checking continuity ensure power is off to the appliance.

Ensure the room thermostat (if fitted) and programmer are calling for heat

Also that all services are on and the selector switch is set to heating*

FAULT FINDING

Are only the two

green leds on front

fascia flashing

together or

alternately?

yes

Are only the two green

leds on fron t fascia

flashing alternatively?

yes

With the boiler in heating

mode, what is the maximum burner

pressure with boiler and

system cool ?

(pressure values are

giveninTable2page4

Continued

from page 52.

yes yes

Does the h eating

flow pipe become

warm quickly?

yes

no no

Wait 60 se co nds

Is the gas inlet

pressure > 17 mbar?

yes

Adjust the burner

pressure. refer to

frame 29. Can the max

burner pressure* be

achieved?

Is it a system boiler?

yes

Is there a DHW tap

open?

yes

Close DHW

tap

START

Isthereatleastoneof

the led flashing?

yes

Continued on page

50 of fault finding.

Rectifygassupplyfault

Is there at least 15V dc

at the connections on

modulator coil?

yes

Adjust max ’stop’ on Gas Valvetoachievethemax

burner pressure*

Disconnect DHW

flow sensor wiring.

Does the h eating

flow pipe now

become warm?

With a fast pulse showing on LED 1 the boiler will continue to operate with a reduced performance in some fault conditions.

Before commencing fault finding please check the following:

Are all wiring connections OK ? Are the function selector settings correct (Refer to frame 29, 30 and 33)

Pay attention that if the boiler locks out five times in an hour, it is not sufficient to press the reset button to re ---start the boiler but it is necessary to disconnect the boiler from the main

supply and, after reconnect it, to press the reset button.

no no

yes

Is there 230V between

Live and Earth at the

mains connection in

the control box?

yes

Is there continuity

across the fuses on

yes

Is there 230V at the

Live connection to PCB

yes

Replace faulty PCB

Is modu lator harness

continuity O.K?

yes

Replace faulty PCB

Is there 230V between Blue and Brown at

t h e 3 --- w a y

valve

connection?

yes

Remove the motor

assembly, with 230V at

the connections is the

spindle visible? Refer

to frame 68.

the PCB?

pin 4?

Is the continuity

o f t h e 3 --- w a y valve harness

O.K?

yes

Replace faulty PCB

Rectify external

Replace faulty fuses

and check for wiring

Repair or replace

nonononono

Replace faulty

motor assembly

wiring fault

fault

wiring fault

faulty wiring

Repair or

replace

faulty

wiring

Continued on page

49 of fault finding.

Replace the DHW flow

detector sensor body. Does the heating flow

become warm?

yes

Faulty sensor now

replaced

yes

Replace faulty valve

body assembly

nono

Dismantle the DHW

detector valve. Refer to

frame 60 and clean.

W h e n r e --- a ss e m b l e d

with DHW taps closed,

does the heating flow

pipe become warm?

yes

* see Table 2 at page 4 for the correct value

Replace the faulty

DHW detector

valve

Mini --- Installation & Servicing

Continued from page

48 of fault finding

FAULT FINDING

With the boiler and

heatin g circuit warm

does the burner

pressure reduce if the

heating temperature setting is reduced to

minimum?

yes

Combination

boilers only

Continued below

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

connections on the

modulating coil?

(0=min, 16=max)

yes

Is the burner pressure

within min and max

value* with the boiler

running?

yes

Repair faulty gas

valve

no no

Is the boiler mode

setting correct?

(Refer to fr ame 56)

yes

Is the red LED

illuminated on DHW

flow sensor?

yes

Is there 230V

ac between

Blue and

Black at the

3 --- w a y v a l v e

connection?

yes

no no

Is the continuity of the

modulator harness

O.K?

yes

Adjust burner pressure.

Refer to frame 29.

Repair faulty PCB

Follow the instruction “Boiler mode setting”

(Refer to frame 56)

no no no

Is the

continuity of

t h e 3 --- w a y

valve

harness

O.K?

yes

Is there 5V dc between

Red and Blue on

connecting harness?

yes

Repair or

replace

faulty

wiring

Is the har ness

continuity O.K?

yes

Repair faulty PCB

Repair or replace

faulty wiring

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 68.

yes

Replace

faulty valve

body

assembly

Repair faulty

PCB

Replace

faulty motor

assembly

Replace the

sensor. Is

red LED

illuminated?

yes

Faul ty

sensor

now

replaced

no no

Dismantle the DHW detector

valve and clean.

Refer to frame 60.

Reassemble.

Does the DHW

water become

hot?

yes

* see Table 2 at page 4 for the correct value

Repair or

faulty DHW

detector

replace

valve

Mini Installation & Servicing

Continued from

page 48 of fault

finding. Is there at

least one of the

LEDs flashing?

FAULT FINDING

Is LED 1 flashing with

FAULT FINDING

Is the heating circuit pressurised to at least 1 bar and fully vented

Remove the pump

nut. Does the pump

rotate freely when

When the pump

runs does the

spindle of the water

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

Is there continuity

between C and NO

contacts on micro

switch when the

switch is operated?

LED 2 on ?

yes

of air?

yes

turned)

yes

Are LED2 and LED 3

flashing?

yes

Check resistance of

CH temperature probe. Is it between 12 kΩ an d 1.5 kΩ ?

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 L ED2 flashing

and LED 3 on?

yes

no no

Replace faulty

thermistor

Check resistance of

DHW temperature

probe. Is it between

12 kΩ an d 1.5 kΩ ?

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 --- Installation & Servicing

FAULT FINDING

Continued from page 50

of fault finding

Is there a burner

pressure during

ignition period?

yes

Are LED 1 and LED 3

flashing with LED 2

on, plus lockout LED

on the fascia on?

Is there > 17 mbar at

thegasvalveinlet?

Press reset button. Is

yes

there 230V across the

Brown and Blue gas

valve connection

during ignition?

Is there between 0V dc

connections on the

Is the burner pressure

within min and max

value* with the boiler

yes

and 16V dc at the

modulating coil?

(0=min, 16=max)

yes

running?

yes

Repair faulty gas

valve

nono

Rectify gas supply

fault.

no no no

Is there

230V at

Brown and

Blue at

gas valve

harness

connector

on PCB?

yes

Repair or

replace

faulty wiring

Adjust burner pressure.

Refer to frame 29.

continuity

O.K . on

yes

Replace faulty PCB

Continued on

page 53 of

fault finding

Is fuse

PCB?

Is the continuity of the

modulator harness

O.K?

yes

Repair faulty PCB

Replace

fuses

Repair or replace

faulty wiring

FAULT FINDING

Is there ignition at the

burner?

yes

Continued on page 52 of

fault finding

no no no no

Is a spark

visible at the

burner during

ignition?

yes

Is the ignition burner

pressure correct? Refer

to frame 29.

yes

Ensure the ignition electrode position and spark gaps are correct.

Are the ignition

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 43.

Are the ignition leads correctly

connected to

PCB?

yes

Replace

faulty PCB

* see Table 2 at page 4 for the correct value

Rectify

faulty

connection

Mini Installation & Servicing

Continued from page 51

of fault finding

FAULT FINDING

Is the burner light on?

yes

Does the burner

remain alight more

than 10 seconds?

yes

Can the minimum burner

pressure be achieved ?

(Pressure values are given

in Table 2 on page 4)

yes

Replace faulty PCB

Is the position of the

detection electrode

correct, and electrode

undamaged? Refer to

frame 43.

yes

Is the resistance of the

detection electrode

assembly < 5Ω from tip to

connector ?

yes

Is the polarity of

the mains correct?

Adjust the burner minimum

pressure refer to frame 29

Rectify electrode

position or replace

faulty electrode.

yes

Replace faulty detection

lead assy.

Rectify wiring fault

Connect lead correctlyIs the lead connected ?

Is the burner pressure

within min and max

value* with the boiler

running?

yes

Replace faulty PCB

Adjust burner pressure.

Refer to frame 29.

Refer back to page 48 of fault finding to continue.

* see Table 2 at page 4 for the correct value

Mini --- Installation & Servicing

Continued from page 51 of fault

finding

FAULT FINDING

Is LED 1 and LE D 2

flashing and LED 3

on?

yes

Wait for 1 minute. Is

the fan still running?

yes

Is there continuity

across C and NO on

the Air Pressure

Switch?

yes

Is LED 1 on and

LED 2 and LED 3

flashing?

yes

Has the main

overheat thermostat

operated? (Check

continuity)

yes

Allow boiler to cool

and press re--- set

no no

Is there 230V at

the fan

connections?

yes

Replace faulty fan.

Are the sensing

pipes undamaged

and connected?

yes

Istheflueclearand

venturi O.K?

yes

Is LED 1, LE D 2

and LED 3 on?

Is there continuity of

overheat thermostat

wiring at PCB

connection?

yes

Replace faulty gas

valve

Is there continuity

between NC and C at the

Air Pressure Switch?

yes

Is there continuity of the

Air Pressure Switch

harness?

yes

Replace faulty PCB

Replace sensing

pipes.

Clear flue

Repair or replace

venturi

yes

Replace faulty

Repair or replace

damaged wiring

PCB

Replace faulty Air

Pressure Switch.

Repair or replace

faulty wiring.

FAULT FINDING

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 43.

Replace faulty Air

Pressure Switch

Repair or replace

faulty wiring.

Replace faulty PCB

Mini Installation & Servicing

Continued from

page 49

Is there a temperature rise

of 35 ˚CacrosstheDHW

circuit at:

10.0 L/min 24 kW model

11.6 L/min 28 kW model

13.1 L/min 32 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

With the DHW hot

does the burner

pressure modulate if

the DHW temperature

setting is reduced to

minimum?

yes

Adjust the max setting

on the gas valve. Refer

to frame 29. Check that

max burner pressure*

can be achieved.

nono

Is the maximum water

flow correct

10.0 L/min 24 kW model

12.0 L/min 28 kW model

14.0 L/min 32 kW model

yes

no no no

Is there between 0V dc and

16V dc at the connections

on the modulating coil?

(0=min, 16=max)

yes

Is the burner pressure within

min and max value* with

the boiler running?

yes

Is the cold water supply

adequate? refer to frame

6 and Table 1 at page 4.

Check the DHW inlet

filter. Remove debris

and clean or replace

Adjust burner pressure.

Refer to frame 29.

yes

filter.

Is the continuity of the

modulator harness O.K?

yes

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 --- Installation & Servicing

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, Ideal Stelrad Group distributors and merchants.

When ordering spares please quote:

1 Boiler model (see Data Plate)

2 Appliance G.C. number (see Data Plate)

3Description

4 Quantity

5ProductNo.

Key No.

1 173 --- 148 Burner (mod. Mini C24, Mini S24) 1 075427

2 169 --- 069 Injectors for natural gas (mod. Mini C24, Mini S24) 12 075692

3 169 --- 127 Air pressure switch (mod. Mini C24, Mini S24) 1 173236

4 H 0 3 --- 7 1 3 Main heat exchanger + ’O’ rings (mod. Mini C24, Mini S24) 1 173238

5 E 9 0 --- 6 2 7 Gas valve + gaskets 1 172611

6 H 0 3 --- 6 9 9 Fan (mod. Mini C24, Mini S24) 1 173253

7 H 0 8 --- 6 0 8 Fan (mod. Mini C32) 1 173139

8 E 8 3 --- 0 1 3 Safety valve 1 172494

9 Electronic regulation p.c.b. 1 174500

10 E 0 0 --- 6 8 4 Primary circuit flow switch 1 075419

11 H3 2 --- 5 5 1 DHW flow switch (mod. Mini C24, Mini C28, Mini C32) 1 174462

12 E 0 0 --- 6 8 8 Main. flow switch membrane 1 075421

13 E 8 3 --- 1 0 1 Overheat thermostat 1 172512

14 E 5 7 --- 0 4 8 DHW heat exchanger + ’O’ rings (mod. Mini C24) 1 075460

15 H2 0 --- 9 8 7 Automatic air purger valve 1 173813

16 H2 3 --- 0 0 8 Pump + ’O’ rings 1 173778

17 E 8 3 --- 1 4 5 Temperatur e---pressure gauge 1 172551

18 E 8 3 --- 0 8 6 Three way diverter valve (electric actuator)

19 H4 4 --- 1 7 0 Fuse 3.15 AF 1 174470

20 164---026 Temperature probe (main or DHW circuit) 1 172496

21 E 8 3 --- 1 7 6 Sealed chamber gaskets kit 1 172581

22 H3 2 --- 5 5 0 Magnetic flow switch and filter (mod. Mini C24, Mini C28, Mini C32) 1 174461

23 E 8 3 --- 1 2 7 Ignition electrode --- left (mod. Mini C24, Mini S24, Mini C28, Mini S28) 1 172533

24 E 8 3 --- 1 2 6 Ignition electrode --- right (mod. Mini C24, Mini S24, Mini C28, Mini S28) 1 172532

25 E 8 3 --- 1 2 2 Detection electrode (mod. Mini C24, Mini S24, Mini C28, Mini S28) 1 172531

G.C. No Desc ription No. Off/

Boiler

173--- 149 Burner (mod. Mini C28, Mini S28) 1 075535

H 05 --- 1 8 2 Burner (mod. Mini C32) 1 173141

Injectors for natural gas (mod. Mini C28, Mini S28) 14

H 05 --- 1 8 0 Injectors for natural gas (mod.Mini C32) 16 173142

169--- 070 Injectors for LPG (mod. Mini C24, Mini S24) 12 172530

Injectors for LPG (mod. Mini C28, Mini S28) 14

H 08 --- 5 9 6 Injectors for LPG (mod.Mini C32) 16 153505

H 03 --- 6 9 1 Air pressure switch (mod. Mini C28, Mini S28) 1 173249

H 08 --- 6 0 5 Air pressure switch (mod. Mini C32) 1 173136

H 03 --- 7 1 5 Main heat exchanger + ’O’ rings (mod. Mini C28, Mini S28, Mini C32) 1 173240

H 03 --- 7 0 0 Fan (mod. Mini C28, Mini S28) 1 173254

E 5 7 --- 0 4 9 DHW heat exchanger + ’O’ rings (mod. Mini C28, Mini C32) 1 173785

1 172505

mod. Mini C24, Mini C28, Mini C32)

H 05 --- 1 8 6 Ignition electrode --- left (mod. Mini C32) 1 173502

H 05 --- 1 8 5 Ignition electrode - -- right (mod. Mini C32) 1 173501

H 05 --- 1 8 3 Detection electrode (mod. Mini C32) 1 173500

Product No.

Mini Installation & Servicing

26 E 6 9 --- 2 4 3 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 Side case panel 2 174508

30 H1 7 --- 5 6 3 Control panel door 1 173637

31 Front case panel 1 174510

1410

19 20

23 25

27 28

Mini --- Installation & Servicing

INSTALLER NOTIFICATION GUIDELINES

IT IS A REQUIREMENT OF CORGI MEMBERSHIP TO REGISTER EVERY GAS APPLIANCE

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.

Install and commission

this appliance to

manufacturers’ instructions

Complete the

Benchmark Checklist

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

CORGIwillrecordthedataandwill

send a certificate of compliance to

the property

Mini Installation & Servicing

IT IS A CONDITION OF THE

MANUFACTURERS WARRANTY

THAT THE BENCHMARK

COMMISSIONING CHECKLIST IS

FULLY COMPLETED AND LEFT

WITH THE APPLIANCE

BENCHMARKNo.

GAS BOILER COMMISSIONING CHECKLIST

BOILER SERIAL No. NOTIFICATION No.

To comp ly with the BuildingRegulations, each section must have a tickin one or other of the boxesCONTROLS

TIME& TEMPERATURECONTROL TO HEATING TIME& TEMPERATURECONTROLTO HOT WATER HEATINGZONE VALVES HOT WATER ZONE VALVES THERMOSTATICRADIATORVALVES AUTOMATIC BYPASS TOSYSTEM

ROOMT/STAT& PROGRAMMER/TIMER

CYLINDERT/STAT& PROGRAMMER/TIMER

FITTED FITTED NOT REQUIRED FITTED FITTED NOT REQUIRED

PROGRAMMABLE RO OMSTAT

FOR ALL BOILERS CONFIRM THE FOLLOWING

THE SYSTEM HAS BEEN FLUSHED IN ACCORDANCE WITH THEBOILER MANUFACTURER’SINSTRUCTIONS ? THE SYSTEM CLEANER USED THE INHIBITORUSED

FOR THE CENTRALHEATING MODE,MEASURE& RECORD

GASRATE BURNER O PERATING PRESSURE(IF APPLICABLE) CENTRALHEATINGFLOWTEMPERATURE CENTRALHEATINGRETURN TEMPERATURE

FOR COMBINATION BOILERSONLY

COMBIBOILER

NOT REQUIRED

m3/hr ft/hr N/A mbar

°C °C

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

YES NO

FOR THE DOMESTIC HOT WATER MODE,MEASURE & RECORD

GASRATE MAXIMUMBURNER OPERATINGPRESSURE (IF APPLICABLE) COLDWATERINLETTEMPERATURE HOT WATER OUTLET TEMPERATURE WATER FLOW RATE lts/min

m3/hr ft/hr N/A mbar

FOR CONDENSINGBOILERSONLYCONFIRM THE FOLLOWING

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

YES

FOR ALL INSTALLATIONS CONFIRM THE FOLLOWING

THE HEATING AND HOT WATER SYSTEM COMPLIES WITHPARTS4&7OFTHEBUILDINGREGULATIONS

THE APPLIANCE AND ASSOCIATEDEQUIPMENT HAS BEEN INSTALLED AND COMMISSIONED IN ACCORDANCE WITHTHE MANUFACTURER’SINSTRUCTIONS

IFREQUIRED BYTHE MANUFACTURER,HAVEYOU RECORDED A CO/CO2RATIOREADING? CO/CO2RATIOYESN/A THE OPERATIONOF THE APPLIANCEAND SYSTEM

CONTROLS HAVEBEEN DEMONSTRATEDTO THE CUSTOMER

°C °C

THE MANUFACTURER’SLITERATURE HAS BEEN LEFT WITH THE CUSTOMER

COMMISSIONING ENG’SNAME

PRINT CORGI ID No. SIGN DATE

SERVICE INTERVAL RECORD

Itis recommended that your heatingsystemis serviced regularly

and thatyou complete the appropriate Service IntervalRecord Below.

ServiceProvider.Before completing theappropriateService IntervalRecord below,please ensure you have carried outtheservice

as described intheboiler manufacturer’s instructions.Always use the manufacturer’sspecifiedspare part when replacing all controls

SERVICE1

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

SIGNATURE

SERVICE3

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

SIGNATURE

SERVICE5

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

DATE

SERVICE2

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

SIGNATURE

SERVICE4

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

SIGNATURE

SERVICE6

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

DATE

SIGNATURE

SERVICE7

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

SIGNATURE

SERVICE9

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

SIGNATURE

DATE

SIGNATURE

SERVICE8

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

SIGNATURE

SERVICE10

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

SIGNATURE

DATE

Technical Training

The Ideal Boilers T echnical 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

thecodeofpracticefortheinstallation

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

Ideal Stelrad Group 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

ideal Mini C24 User guide

Specifications and Main Features

Frequently Asked Questions

User Manual