ideal Mini HE C24 User guide

Page 1
installation and servicing
mini HE
Your Ideal installation and servicing guide
For details of document amendments, refer to page 3
C24,C28
When replacing any part of this appliance, use only spare parts that you can be assured conform to safety and performance specification that we require. Do not use reconditioned or copy parts that have not been clearly authorised by Ideal Boilers
17962.1138.1 0406 64A4 GB
*1796211381*
For the very latest copy of literature for specification purposes please visit our website www.idealboilers.com where you will be able to download the relevant information in pdf format.
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mini HE --- Installation & Servicing
Page 3
DOCUMENT AMENDMENTS
Relevant Installation changes implemented in this book from Mod Level.............4905 to 0406
F Pages 33 and 37
Amendment to the illustration of the air pressure switch connection
Caradon Ideal Limited reserve the right to vary specification without notice
mini HE --- Installation & Servicing
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Page 4
GENERAL
Table 1 --- Boiler Data
mini HE C24 mini HE C28
Gas supply type & connection II
Inlet / Outlet connection --- Domestic Hot Water 15 mm copper
Flow & return connection --- Central Heating 22 mm copper
Flue terminal diameter mm (in.) 100 (4)
Max working pressure (sealed system) bar (lb/in2) 3.0 (43.5)
Max DHW water inlet pressure bar (lb/in2) 10.0 (145.0)
Min DHW water inlet pressure bar (lb/in2) 0.3 (4.4)
Electrical supply 230 Vac 50 Hz
Max power consumption W 140 150
External fuse rating 3 A
Internal fuse rating T 2A
Water content --- CH litre (gal.) 2.1 (0.46) 2.2 (0.48)
Water content --- DHW litre (gal.) 0.2 (0.044)
Dry weight kg (lb.) 42.5 (93.7) 44.5 (98.1)
Size: Height / Width / Depth mm (in.) 803 (31 5/8”) / 400 (15 3/4”) / 345 (13 9/16”)
Lift weight kg (lb.) 37.5 (82.7) 39.5 (87.1)
Table 2 --- Performance Data --- Central Heating
mini HE C24 mini HE C28
Max Min Max Min
Burner pressure (Hot) G20
G31
Input based on nett CV kW (btu/h) 25.0 (85 295) 11.0 (37 530) 29.0 (98 942) 13.0 (44 353)
Input based on gross CV kW (btu/h) 27.7 (94 516) 12.2 (41 628) 32.2 (109 871) 14.4 (49 135)
Output Non Condensing G20
G31
Output Condensing G20
G31
Gas consumption (Hot) G20
G31
Seasonal efficiency* G20
G31
NOx classification Class 2
mbar (in.w.g.) 10.8 (4.3)
kW (btu/h) 24.6 (83 973)
kW (btu/h) 26.6 (90 754)
l/s (ft3/h) l/s
(SEDBUK) % Band B 87.7
35.5 (14.2)
23.7 (80 894)
26.6 (90 754)
0.74 (93.6)
0.30
Band B 86.9
*The value is used in the UK Government’s Standard Assessment Procedure (SAP) for energy rating of dwellings. The test data from which it has been calculated have been certified by a notified body.
Table 3 --- Performance Data --- Domestic Hot Water
mini HE C24 mini HE C28
Burner pressure (Hot) G20
G31
Input based on nett CV kW (btu/h) 25.0 (85 295) 29.0 (98 942)
Input based on gross CV kW (btu/h) 27.7 (94 516) 32.2 (109 871)
Output Non Condensing G20
G31
Output Condensing G20
G31
Gas consumption (Hot) G20
G31
Flow 35 ° C temp. rise l/m (gpm) 10.1 (2.2) 11.7 (2.6)
Domestic hot water specific rate l/m (gpm) 11.9 (2.6) 13.9 (3.1)
Note: the gas consumption is calculated using a calorific
mbar (in.w.g.) 10.8 (4.3)
kW (btu/h) 24.6 (83 973)
kW (btu/h) 26.6 (90 754)
l/s (ft3/h) l/s
35.5 (14.2)
23.7 (80 894)
26.6 (90 754)
0.74 (93.6)
Key to Symbols:
value of 38.7 MJ/m3(1038 Btu/ft3) gross or 34.9 MJ/m3(935 Btu/ft3) nett.
To obtain the gas consumption at different calorific value: ---
a. FOR L/S --- divide the gross heat input (kW) by the gross C.V. of the gas (MJ/m3)
b. FOR FT3/H --- divide the gross heat input (Btu/h) by the gross C.V. of the gas (Btu/ft3)
IE = Ireland, GB = United Kingdom (Countries of destination) PMS = Maximum operating pressure of water C12C32C42= a room sealed appliance designed for connection via concentric ducts to a horizontal or vertical terminal or twin flue system.
II
H or 3rd family gas group 3P
G20 20mbar, G31 37mbar, 22 mm copper
2H3P
1.5 (0.6)
7.7 (3.1)
10.2 (34 936)
10.2 (34 936)
11.1 (37 871)
10.8 (36 997)
0.32 (40.9)
0.13
Maximum
0.30
= appliance designed for use on 2nd family gas group
2H3P
10.0 (4.0)
36.0 (14.4)
28.3 (96 488)
27.4 (93 599)
30.7 (104 602)
30.7 (104 602)
0.85 (108.4)
0.34
Band B 87.5 Band B 87.0
28.3 (96 488)
27.4 (93 599)
30.7 (104 602)
30.7 (104 602)
0.85 (108.4)
1.6 (0.6)
7.7 (3.1)
12.1 (41 284)
12.1 (41 284)
13.2 (44 965)
12.9 (44 016)
0.35 (45.2)
10.0 (4.0)
36.0 (14.4)
0.34
0.14
CAUTION. To avoid the possibility of injury during the installation, servicing or cleaning
of this appliance care should be taken handling edges of sheet steel components.
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mini HE --- Installation & Servicing
Page 5
GENERAL
mini HE
Boiler size G.C. appliance No. PI No.
(Benchmark No.)
mini HE C24 47 ---348 ---38 0694BP0384 mini HE C28 47 ---348 ---39 0694BP0384
Destination countries: GB, IE
CONTENTS
Air supply 9
Benchmark Commissioning Checklist 58
Boiler clearances 6
Boiler exploded view 14
Electrical connections 20
Electrical supply 10
Fault finding 48
Flow wiring diagram 24
Flue fitting 16
Gas conversion 29
Gas safety regulations 7
Gas supply 8
Installation 15
Mandatory requirements 7
Replacement of components 34
Safe handling 7
Servicing 30
Short list of parts 55
Thermostatic radiator valves 12
Water connections 19
Water treatment 9
Wiring diagrams 22
For GB, to comply with Building Regulations Part L1 (Part J in Scotland) the boiler should be fitted in accordance with the manufacturer’s instructions. Self--- certification that the boiler has been installed to comply with Building Regulations can be demonstrated by completing and signing the Benchmark Commissioning Checklist.
BENCHMARK COMMISSIONING CHECKLIST DETAILS
Boiler Page
Make and model 5
Appliance serial no. on data badge 14
SEDBUK No. % 4
Controls
Time and temperature control to heating 26
Time and temperature control to hot water 26
Heating zone valves 26
TRV’s 12
Auto bypass 12
Boiler interlock 12
For all boilers
Flushing to BS.7593 9
Inhibitor 9
Central heating mode
Heat input to be calculated
Boiler Page
Burner operating pressure measure and record Central heating flow temp. measure and record Central heating return temp. measure and record
For combination boilers only
Scale reducer 12 Hot water mode Heat input to be calculated Max. operating burner pressure measure and record Max. operating water pressure measure and record Cold water inlet temp measure and record Hot water outlet temp. measure and record Water flow rate at max. setting measure and record
For condensing boilers only
Condensate drain 20 For all boilers: complete, sign & hand over to customer For assistance see Technical Helpline on the back page
NOTE TO THE INSTALLER: COMPLETE
THE BENCHMARK COMMISSIONING
CHECKLIST AND LEAVE THESE
INSTRUCTIONS WITH APPLIANCE
mini HE --- Installation & Servicing
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Page 6
GENERAL
1 BOILER WATER CONNECTION
400
31
50
35
803
700
257
16
Wall
mounting
Plate
Condensate
drain
connection
area
Pipe size O.D. mm
CH flow 22
CH return 22
Gas inlet 22
DHW cold inlet 15
DHW hot outlet 15
83 (3 1/4”)
52 (2”)
65 (2 9/16”)
CH flow
DHW hot outlet *
65 (2 9/16”)
64 (2 1/2”)
Gas inlet
CH return
DHW cold inlet *
2 BOILER CLEARANCES
All dimensions in mm (in.)
The following minimum clearances must be maintained for operation and servicing. Additional space will be required for installation, depending upon site conditions.
200 (7 7/8”)
25 (1”) 50 (2”)
Side and Rear Flue
a. Provided that the flue hole is cut accurately, e.g. with a core
drill, the flue can be installed from inside the building where wall thickness does not exceed 600 mm (24”).
Where the space into which the boiler is going to be installed is less than the length of flue required the flue must be fitted from the outside.
installation from inside ONLY
b. If a core boring tool is to be used inside the building the
space in which the boiler is to be installed must be at least wide enough to accommodate the tool.
273 (10 3/4”) 127 (5”)
190 (7 1/2”)
200 (7 7/8”)
Bottom clearance
The bottom clearance, after installation, can be reduced to 20mm. However, 200mm must be available for servicing.
Front clearance
The minimum front clearance when built into a cupboard is 50mm (2”) from the cupboard door. However 450mm (17 3/4”) overall clearance is still required, with the cupboard door open, to allow for servicing.
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95 ()
mini HE --- Installation & Servicing
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GENERAL
INTRODUCTION
mini HE C24 and mini HE C28 are wall mounted, low water
content, balanced flue, condensing combination gas boilers.
Central heating (CH) output and domestic hot water (DHW) output are both fully modulating:
--- between 10.2 (34 936) and 24.6* (83 973) kW (btu/h) for
model mini HE C24;
--- between 12.1 (41 284) and 28.3* (96 488) kW (btu/h) for
model mini HE C28.
* ouputs with G31 (propane) feeding are sligthly different. See section Boiler Data at page 4 for detailed figures.
Due to the high efficiency of the boiler a plume of water vapour will form at the terminal during operation.
The boilers are suitable for connection to fully pumped, pressurised sealed water systems ONLY.
A system bypass is not required when TRV’ s are fitted to all radiators (see Frame 5). The boiler incorporates an automatic bypass.
A circulating pump, pressure gauge, safety valve and heating expansion vessel are provided.
The CH flow temperature is controlled by a thermistor. In DHW mode the boiler modulates to sustain a nominal adjustable water flow temperature of 55 ° C.
The boiler casing is of white painted mild steel with a drop---down controls access door.
The boiler temperature control is located behind the control panel door.
The main heat exchanger is made of copper.
The condensing heat exchanger (recuperator) and the DHW heat exchanger are stainless steel.
The system pipework must include drain cocks in appropriate places. Pipework may be taken downwards.
For upwards pipework installation an additional frame (optional) must be used (see frame 18).
OPTIONAL EXTRA KITS
Programmer Kit fits neatly within the casing. Separate fitting instructions are included with the kit. Note. If using an alternative programmer read Frame 25 first.
Horizontal Concentric Extension Ducts
Up to 2,7 m (8’ 10”) for all models.
Other available kits are listed in frame 9.
SAFE HANDLING
This boiler may require 2 or more operatives to move it to its installation site, remove it from its packaging base and during movement into its installation location. Maneuvering the boiler may include the use of a sack truck and involve lifting, pushing and pulling.
Caution should be exercised during these operations.
Operatives should be knowledgeable in handling techniques when performing these tasks and the following precautions should be considered:
F Grip the boiler at the base. F Be physically capable. F Use PPE as appropriate, e.g. gloves, safety footwear.
During all maneuvers and handling actions, every attempt should be made to ensure the following unless unavoidable and/or the weight is light.
F Keep back straight. F Avoid twisting at the waist.
mini HE --- Installation & Servicing
F Avoid upper body/top heavy bending. F Always grip with the palm of the hand. F Use designated hand holds. F Keep load as dose to the body as possible. F Always use assistance if required.
DHW OPERATION
With no call for CH the boiler fires only when DHW is drawn off. When there is a call for CH, the heating system is supplied at the selected temperature until DHW is drawn off. The output is then directed by the diverter valve to heat the secondary heat exchanger and supply a maximum draw--- off of:
mini HE C24. 10.1 (2.2) l/min (gpm) at 35 degree rise.
mini HE C28 11.7 (2.6) l/min (gpm) at 35 degree rise.
The nominal DHW temperature is 55 ° C, but water drawn off when the boiler has been on for central heating may be hotter than this, for a short period of time.
GAS SAFETY
Current Gas Safety (Installation and Use) Regulations or rules in force
The appliance is suitable only for installation in GB and IE and should be installed in accordance with the rules in force. In GB, the installation must be carried out by a CORGI Registered Installer. It must be carried out in accordance with the relevant requirements of the:
F Gas Safety (Installation and Use) Regulations F The appropriate Building Regulations either The Building
Regulations, The Building Regulations (Scotland), Building Regulations (Northern Ireland).
F The Water Fittings Regulations or Water byelaws in
Scotland.
F The Current I.E.E. Wiring Regulations.
Where no specific instructions are given, reference should be made to the relevant British Standard Code of Practice.
In IE, the installation must be carried out by a Competent Person and installed in accordance with the current edition of I.S.813 ”Domestic Gas Installations”, the current Building Regulations and reference should be made to the current ETCI rules for electrical installation.
Detailed recommendations are contained in the following British Standard Codes of Practice:
BS 5440:1 Flues (for gas appliances of rated input not
exceeding 70 kW).
BS 5440:2 Ventilation (for gas appliances of rated input
not exceeding 70 kW).
BS. 5449 Forced circulation hot water systems.
BS. 5546 Installation of gas hot water supplies for
domestic purposes (2nd Family Gases)
BS 6700 Design, installation testing and maintenance of
services supplying hot water for domestic use.
BS. 6798 Installation of gas fired hot water boilers of
rated input not exceeding 70 kW.
BS. 6891 Low pressure installation pipes.
Health & Safety Document No. 635.
The Electricity at Work Regulations, 1989.
The manufacturers notes must NOT be taken, in any way, as overriding statutory obligations.
IMPORTANT These appliances are CE certificated for safety and performance. It is, therefore, important that no external control devices, e.g. flue dampers, economisers etc., are directly connected to these appliances unless covered by
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GENERAL
these Installation and Servicing Instructions or as otherwise recommended by Caradon Ideal Ltd. in writing. If in doubt please enquire.
Any direct connection of a control device not approved by Caradon Ideal Ltd. could invalidate the certification and the normal appliance warranty. It could also infringe the Gas Safety Regulations and the above regulations.
SAFE HANDLING OF SUBSTANCES
Care should be taken when handling the boiler insulation panels, which can cause irritation to the skin. No asbestos, mercury or CFCs are included in any part of the boiler in its manufacture.
LOCATION OF BOILER AND FLUE OUTLET
The boiler must be installed on a flat and vertical wall, capable of adequately supporting the weight of the boiler and any ancillary equipment.
The boiler may be fitted on a combustible wall and insulation between the wall and the boiler is not necessary, unless required by the local authority.
The boiler must not be fitted outside.
Timber Framed Buildings
If the boiler is to be fitted in a timber framed building it should be fitted in accordance with the Institute of Gas Engineers document IGE/UP/7, 1998.
Bathroom Installations
The boiler may be installed in any room or internal space, although particular attention is drawn to the requirements of the current I.E.E. (BS.7671) Wiring Regulations and, in Scotland, the electrical provisions of the building regulations applicable in Scotland with respect to the installation of the boiler in a room or internal space containing a bath or shower.
For Ireland reference should be made to the current ETCI rules for electrical installations and I.S.813:2002
Where a room sealed appliance is installed in a room containing a bath or shower then the appliance and any electrical switch or appliance control utilising mains electricity should be so situated that it cannot be touched by a person using the bath or shower.
Note. It is not permissible to install a mains socket in a bathroom.
Where installation will be in an unusual location, special procedures may be necessary and BS 6798 gives detailed guidance on this aspect.
Compartment Installations
A compartment used to enclose the boiler should be designed and constructed specially for this purpose. An existing cupboard or compartment may be used, provided that it is modified for the purpose.
In both cases details of essential features of cupboard / compartment design, including air cupboard installation, are to conform to the following:
F BS 6798 (No cupboard ventilation is required --- see “Air
supply” for details)
F The position selected for installation MUST allow
adequate space for servicing in front of the boiler.
F For the minimum clearances required for safety and
subsequent service, see the wall mounting template and frame 2. In addition, sufficient space may be required to allow lifting access to the wall mounting plate.
8
GAS SUPPLY
The local gas supplier should be consulted, at the installation stage, in order to establish the availability of an adequate supply of gas. An existing service pipe must NOT be used without prior consultation with the local gas supplier. Natural gas boilers must be installed on a gas supply with a governed meter. A gas meter can only be connected by the local gas supplier or by a registered CORGI engineer.
Propane gas boilers MUST be installed with pipes, cylinders and pressure regulators fitted in accordance with BS.5482.1. Bulk tank installations MUST comply with the Home Office code of practice for storage of liquefied petroleum gas at fixed installations. The complete installation MUST be tested for gas soundness and purged as described in the above code.
The boiler is adjusted at the factory for use with the relevant supply gas. A working gas pressure equal to that stated in Table 1 MUST be available at the boiler inlet.
Where applicable, the appliance can be converted for G20--- Natural Gas or G31--- Propane Gas by using the appropriate conversion kit.
IMPORTANT Installation pipes MUST be fitted in accordance with BS. 6891. In IE refer to I.S. 813.2002. Pipework from the meter to the boiler MUST be of an adequate size, i.e. not less than 22 mm O.D. copper or 3/4” BSP iron.
FLUE INSTALLATION REQUIREMENTS
The flue must be installed in accordance with the recommendations of BS. 5440---1 2000. In IE refer to I.S. 813.2002.
The following notes are intended for general guidance.
1 The boiler MUST be installed so that the terminal is
exposed to external air.
2 It is important that the position of the terminal allows the
free passage of air across it at all times.
3 Minimum acceptable spacing from the terminal to
obstructions and ventilation openings are specified in Table 4.
4 Where the lowest part of the terminal is fitted less than 2m
(6’6”) above a balcony, above ground or above a flat roof to which people have access then the terminal MUST be protected by a purpose designed guard. Ensure that the guard is fitted centrally.
5 Where the terminal is fitted within 850mm (34”) of a plastic
or painted gutter or 450mm (18”) of painted eaves then an aluminium shield at least 750mm (30”) long should be fitted to the underside of the gutter or painted surface fitted centrally above the flue.
6 The air inlet/products outlet duct and the terminal of the
boiler MUST NOT be closer than 25mm (1”) to combustible material. Detailed recommendations on the protection of combustible material are given in BS. 5440--- 1:2000. In IE refer to I.S. 813.2002.
Table 4 --- Balanced flue terminal position
Terminal position
1 Directly below, above or along side
of an openable window, air vent or other ventilation opening
2 Below guttering, drain pipes or soil
pipes
3 Below eaves 25 mm ( 1”)
4 Below balconies or a car port roof 25 mm ( 1”)
5 From vertical drain pipes or soil
pipes*
6 From an internal or external corner
or to a boundary along side the terminal
Minimum spacing
300 mm (12”)
25 mm ( 1”)
25 mm ( 1”)
25 mm ( 1”)
mini HE --- Installation & Servicing
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GENERAL
7 Above adjacent ground, roof or
balcony level
8 From a surface or a boundary
facing the terminal.
9 From a terminal facing a terminal 1200 mm (48”)
10 From an opening in a car port (e.g.
door or window) into dwelling
11 Vertically from a terminal on the
same wall
12 Horizontally from a terminal on the
wall
* If the terminal is within 150mm of any vertical soil or drain pipe, an aluminium shield at least 400mm (15 3/4”) long should be fitted equi--- distant from the terminal and close to the pipe.
Vertical Terminals
13 Above the roof pitch with roof
slope of all angles.
Above flat roof
14 From single wall face
From corner wall faces
Twin Flue Applications
15 Centre distance between air inlet
and flue outlet ducts
** Where the twin flue ducts are positioned at or near the above minimum centres the wall sealing gaskets should be trimmed to allow them to fit flat to the wall. This should be done for both in­side and outside wall gaskets
Terminals guards are available from boiler suppliers --- ask for Tower Flue Guard, Model K6. In case of difficulty seek advice from:
Grasslin UK Ltd.,Tower house, Vale Rise, Tonbridge, Kent TN9 1TB Tel. +44 (0) 1732 359 888 Fax No. +44 (0) 1732 354 455 www.tfc--- group.co.uk
IMPORTANT It is absolutely ESSENTIAL to ensure, in practice, that products of combustion discharging from the terminal cannot re --- enter the building or any other adjacent building through ventilators, windows, doors other sources of natural air infiltration, or forced ventilation / air conditioning.
If this should occur the appliance MUST be turned OFF, labelled as “unsafe” until corrective action taken.
300 mm (12”)
600 mm (24”)
1200 mm (48”)
1500 mm (60”)
300 mm (12”)
300 mm (12”)
300 mm (12”)
600 mm (24”)
1000 mm (40”)
120mm (5”) **
AIR SUPPLY
It is NOT necessary to have a purpose--- provided air vent in the room or internal space in which the boiler is installed. Neither is it necessary to ventilate a cupboard or compartment in which the boiler is installed, due to the low surface temperatures of the boiler casing during operation; therefore the requirements of BS6798, Clause 12, BS 5440:2 and in IE I.S. 813:2002 may be disregarded.
WATER CIRCULATION SYSTEM
The boilers are designed for connection to pressurised, fully pumped, sealed water central heating systems ONLY. The domestic hot water (DHW) calorifier is incorporated within the combi boiler and only requires connection to the mains water supply.
Additional Pumps.
The boiler is supplied with an integral circulating pump. If the boiler is to be used in conjunction with any additional circulating pumps, please contact the Technical Helpline for advice on application.
IMPORTANT
A minimum length of 1m of copper pipe MUST be fitted to both flow and return connections from the boiler before connection to any plastic piping.
Ensure that the mains water supply pressure is adequate to provide the required DHW flow rate. Refer to Table 1 on page 4.
The central heating system should be in accordance with BS. 6798 and, in addition, for smallbore and microbore systems BS. 5449.
The domestic hot water system should be in accordance with BS. 5546 and BS. 6700.
Copper tubing to BS 2871:1 is recommended for water carrying pipework and MUST be used for pipework carrying potable water.
Any soldered joints on potable water pipework MUST NOT be made with solder containing lead.
Ancillary pipework not forming part of the useful heating surface should be lagged to prevent heat loss and any possible freezing --- particularly where pipes run through roof spaces or ventilated underfloor spaces.
Draining taps should be at least 1/2” BSP nominal size and be in accordance with BS 2879.
WATER TREATMENT
Central Heating
Antifreeze fluid, corrosion and scale inhibitor fluids suitable for use with boilers having copper heat exchangers may be used in the central heating system.
IMPORTANT
The application of any other treatment to this product may render the guarantee of Caradon Ideal Limited INVALID.
Caradon Ideal Limited recommend Water Treatment in accordance with the Benchmark Guidance Notes on Water Treatment in Central Heating Systems.
Caradon Ideal Limited recommend the use of Fernox, GE Betz Sentinel or Salamander water treatment products, which must be used in accordance with the manufacturers instructions.
Notes.
1. It is most important that the correct concentration of the water treatment products is maintained in accordance with the manufacturers’ instructions.
2. If the boiler is installed in an existing system any unsuitable additives MUST be removed by thorough cleansing. BS 7593:1992 details the steps necessary to clean a domestic heating system.
3. In hard water areas, treatment to prevent lime scale may be necessary --- however, the use of artificially softened water is NOT permitted.
4. Under no circumstances should the boiler be fired before the system has been thoroughly flushed.
mini HE --- Installation & Servicing
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GENERAL
Domestic Hot Water
In hard water areas where mains water can exceed 200ppm Total Hardness (as defined by BS 7593:1993 Table 2) a scale reducing device should be fitted into the boiler cold supply within the requirements of the local water company. The use of artificially softened water, however, is NOT permitted.
Caradon Ideal Limited recommend the use of Fernox Qantomat, GE Betz Sentinel Combiguard and Calmag CalPhos I scale reducing devices, which must be used in accordance with the manufacturers’ instructions.
For further information contact:
3 ELECTRICAL SUPPLY
Warning. This appliance must be efficiently earthed.
Wiring external to the appliance MUST be in accordance with the current I.E.E. (BS.7671) Wiring Regulations and any local regulations which apply. For Ireland reference should be made to the current ETCI rules for electrical installations.
Fernox Cookson Electronics Forsyth Road Sheerwater Woking Surrey GU21 5RZ +44 (0) 1799 550811
Salamander (Eng) Ltd Reddicap Trading Estate Sutton Coldfield West Midlands B75 7BY
+44 (0) 121 378 0952
The point of connection to the mains should be readily accessible and adjacent to the boiler, except for bathroom installations where the point of connection to the mains MUST be situated outside of the bathroom.
Note. Where a room sealed appliance is installed in a room containing a bath or shower then the appliance and any electrical switch or appliance control utilising mains electricity should be so situated that it cannot be touched by a person using the bath or shower.
Calmag Ltd. Unit 4---6 Crown Works Bradford Road Sandbeds Keighley West Yorkshire BD20 5LN +44 (0) 1535 210320
GE Betz Sentinel Division Foundry Lane Widnes Cheshire WA8 8UD
+44 (0) 151 420 9563
4 SEALED SYSTEM REQUIREMENTS
Central Heating
Note. mini HE boilers are suitable for fully pumped pressurised sealed systems only.
REQUIREMENTS
1 General
The installation must comply with the requirements of BS. 6798 and BS. 5449.
2 Flow Temperature
The installation should be designed to work with flow temperatures of up to 90 °C.
3 Working Pressure
All components of the system must be suitable for a working pressure of 3 bar (45 lb/in2) and temperature of 110 ° C. Extra care should be taken in making all connections so that the risk of leakage is minimised.
The following components are incorporated within the appliance:
a. Circulating pump.
b. Safety valve; with a non--- adjustable pre--- set lift pressure of 3 bar (45lb/in2).
c. Pressure gauge; covering a range of 0--- 4 bar.
d. 6 litre expansion vessel; with an initial charge pressure of
0.7 bar (10.5 lb/in2).
For further details refer to BS.5449:1 and the British Gas Corporation publication ’Specifications for Domestic Central Heating and Hot Water’.
10
4 Filling the system
Fill the system through a temporary hose connection from a draw---off tap supplied from a service pipe under mains pressure. Where the mains pressure is excessive a pressure reducing valve shall be used to facilitate filling.
When installing the filling connection provided with the boiler an additional WRAS approved valve must be fitted to the mains water supply upstream of the double check valve to fully comply the Water Regulations
Stop valve Additional stop valve
CH return
Temporary hose (disconnect after filling)
System filling and make ---up
Proceed with the following:
F Thoroughly flush out the whole of the system with cold
water before fitting the boiler.
F Fill and vent the system until the pressure gauge registers
1.5 bar (22 lb/in2). Examine for leaks.
F Release water from the system until a pressure of 1 bar
(15 lb/in2) is reached.
To avoid getting debris on the valve seat, do not use the safety valve to do this.
F Light the boiler and heat the system to the maximum
working temperature. Examine for leaks.
F Turn off the boiler and drain the system while still hot. F Refill and vent the system. F Re --- pressurise the system to the desired charge pressure
(see Table 5).
Hose unions
Mains Water Supply
Double check valve assembly Note direction of flow
mini HE --- Installation & Servicing
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GENERAL
mH2
O
Table 5
System charge pressure (bar)
Safety valve setting 3.0
Vessel pre--- charge pressure (bar)
System volume (litres) Volume of expansion vessel
75 --- --- ---
100 0.3 0.8 1.4
125 1.8 2.5 3.2
150 3.4 4.2 5.0
175 5.0 6.0 7.0
200 6.5 7.6 8.7
225 8.1 9.3 10.6
250 9.6 11.1 12.4
275 11.2 12.8 14.3
300 12.8 14.5 16.1
Multiply this factor by system volume and deduct 6 litres to obtain size of additional vessel for other system volumes.
0.5 0.7 1.0
0.7
in addition to 6 litre unit
fitted to boiler
0.063 0.069 0.074
5 Size of expansion vessel
For the system water expansion to be contained by the 6 litre expansion vessel the cold system volume must not exceed:
96 litres when pressurised to 0.5 bar (cold)
88 litres when pressurised to 0.7 bar (cold)
81 litres when pressurised to 1.0 bar (cold)
If the pressure exceeds 2.65 bar when the boiler is up to temperature with all radiators in use then an additional expansion vessel MUST be installed on the return pipework.
For expansion volumes see Table 5.
Guidance on vessel sizing is given in BS 7074:1 and BS 5449
For IE refer to the current edition of I.S. 813.
6 Hydraulic Loss Remaining pump capacity
6
5
4
3
2
1
0
0 200 400 600 800 1000 1200 1400
Flow rate l/hour
7 Draining the system
Draining taps MUST be located in accessible positions to permit the draining of the whole central heating system, including the central heating side of the boiler. The taps should be at least 1/2” BSP nominal size and be in accordance with BS 2879.
mini HE --- Installation & Servicing
11
Page 12
GENERAL
5 BOILER CONTROL INTERLOCKS
Thermostatic radiator valves.
Caradon Ideal Ltd. support the recommendations made by
leading manufacturers of domestic heating controls that heating systems utilising full thermostatic radiator valve control of temperature in individual rooms should also be fitted with a room thermostat controlling the temperature in a space served by radiators not fitted with such a valve as stated in BS5449. Such an arrangement will provide for a more efficient control of the environment and will also avoid the continuous running of the circulation pump during programmed heating ON periods, saving electrical energy.
It is therefore strongly recommended that, when thermostatic radiator valves are used, the space heating temperature control over a living/dining area or a hallway, having a heat requirement of at least 10% of the boiler output, is achieved using a room thermostat whilst other rooms are individually controlled by thermostatic radiator valves as stated in BS5449.
6 DOMESTIC HOT WATER
REQUIREMENTS
1 The domestic hot water service must be in accordance
with BS 5546 and BS 6700.
2 For the minimum and maximum working pressures of the
mini HE C24 and mini HE C28 domestic hot water circuit refer to Table 1, page 4.
3 The cold water supply pipe should be flushed before
fitting the boiler.
4 The boilers are suitable for connection to most types of
washing machine and dishwashing appliances.
For further information refer to “Good Practise Guide 143” a publication of the energy efficiency office, available from the building research establishment Garston Watford WD2 7JR tel: +44 (0) 1923 664258
The boiler is fitted with an automatic internal bypass. No further system bypass is required.
Typical installation
TRV
TRV
TRV
A
D
5 When connecting to suitable showers, i.e. those designed
for modulating domestic hot water, ensure that:
a. The cold inlet to the boiler is fitted with an approved
anti---vacuum or syphon non--- return valve.
b. Hot and cold supplies are of equal pressure.
6 Hard water areas
In areas where the water is ’hard’ it is recommended that a proprietary scale---reducing device is fitted into the boiler cold supply, within the requirements of the local water company.
Room T/stat
B
Balancing valve
12
mini HE --- Installation & Servicing
Page 13
GENERAL
7 BOILER WATER CIRCUIT DIAGRAM
35
34
23
21
20
19
18
36
37
15
16
13
26
14
12
10
6
11
17
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
24
25
22
27
1
33
28
29
30
31
8
9
5
2
7
7 Central heating flow cock 8 By ---pass valve 9 Central heating (CH) return cock 10 3 bar pressure relief valve 11 Gas cock 12 Expansion vessel 13 Gas valve inlet pressure tap 14 Modulating gas valve 15 Burner pressure tap 16 Flame detection electrode 17 Ignition electrodes 18 Burner 19 Combustion chamber 20 Primary heat exchanger 21 Fan 22 Air pressure switch 23 Venturi device 24 Flue outlet pipe 25 Air intake pipe 26 Automatic air vent 27 Overheat thermostat
32
28 Pump 29 Pump vent plug
34
30 Water circuit temperature probe 31 CH flow switch 32 DHW temperature probe 33 CH circuit temperature/pressure gauge 34 Recuperator 35 Flue thermostat 36 Condensate trap 37 Condensate drain pipe
mini HE --- Installation & Servicing
13
Page 14
8 BOILER ASSEMBLY ---
Exploded View
39
INSTALLATION
38
37
36
40
41
INSTALLATION
1
2
3
4
5
6
35
34
33
32
31
30
29
28
27
26
25
24
7
8
9 10 11
12
13
14
15
16
23 21
1 Air pressure switch
2 Recuperator
3 Condensate trap
4 Overheat thermostat
5 Condensing to main heat
exchanger connection pipe
6 Primary heat exchanger
7 Inner case cover
8 Flame detection electrode
9 Ignition electrodes
10 Heat exchanger return pipe
11 Auto air vent
12 Main circuit drainage cock
13 Pump
14
20
1922
14 DHW flow switch
15 DHW Thermistor
16 Ignition pcb
17 Right hand panel
18 Boiler front panel
19 Appliance data badge (inside)
20 Left hand panel
21 CH circuit pressure gauge
22 Model identification & instructions
23 Control panel door
24 Main control pcb
25 CH Thermistor
26 CH flow switch
27 Heat exchanger flow pipe
18
17
28 Return manifold
29 3 way diverter valve
30 DHW heat exchanger
31 Bypass pipe
32 3 bar pressure relief valve
33 Gas valve
34 Gas valve outlet pipe
35 Injector manifold
36 Burner
37 Flue hood
38 Fan
39 Expansion vessel
40 Venturi
41 Flue thermostst
mini HE --- Installation & Servicing
Page 15
INSTALLATION
9 UNPACKING
The boiler is supplied fully assembled in one pack A, together with a standard flue assembly for lengths up to 960 mm (37” 3/4), rear or side flue outlet, in pack B.
Unpack and check the contents.
Pack A contents
A The boiler.
B Hardware pack
C Wall mounting plate
D Wall mounting template
E User’s, Installation & Servicing instructions.
F Filling loop assembly
A
B
E
Hardware pack contents
F 22 mm CH connection pipe --- 2 off. F 22 mm Gas supply connection pipe --- 1 off. F 15 mm DHW cold inlet connection pipe --- 1 off. F 15 mm DHW hot outlet connection pipe --- 1 off. F 1/2” connection nut --- 2 off. F 1/2” sealing washer --- 3 off. F 3/4” sealing washer --- 6 off. F 3/4” Gas supply isolating valve --- 1 off. F 3/4” CH circuit isolating valve --- 2 off. F 1/2” DHW cold inlet isolating valve --- 1 off.
Pack B contents
G Air intake pipe ø 100 mm (4”), flue pipe ø 60 mm (2” 3/8)
with terminal grille assembly
D
C
F
H Centring spring
I Turret--- air pipe gasket
J Flue pipe gasket
K Boiler--- turret gasket
L Flue turret
M Self tapping screws 4,8x13 --- 4 off
N Wall finishing gasket --- internal (plastic)
O Wall finishing gasket --- external (rubber)
O
N
M
G
L
H
I
K
Optional extras, if ordered, are available in separate boxes.
F Electronic programmer kits --- 24 hrs & 7 day F Extension duct kit pack D (ø 60/100) F Flue support kits ø 80, 100, 125 F Vertical outlet flue kit with elbow (ø 60/100) F 90° Elbow kit (ø 60/100) F 45° Elbow kit (ø 60/100) F Roof flue kit (ø 80/125) F Universal weather collar (for roof flue kit) F Flat roof weather collar (for roof flue kit) F Extension duct kit (ø 80/125) F 90° Elbow kit (ø 80/125) F 45° Elbow kit (ø 80/125) F Condense drain vertical (ø 80/125) F Twin pipe kit (ø 80) with air and flue terminals F Extension duct kit (ø 80) F 90° Elbow kit (ø 80) male---female F 45° Elbow kit (ø 80) male---female F Vertical condense drain (ø 80) F Horizontal condense drain (ø 80) F Condense trap F Stand--- off bracket F Natural gas to LPG conversion kit F LPG to natural gas conversion kit F Condensate pump kit
J
INSTALLATION
10 PACKAGING
To unpack the boiler refer to the instructions on carton end flap.
mini HE --- Installation & Servicing
15
Page 16
INSTALLATION
11 FITTING THE FLUE SYSTEM
The minimum and maximum equivalent length for co---axial pipes ø 60 ---100 and ø 80 ---125 mm are given in Table 6.
The minimum and maximum equivalent length for ø 80 mm twin pipe systems are given inTable 7.
For roof flue systems having a flue length greater than 3m and all twin pipe systems, a condensate drain kit must be fitted at the lowest point in the system. See the list of optional extras (frame 9) for available drain kits.
Refer to the assembly instructions contained within the chosen flue kit packaging for the correct assembly and
INSTALLATION
installation.
The horizontal sections of flue pipes must have a slope not less than 1.5 deg. (25 mm per metre) towards the boiler.
In the flue kit of pack B the flue pipe is angled within the air duct therefore the air duct must be horizontally installed.
In the case that one or more extensions need to be used they must be adequately supported so that there is no sag in the flue pipe and a minimum fall of 1.5 deg. (25 mm per metre) over the whole length towards the boiler is ensured.
Horizontal Concentric
Air duct
Rear Outlet Wall thickness + 125 mm
Rear outlet+Stand--- off Wall thickness + 160 mm
Side Outlet --- RH Wall thickness + Gap +62 mm
Side Outlet --- LH Wall thickness + Gap +208 mm
Twin pipe flue kits
For calculation of total flue length, the distance MUST be measured from the centreline of the flue duct/air duct connection to the end of the flue outlet grille/air inlet duct.
For each additional 45° M&F and 90° M&F flue bend used, the maximum permissible length of flue system must be reduced by 0,9m or 1,65m respectively.
Two restrictors with different sizes are supplied with the twin pipe kit and have to be installed between the boiler and the air intake adapter as indicated in the following picture.
The restrictor to be used and the lengths of allowable equivalent flue outlet / air inlet ducts are indicated in Table 7 and in the following graph.
The restrictor size is marked on its body.
Air intake adapte r
Table 6
Minimum Maximum
Co---axial 60---100 0.3 (11.8”) 2.7 (8’ 10”)
Co---axial 80---125 0.5 (19.7”) 8.5 (27’ 10”)
Co---axial Flue kits.
Horizontal. For calculation of total flue length, the distance MUST be measured from the centreline of the concentric elbow to the end of the terminal.
Vertical outlet For calculation of total flue length, the distance MUST be measured from the centreline of the outlet connector at the boiler top panel to the end of the terminal grille.
For each additional 45° and 90° flue bend used, the maximum permissible length of flue system must be reduced by 1 m or 1,5 m respectively.
Cutting lengths of flue and air ducts
Measure the wall thickness and, when using a side outlet, the gap between the inner wall and the boiler side casing. Use the following chart to calculate the cutting length of air duct.
Mark the air duct making reference on the groove.
Cut the flue duct at the same level of the air duct edge.
Cut this end
Groove
Restrictor
Gasket
Table 7
Equivalent pipe length
Restrictor
(air duct + flue duct)
Between 1 (39“) and 15 m (49’ 2”) ø 50 mm
More than 15 m (49’ 2”) up to 30 m (98’ 5”) ø 55 mm
Flue exhaust ”a”
32
30
28
26
24
22
20
18
16
14
12
10
8
6
Restrictor
4
50 mm
2
0
0 2 4 6 8 10 12 14 16 18 20 22 24 26 2 8 30 32
Restrictor
55 mm
Allowed values
Air intake ”b”
16
mini HE --- Installation & Servicing
Page 17
INSTALLATION
Cutting lengths of flue and air ducts
Measure the wall thickness and, when using a side outlet, the gap between the inner wall and the boiler side casing. Use the following chart to calculate the cutting lengths of both flue and air ducts.
Mark the air duct and flue duct making reference on the groove.
Groove
Groove
12 REAR FLUE ASSEMBLY
Legend
1 Wall finishing gasket --- external (rubber) 2 Self tapping screw 4,2x13 3 Flue turret 4 Boiler --- turret gasket 5 Flue pipe gasket 6 Turret--- air pipe gasket 7 Centring spring 8 Air/flue pipe with terminal grille assembly 9 Wall finishing gasket --- internal (plastic)
Twin Pipe
Air duct
Rear Outlet Wall thickness + 130 mm
Rear outlet+Stand--- off Wall thickness + 165 mm
Side Outlet --- RH Wall thickness + Gap + 187 mm
Side Outlet --- LH Wall thickness + Gap + 93 mm
Flue Duct
Rear Outlet Wall thickness + 130 mm
Rear outlet+Stand--- off Wall thickness + 165 mm
Side Outlet --- RH Wall thickness + Gap +67 mm
Side Outlet --- LH Wall thickness + Gap + 213 mm
1
2
9
8
7
6
5
3
4
INSTALLATION
13 WALL MOUNTING TEMPLATE
(rear flue)
IMPORTANT
Detailed installation steps are given directly on the wall mounting template
1 Tape the template into the selected position. 2 Ensure squareness by hanging a plumbine. 3 Mark onto the wall the following:
a. the wall mounting plate screw positions b. the position of the flue duct.
(Mark the centre of the hole as well as the circumference)
4 Remove the template from the wall
mini HE --- Installation & Servicing
b
a
17
Page 18
INSTALLATION
14 WALL MOUNTING TEMPLATE
(side flue)
IMPORTANT
Detailed installation steps are given directly on the wall mounting template
1 Tape the template into the selected position.
2 Ensure squareness by hanging a plumbine.
3 Mark onto the wall the following:
a. the wall mounting plate screw position b. Extended the centre line as shown.
Mark the flue ductcentre from the corner (see diagram
INSTALLATION
and template)
Note. mark the centre of the hole as well as the circumference. If extension duct kit pack D has to be used, the pipes must have the correct slope as detailed in frame 11.
4 Remove the template from the wall
15 DRILLING THE WALL
Rear flue shown
IMPORTANT
Ensure that, during the cutting operation, masonry falling outside the building does not cause damage or personal injury.
1 Cut the flue hole (preferably with a 5” core boring tool),
ensuring that the hole is square to the wall.
2 Drill the fixing holes with an 8mm (5/16”) masonry drill.
Fit suitable wall plugs (not provided).
Note. If the teminal is to be sited within 25 --- 40 mm of a corner or vertical pipe (refer to Table 4) then the hole MUST be accurately cut and the rubber weather seal trimmed.
5” diameter flue hole
Section through wall
Extended centre
Spirit level
16 FITTING THE WALL
MOUNTING PLATE
Refer to frame 18 for service connections.
Fit the wall mounting plate
Directly to the wall
F Offer up wall mounting plate. F Screw through the fixing holes using 3 off no. 14x2”
screws (not provided).
F Check alignment with spirit level. F Tighten screws.
Note: Check all of the hole positions before drilling.
18
mini HE --- Installation & Servicing
Page 19
INSTALLATION
17 MOUNTING THE BOILER
Lift the boiler onto the wall mounting plate locating the bar at the rear of the back panel assembly into the bracket.
As added protection, the boiler should be lifted with the lower polystyrene packaging in place.
Lower the boiler into position.
Remove the lower packaging. Remove the front and side panels (refer to frame 22) and strip off the protective coating. The panels may be placed to one side and re---fitted when the installation is complete.
Note. Before fitting the flue system, fili the condensate trap within the boiler by pouring a cupful of water into the flue outiet A. Take care to ensure that the water is only poured into the flue outiet, and does not spill into the boiler casing.
Fit the flue system referring to the instructions contained with the kit.
Make good the internal wall surface using the seal provided.
18 CONNECTIONS
Fit the service valves washers and tail pipes as shown.
A
INSTALLATION
Central Heating flow
Domestic hot water outlet
Connect to the tail pipes by proprietory fittings.
The pipework may be directed down or through the rear wall as required.
The pipework may be directed upwards by using the optional stand off bracket kit. See illustration for upward pipework routing
Gas inlet
Domestic cold water inlet
Central Heating return
19 SAFETY VALVE DRAIN
The discharge pipe should be positioned so that the discharge of water or steam cannot create a hazard to the occupants of the premises or damage to electrical components and wiring.
Pressure relief valve
mini HE --- Installation & Servicing
Discharge pipe
19
Page 20
INSTALLATION
20 CONDENSATE DRAIN
Refer also to the British Gas document: “Guidance Notes for the installation of Domestic Gas Condensing Boilers” (1989).
The condensate drain provided on the boiler must be connected to a drainage point, preferably within the building.
The boiler includes a trap that prevents combustion products entering the drain. However an additional trap with a seal of at least 75 mm and an air break between the traps is required if the condensate drain pipe is connected to sanitary pipework.
INSTALLATION
The length of the condensate pipe should be kept at minimum and must be arranged so that obstruction (e.g.
Condensate drain
Additional trap
21 ELECTRICAL CONNECTIONS
Warning. This appliance MUST be efficiently earthed
A mains supply of 230 V ~ 50 Hz is required.
Mains wiring should be 3 core PVC insulated flexible cord NOT LESS than 0.75 mm2(24 x 0.2mm) and to BS. 6500, Table 16. (0.5mm2flex is not acceptable --- for mechanical, not electrical reasons.)
Mains wiring external to the boiler MUST be in accordance with the current I.E.E. (BS7671) Wiring Regulations and any local regulations.
through freezing) of external drainage pipework does not give rise to spillage within the dwelling.
If a part of the drainpipe runs externally this part should be kept as short as possible and protected to reduce the risk of freezing.
IMPORTANT
If excessive external pipework cannot be avoided an additional condensate removal pump (available as an option) and insulation are recommended to prevent possible freezing.
The drain outlet on the boiler is a 25 mm o.d. plastic pipe. This size must not be reduced below 21.5mm o.d. (standard overflow pipe) in any part of its length.
All pipework and fittings in the condensate drain system must be made of plastic. No other materials may be used.
To avoid condensate being trapped:
--- the drainpipe should be run with a fall of at least 2.5° (45 mm/m) away from the boiler;
--- the number of bends and joints should be kept at minimum;
--- the drainpipe should be adequately fixed to pevent pipe sagging.
For Ireland reference should be made to the current ETCI rules for electrical installations.
The supply connection is intended to be made via a double pole switch having a 3 mm (1/8”) contact separation in both poles, serving only the boiler and system controls. A 3 pin UNSWITCHED socket may, alternatively, be used.
The fuse rating should be 3 A.
For external controls wiring see frame 25. Note: the switch contacts of any external programmer, room or frost thermostat must be volt free. Connecting a switched live feed to external controls terminal block may be dangerous and will result in serious damage to the boiler.
20
mini HE --- Installation & Servicing
Page 21
INSTALLATION
Mains
22 ELECTRICAL CONNECTIONS
Incoming mains wiring detail
To gain access to the power supply and external controls terminal blocks:
1 Remove the screws A and the front panel of the case.
A
2 Remove the screws B.
3 Loosen the screws C.
4 Remove the side panels or move the lower part of the side
panels and pull the control panel.
When completely pulled out, the panel can rotate 45° downwards to facilitate the operations on the internal parts.
5 Loosen the screws D and remove the service panel.
INSTALLATION
D
Volt free contacts Thermostat link Remove when wiring external thermostats.
B
Refer to frame 25
3
12
L N
Power supply terminal block
External controls terminal block
B
C
C
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.
mini HE --- Installation & Servicing
21
Page 22
INSTALLATION
23 PICTORIAL WIRING
mini HE C24, mini HE C28
Wiring diagram for boiler equiped with full sequence ignition device type: Bertelli & Partners FM30
External controls Electric supply
123
terminal blockterminal block
Flue
thermostat
bu
bu
bn
gnye
Safety
thermostat
bu
bn
bnbn
Fan Air pressure
switch
M
~
vt
og
gnye
NC
electrodes
bn
bu
NO
bk
COM
INSTALLATION
Ignition
Flame detection
electrode
rd
gybnbu
bu gy
rd
Electronic
control p.c.b.
bn = brown bu = blue bk = black wh = white rd = red gy = grey gn = green ye = yellow vt = violet og = orange gnye = green/yellow
t
bk bk
probe NTC
rd
bk
bk
bu
rd
bk
gy
bk
rd
rd
bk
bu
wh
rd
wh rd
bu
DHW flow
switch flow switch
Primary circuitDHW temperature
gnye
gnye
gnye
bk bu bn
bu
bn
gnye
P.C.B. #1
bk
bu
CH temperature
bu
gnye
gnye
bn bu bk bn
bu
P.C.B. #2
t
probe NTC
bk
bu
bn
bu bn bk bu
bn
bkbnbu
312
M
~
bn
bu
bu bn bk bu
bn
Full sequence
ignition device
bn
bu
gnye
M
~
Condensate
gnye
gnye gnye
bk
rd
bk gyrd
bk
gnye
bu
gnye
bn
trap
gnye
Electronic control p.c.b. Pin position ref. numbering
4
3 2 1
22
21
22
Three way
diverter valve
Pump
Full sequence ignition device
P.C.B. #1 P.C.B. #2
313029282726252423
1617181920
Pin position ref. numbering
116 115 114
5
113 6 7
112 8
111
110 9
109
108
10
107
11
106
12 13 14
105
104
15
103
102
101
117
118
119
120 121
122
Modulating
gas valve
rd bk wh
gn
Time switch
(optional)
mini HE --- Installation & Servicing
Page 23
INSTALLATION
Wiring diagram for boiler equiped with full sequence ignition device type: Honeywell FPLD
External controls Electric supply
123
rd
gybnbu
Electronic
control p.c.b.
bn = brown bu = blue bk = black wh = white rd = red gy = grey gn = green ye = yellow vt = violet og = orange gnye = green/yellow
terminal blockterminal block
Flue
thermostat
bu
bu
bn
gnye
bu gy
rd
bk
gy
bk
Fan Air pressure
Safety
thermostat
bu
bn
bnbn
bu
~
M
gnye
vt
og
switch
NC
bn
bu
NO
bk
COM
Ignition
electrodes
Flame detection
electrode
INSTALLATION
gnye
gnye
bk bu bn
bn
P.C.B. #1
gnye
bn bu bk bn
bu
P.C.B. #2
bk
bu
bn
bu bn bk bu
bn
bn
bu
bu bn bk bu
bn
Full sequence
ignition device
Condensate
gnye
gnye gnye
rd
bk
trap
gnye
gnye
rd
bk
bu
rd
bk
bu
rd
rd
bk
bu
wh
gnye
t
bk bk
probe NTC
Electronic control p.c.b. Pin position ref. numbering
4
3 2 1
22
DHW flow
21
rd
wh rd
bu
switch flow switch
Primary circuitDHW temperature
P.C.B. #1 P.C.B. #2
5 6 7
313029282726252423
1617181920
8
9 10 11
12 13 14
15
bk
t
bu
CH temperature
probe NTC
Three way
diverter valve
Full sequence ignition device Pin position ref. numbering
116 115 114
113
112 111 110 109 108 107
106
105 104 103 102
101
~
M
bkbnbu
312
bn
bu
gnye
M
~
Pump
117
118
119
120 121
122
bk gyrd
bk
gnye
bu
gnye
bn
Modulating
gas valve
rd bk wh
gn
Time switch
(optional)
gnye
mini HE --- Installation & Servicing
23
Page 24
24 FUNCTIONAL FLOW DIAGRAM
mini HE C24, mini HE C28,
INSTALLATION
L
Pump
CH temp. probe
DHW temp. probe
Three way div. valve
Gas Valve (modulation coil)
bn
4
bu
8
bn
9
bk
28
bu
29
bk
rd
bk
bu
bn
gy
bk
Main
19
control pcb
20
5
6
7
22
23 16 17 30 31
17
rd
P.C.B. #1 P.C.B. #2
wh
INSTALLATION
Ignition electrodes
15
bu
14
bn
13
bk
12
bu
11
bn
105
bu
104
bn
103
bk
102
bu
101
bn
117
118
119
107
106
bu
bn
Ignition pcb
108
bk
109
bn
110
rd rd
27
26
bk bk
3
bu
rd bkbu
122
120
bk bu
113114 115
bn
bu
111
bu
112
bn
Gas Valve (on--- off operators)
Detection electrode
Air pressure switch
Fan
Flue thermostat
bn
bn
Safety thermostat
Condensate trap
DHW flow switch
CH flow switch
N
24
mini HE --- Installation & Servicing
Page 25
INSTALLATION
25 EXTERNAL ELECTRICAL CONTROLS
Wiring external to the boiler MUST be in accordance with the current I.E.E. (BS.7671) Wiring Regulations.
For Ireland reference should be made to the current ETCI rules for electrical installations.
The fuse rating should be 3A.
Route the electrical supply flexible cord and the external control flexible cord as illustrated. Lock the flexible cords in place with the clamps provided.
230V supply
ELECTRICAL CONNECTIONS FOR A COMBI BOILER
Optional Programmer Kits
Optional digital programmer kits are available with their relevant instructions.
Both 24hr and 7day kits are available.
Note: the switch contacts of any external programmer, room or frost thermostat must be volt free. Connecting a switched live feed to external controls terminal block may be dangerous and will result in serious damage to the boiler.
Room Thermostat
This should be wired as shown in diagrams A.
Frost protection
Central heating systems fitted wholly inside the house do not normally require frost protection as the house acts as a ‘storage heater’ and can normally be left at least 24 hours without frost damage.
However, if parts of the pipework run outside the house or if the boiler will be left off for more than a day or so then a frost thermostat should be wired into the system. To maintain frost protection with the programmer selector
switches set to OFF, all the controls MUST be left in the running position.
The frost thermostat should be sited in a cold place but where it can sense heat from the system.
Wiring should be as shown, with minimal disturbance to other wiring.
External Programmers
On the combi boilers, this should be of the single channel type (as this boiler does not incorporate a pre--- heat facility for the instantaneous hot water service).
Programmers with room thermostat --- see diagram B.
Note. lf the boiler is installed in a garage it may be necessary to fit a pipe thermostat, preferably on the return pipework.
Earths are not shown for clarity but must never be omitted.
A
Optional frost’stat
Room thermostat
L N
T
T
Power supply terminal block
12
External controls
3
terminal block
B
External programmer
Optional frost’stat
T
N.B. These diagrams are schematic only and do not show external terminal strips etc.
Room thermostat
T
3
L N
Power supply terminal block
12
External controls terminal block
INSTALLATION
mini HE --- Installation & Servicing
25
Page 26
26 INITIAL LIGHTING
INSTALLATION
A B C D E F
INSTALLATION
Legend
A Appiance On lamp
B Domestic hot water temperature control
C Main switch and radiator temperature control
D Boiler reset button
E Lock--- out signal lamp
F Programmer (optional)
G System pressure and temperature gauge
G
Central Heating flow
Domestic hot water outlet
Gas inlet
Domestic cold water inlet
Central Heating return
IMPORTANT Before lighting the boiler you should note especially that:
1 Check that all the drain cocks are closed and any valves
in the flow and return are open.
2 Check that the system has been filled and pressurised
and that the boiler is not air locked.
3 Remove boiler front panel.
4 Ensure the dust cap on the automatic air vent is open at
least one full turn and leave this permanently open
5 Ensure that the pump is free to rotate
i Remove the vent plug ii Using a screwdriver, rotate the shaft several times iii Replace the vent plug
Note. Some slight water leakage will occur
6 Remove the screw in the burner pressure test point
indicated on the following picture and connect a gas pressure gauge via a flexible tube. Be sure to select the correct pressure test point. Refer to Tables for pressures.
7 Check that the gas service cock is ON. 8 Switch the electricity supply ON and check that all
external controls are calling for heat.
9 Set the main switch C to ’ON’. Following a pre --- purge
period the gas control solenoid valve should open and the spark commence, continuing until the burner is established.
10 Check that the burner lights smoothly. If this does not
occur within 20 seconds, turn the main switch to ’O’ position, wait for 5 seconds then try again by pressing the reset button ’D’. If the burner still does not light, refer to the ’Fault Finding’ section.
11 Test for gas soundness around ALL boiler gas
components, using leak detection fluid.
12 Operate the boiler for 10 minutes to stabilise the burner
temperature.
13 Check that the burner pressures are correct. The boiler is
factory pre--- set and should not need adjustment.
However if adjustment is required refer to frame 27. 14 Set the boiler main switch to ’O’. 15 Remove the pressure gauge and tube. Replace the
sealing screw in the pressure test point. Ensure a gas
tight seal is made. 16 Refit the boiler front panel using the screws previously
removed. 17 Switch the boiler on again.
26
mini HE --- Installation & Servicing
Page 27
27 TO ADJUST PRESSURES
Nomenclature of the parts on the gas valve
A Modulation operator’s electric connectors
B Minimum gas pressure adjustment
C Maximum gas pressure adjustment
D Gas valve inlet pressure test point
E Burner pressure test point
E
D
C
INSTALLATION
A
B
(burner pressure).
By rotating clockwise the pressure increases. 10 Turn the boiler off and re---connect the wire to the
modulating operator. 11 Start the boiler and check again the maximum gas
pressure setting. 12 Turn the boiler off and disconnect the gauge and close the
gas valve outlet pressure test point E
Important: after the gas pressure checks and any adjustment operations, all of the test points must be sealed.
Ignition rate adjustment
1 Turn on the boiler. 2 Check that the boiler lights up uniformly and adjust the
ignition gas pressure, if necessary.
To adjust the ignition gas pressure:
3 Open the gas valve outlet pressure test point E and
connect the gauge. 4 Loosen the screws F and remove the service panel
F
INSTALLATION
1 Remove the front panel of the case. 2 Open the gas valve inlet pressure test point D at the valve
input, connect a suitable pressure gauge and check the
gas pressure of the supply network. 3 Remove the gauge and close the pressure test point D. 4 Open the burner pressure test point E and connect the
gauge. 5 Remove the protection cap from the mechanical pressure
adjustment components (B and C) 6 Start the boiler at its maximum power.
Operate the boiler in DHW mode or ensure that the boiler
is not range rated if the test is carried out in CH mode.
Maximum valve setting
7 If necessary, rotate the maximum gas pressure
adjustment C using a spanner until you obtain the
required pressure as indicated on Table 1 at page 4
(burner pressure).
By rotating clockwise the pressure increases.
Minimum valve setting
8 Disconnect one of the two connectors A. 9 If necessary, rotate the minimum gas pressure adjustment
B using a pozidrive screwdriver until you obtain the
required pressure as indicated on Table 1 at page 4
Service panel
5 set dip --- switch ”3” to the OFF position and adjust
potentiometer marked “ACC” with a screwdriver until correct ignition gas pressure is obtained.
+
ACC
ON
1
2
3
4
OFF
Suggested ignition pressures:
Natural gas G20 --- 6 (2,4) mbar (in w.g.) Propane G31 --- 13 (5,3) mbar (in w.g.)
mini HE --- Installation & Servicing
27
Page 28
INSTALLATION
28 ANTI CYCLING SETTING
If the dipswitch number 4 on the main P.C.B. is set to the ’ON’ position it will activate the re--- ignition delay period of approximately 3 minutes. When dipswitch number 4 is set to the ’OFF’ position there will be approximately 30 seconds re---ignition delay period.
29 COMMISSIONING AND TESTING
INSTALLATION
The benchmark Logbook or equivalent self certification should be completed and signed to demonstrate compliance with Building Regulations.
A. Electrical Installation
Checks to ensure electrical safety should be carried out by a competent person.
ALWAYS carry out the preliminary electrical system checks, i.e. earth continuity, polarity, resistance to earth and short circuit, using a suitable test meter.
3 minutes 30 sec.
ON
4
1 2 3
OFF
B. Gas Installation
1 The whole of the gas installation, including the meter,
should be inspected and tested for soundness and purged in accordance with the recommendations of BS.
6891. In IE refer to I.S. 813:2002.
2 Purge air from the gas installation by loosening the gas
cock union and purge until gas odour is detected.
3 Retighten the union and test for gas soundness.
WARNING. Whilst effecting the required gas soundness test and purging air from the gas installation, open all windows and doors, extinguish naked lights and DO NOT SMOKE.
ON
123
OFF
4
30 GENERAL CHECKS
Make the following checks for correct operation:
1 Hot water.
a. Fully open all DHW taps in turn and ensure that water flows freely from them.
b. Close all taps except the furthest one from the boiler and check that the boiler is firing at maximum rate.
c. Ensure that DHW temperature of approximately 35 ° C rise is obtained at the tap. This corresponds to a flow rate of about
litres/min (gpm)
10.1 (2.2) mini HE C24
11.7 (2.6) mini HE C28
d. Turn off the DHW tap.
2 Central heating (all models)
Operate each control separately and check that the main burner or circulating pump, as the case may be, responds.
3 Gas rate --- G20
Check the boiler gas rate when the boiler is at full output.
The gas rate checked at the gas meter, with no other appliance in use will normally be:
litres/min (ft3/min)
44.2 (1.56) mini HE C24
51.2 (1.81) mini HE C28
If this check is not possible, ensure that the burner pressure is:
models
models
10.8 (4.3) mbar (in. w.g.) for the model mini HE C24 and
10.0 (4.0) mbar (in. w.g.) for the model mini HE C28.
mbar (in. w.g.)
10.8 (4.3) mini HE C24
10.0 (4.0) mini HE C28
4 Water circulation system
Note. Fernox Superfloc flushing solution should be used during the flushing procedure.
models
a. With the system HOT examine all water connections for
soundness.
b. With the system still HOT, turn off the gas, water and electricity supplies to the boiler and drain down, to complete the flushing process.
c. Refill the system, adding inhibitor (see ’Water Treatment’), if required.
Vent as necessary to clear all air and, again, check for water soundness. After venting, repressurise as required.
d. Balance the system. It is suggested that, initially, all radiator handwheel valves (or TRVs if fitted) be set fully open, that all lockshield valves be set a half--- turn open.
Make minor adjustments to each radiator to achieve the same differential on all.
5 Flue system
Check the integrity of the flue outlet and air inlet system to the boiler ensuring no leaks are evident from piping joints or flue/air sampling points.
Finally, set the system controls to the users requirements.
If an optional programmer kit is fitted refer to the instructions supplied.
28
mini HE --- Installation & Servicing
Page 29
INSTALLATION
31 GAS CONVERSION
1 Disconnect the electrical supply. 2 Replace the burner injectors as explained in frame 43. 3 Re---assemble the burner, the front panel of the
combustion chamber and the lid of the sealed chamber. 4 Remove the service panel (frame 27 step 4). 5 Set correctly the dip--- switch ”2” to the correct position in
accordance with the following table and drawing.
Gas supply
Natural gas On
Propane Off
Position of dip--- switch 2
Natural gas L.P.G.
ON
1 2 3
OFF
4
ON
123
OFF
4
32 HANDING OVER
After completing the installation and commissioning of the system, the installer should hand over to the householder by the following actions:
1 Hand the User’s Instructions to the householder and
explain his or her responsibilities under the Gas Safety
(Installation and Use) Regulations 1994 and amendments
1996 or rules in force. 2 Draw attention to the Lighting Instruction label affixed to
the inside of the lower front door. 3 Explain and demonstrate the lighting and shutting down
procedures. 4 The operation of the boiler and the use and adjustment of
ALL system controls should be fully explained to the
householder, to ensure the greatest possible fuel
economy consistent with household requirements of both
heating and hot water consumption. 5 Advise the user of the precautions necessary to prevent
damage to the system and to the building, in the event of
the system remaining inoperative during frosty conditions.
6 Adjust the burner pressures according to the indications
given in frame 27.
7 Stick the self--- adhesive label (included with the
conversion kit, indicating the type of gas, and the gas pressures to which the appliance has been set) over the existing label on the bottom of the control panel.
8 Replace the service panel and the front and side panels of
the case.
9 Check the correct operation of the boiler.
INSTALLATION
6 If a programmer is fitted, draw attention to the
Programmer Instructions and hand them to the householder.
7 After installation and commissioning please complete the
Commissioning Checklist before handover to the customer. For IE, it is necessary to complete a “Declaration of Conformity” to indicate compliance to I.S. 813:2002.
8 Stress the importance of regular servicing by a CORGI
registered installer and that a comprehensive service should be carried out AT LEAST ONCE A YEAR. In IE, servicing work must be carried out by a competent person.
Emphasise to the user that the boiler may stop working if the system pressure is lowered by draining radiators to decorate behind them. In particular, explain to the user how the domestic hot water temperature varies with flow rate. This is especially important when water is drawn off while the boiler is already running for central heating.
mini HE --- Installation & Servicing
29
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SERVICING
33 SERVICING SCHEDULE
To ensure the continued safe and efficient operation of the appliance it is recommended that it is checked at regular intervals and serviced as necessary.
The frequency of servicing will depend upon the installation condition and usage but should be carried out at least annually.
It is the law that any service work must be carried out by a registered CORGI installer. In IE, servicing work must be carried out by a competent person.
SERVICING
1 Turn the heating controls to maximum so that the boiler
lights and remains running. Check that no other gas appliances in the house are in use or likely to be used.
2 When the boiler has settled down check the gas rate at
the meter (if the meter is of the pointer type you should time only complete revolutions of the pointer). Check the gas rate against the figures given in Table 2 for CH operation.
3 For a combination boiler, fully open a hot water tap. When
the boiler has settled down check the gas rate, as in step 2, checking the measured rate against the figures given in Table 3 for HW operation.
4 Run the boiler and check the percentage of CO and CO2
in the flue gasses at the sampling point indicated in the following drawing.
Air intake Sampling points
Note. If your meter reads CO in parts per million the figure must be divided by 10,000 to convert it to a percentage.
5 If the ratio of CO/CO2is less than ,004 and the gas rates
measured in steps 3 and 4 are close to nominal then no further action need be taken. If not, proceed to step 6.
6 Clean the main burner. 7 Clean the heat exchanger. 8 Check the injectors for blockage or damage. 9 Check that the flue terminal is unobstructed.
The servicing procedures are covered more fully in Frames 34 to 36 and MUST be carried out in sequence.
WARNING.
ALWAYS turn off the gas supply at the gas service cock, and switch off and disconnect the electricity supply to the appliance before servicing.
Switching the boiler on/off switch ‘off’ does not fully isolate the boiler.
ALWAYS test for gas soundness and carry out functional checks on reassembly.
IMPORTANT. When work is complete the boiler inner front sealing panel MUST be correctly refitted, making a good seal.
DO NOT OPERATE THE BOILER IF THE SEALlNG PANEL IS NOT FITTED.
Complete the service section in the Benchmark Commissioning Checklist.
Exhaust gas Sampling points
30
mini HE --- Installation & Servicing
Page 31
SERVICING
34 REMOVAL OF OUTER AND INNER
CASING
1 Turn off the gas supply at the gas service cock and
disconnect the electricity supply.
2 Remove the screws A and lift off the boiler front panel.
A
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.
C
SERVICING
C
B
B
mini HE --- Installation & Servicing
31
Page 32
SERVICING
35 BURNER REMOVAL AND CLEANING
1 Disconnect the electrical supply. 2 Remove outer and inner casing (refer to frame 34). 3 Undo the screws A and remove the fan holder bracket B
and the combustion chamber panel C.
4 Remove the screws D and the plate E.
SERVICING
B
A
A
6 Undo the four screws F placed at the right and left sides of
the burner and extract it.
F
7 Brush off any deposits that may have collected on the
burner, ensuring that the flame ports are unobstructed. Note: brushes with metallic bristles MUST NOT be used.
8 Inspect the spark and detection electrodes. Ensure they
are clean and in good condition; replace if necessary.
9 Check the spark electrodes gap is correct.
4 mm (5/32”)
C
D
5 Disconnect the electrodes leads.
36 BURNER PRESSURE CHECK
After any servicing, reference should be made to:
--- Table 2 and Table 3 (or the data plate) which quote details
of the burner pressures.
37 CLEANING THE HEAT EXCHANGER
1 Open the combustion chamber as explained in steps 1 to
3 of frame 35.
E
10 mm (3/8”)
Ignition
Female
10 Check that the spark and detection electrodes leads are in
good condition and renew as necessary.
If the burner pressures are incorrect ensure the inlet pressure, with the appliance running, is correct (refer Table 1).
If the burner pressures require adjustment refer to frame 27 “To adjust pressures”.
If the appliance still does not operate correctly refer to the appropriate fault finding chart.
2 Place a plastic sheet or similar beneath the heat
exchanger and remove all visible loose deposits from the heat exchanger fins, using a suitable brush.
Detection
Burner blade
Male
38 RE ---ASSEMBLY
Re --- assemble the boiler in the following order: 3 Refit the burner. 4 Reconnect the electrodes to the ignition pcb. See frame
35 for correct connectors.
5 Refit the combustion chamber panel and the fan holder
bracket.
32
6 Refit the inner case cover.
IMPORTANT. Ensure the boiler sealing panel is correctly fitted and that a good seal is made.
7 Refit the boiler side and front panels.
8 Turn on the gas supply at the gas service cock.
9 Reconnect the electrical supply.
mini HE --- Installation & Servicing
Page 33
SERVICING
39 FAN AND VENTURI REMOVAL AND
CLEANING
1 Disconnect the electrical supply.
2 Remove outer and inner casing.
3 Disconnect the connectors A and the earth connection B.
4 Disconnect the pipe which connects the venturi device to
the air pressure switch.
5 Unscrew the screw C and remove the fan holder bracket
D.
A
C
D
B
7 Check that the impeller runs freely. Clean with a soft brush
or renew as necessary. Refer to frame 51 for replacement.
Note: Always take care when handling the fan, in order to preserve the balance of the impeller.
8 Check the venturi E for cleaness.
E
SERVICING
9 Re---assemble in reverse order.
To correctly connect the venturi device to the air pressure switch, refer to the following illustration.
--- +
6 Remove the fan by sliding it towards left (see the arrow).
mini HE --- Installation & Servicing
33
Page 34
SERVICING
REPLACEMENT OF COMPONENTS
40 GENERAL
When replacing any component:
1 Isolate the electricity supply at the switched spur.
N.B. Turning the boiler “ON/OFF” switch does not isolate the live supply to the boiler.
2 Turn off the gas supply.
SERVICING
IMPORTANT. When work is complete the inner case cover must be correctly fitted, ensuring that a good seal is made.
41 SPARK AND DETECTION
ELECTRODE REPLACEMENT
1 Disconnect the electrical supply. 2 Remove outer and inner casing (refer to frame 34). 3 Open the combustion chamber and disconnect the
electrodes leads. 4 Remove the burner. Refer to frame 35. 5 Undo the screws that hold the electrodes and remove. 6 Fit new electrodes as necessary following the sequence
illustrated.
Ignition 1
Ignition 2
st
nd
Detection 3
rd
THE BOILER MUST NOT BE OPERATED IF THE INNER CASE COVER IS NOT FITTED.
If the CH and/or the DHW circuits have been emptied:
3 Open the hydraulic circuit cocks, refill / re--- pressurise
pipeworks and vent the system.
4 Test fire the boiler
5 Disconnect the filling loop.
7 Check the spark gap.
4 mm (5/32”)
10 mm (3/8”)
Ignition
Female
8 Re---assemble in reverse order. 9 Check the ignition and operation of the burner.
Detection
Burner blade
Male
42 BURNER REPLACEMENT
1 Remove the burner as explained in frame 35 2 Remove the spark and detection electrodes.
Refer to frame 41.
43 BURNER INJECTORS
REPLACEMENT
1 Remove the burner. Refer to frame 35.
2 Unscrew the injectors from the gas manifold.
3 Check that the new injectors are of the correct size and fit
it using new gaskets.
4 Re---assemble in reverse order.
5 Check the operation of the boiler.
3 Fit the electrodes on the new burner and check the spark
gap.
4 Re---assemble in reverse order.
5 Check the operation of the boiler.
Injectors
Burner
Gas manifold
mini HE --- Installation & Servicing34
Page 35
SERVICING
44 OVERHEAT THERMOSTAT
REPLACEMENT
1 Remove outer and inner casing (refer to frame 34). 2 Remove the screws A and the plate B.
B
A
45 FLUE THERMOSTAT REPLACEMENT
1 Remove outer and inner casing (refer to frame 34). 2 Disconnect the wires from the flue thermostat. 3 Unscrew and remove the thermostat probe A from the
recuperator. 4 Remove the protective cap B and unscrew the screws C
which hold the flue thermostat to the frame. 5 Remove the flue thermostat. 6 Assemble the flue thermostat carrying out the removal
operations in reverse sequence.
3 Disconnect the wiring C .
4 Remove the spring D which holds the overheat thermostat
on the pipe of the primary heat exchanger and remove it.
C
D
5 Re---assemble in reverse order.
6 Apply an adequate quantity of heat conducting
compound between the pipe and the thermostat.
A C
B
SERVICING
46 THERMISTOR REPLACEMENT
1 Disconnect the electrical supply. 2 Remove the front and right hand side casing panels (refer
to frame 34).
Removal of CH thermistor
3 To remove the CH thermistor close off the isolating cocks
of the CH circuit at the bottom of the boiler. 4 Release system pressure by opening the main circuit
drainage cock.
Do not release CH pressure using the pressure relief
valve. It may cause debris within the system to foul
the valve.
Removal of DHW thermistor
3 To remove the DHW thermistor close off the isolating cock
of the DHW circuit at the bottom of the boiler. 4 Empty the DHW circuit. 5 Disconnect the leads from the thermistors to be replaced
and unscrew it .
6 Screw in the new sensor, using a new gasket, reconnect
and re---assemble in reverse order.
CH thermistor DHW thermistor
Drainage cock
mini HE --- Installation & Servicing 35
Page 36
SERVICING
47 GAS VALVE ON ---OFF OPERATOR
COILS REPLACEMENT
Check
1 Disconnect the electrical supply. 2 Remove the front casing panel. 3 Disconnect the connector A and check the electrical
resistance of the coils referring to the following diagram
Upper on---off operator
SERVICING
approx. 6 400 W*
Lower on---off operator approx. 920 W*
* at ambient temperature.
4 If the resistance of either of the coils is different from the
value stated by ±10% or greater, replace the unit as
described below.
48 GAS VALVE REPLACEMENT
1 Turn off the gas supply at the gas service cock and
disconnect the electricity supply.
2 Remove the front casing panel (refer to frame 34).
Replacement
5 Remove the screw B, withdraw the coils unit C.
6 Replace it and re--- assemble in reverse order.
A
C D
B
C
3 Disconnect the connectors A and B.
4 Disconnect the earth wiring from the gas valve.
5 Unscrew the connectors C and remove the pipe D
6 Unscrew the inlet connector.
7 Unscrew the screws E and remove the valve.
8 Fit the new gas valve in reverse order ensuring new
gaskets are fitted and check for gas soundness.
9 Check the operation of the boiler.
49 WATER TEMPERATURE ---PRESSURE
GAUGE REPLACEMENT
1 Disconnect the electrical supply.
2 Remove the front and right hand side casing panels (refer
to frame 34).
3 Release system pressure by opening the main circuit
drainage cock A
Do not release CH pressure using the pressure relief
valve. It may cause debris within the system to foul
the valve.
4 Remove the fork B and the probe holder spring C.
5 Pull out the control panel (see frame 22).
6 Squeeze the tabs D to release the temperature---pressure
gauge E and remove it.
7 Re---assemble in reverse order.
A
B
E
E
D
C B
A
mini HE --- Installation & Servicing36
Page 37
SERVICING
50 EXPANSION VESSEL REPLACEMENT
If the CH expansion vessel is faulty, there are 2 options:
A If it has a punctured diaphragm, but is otherwise leak free,
than it can be left in place and a new vessel added to the
return side of the system, external to the boiler, provided it
is of adequate capacity and pre--- charge pressure.
B If there is at least 400 mm (16”) clearance above the
boiler, the expansion vessel can be changed without
removing the boiler (rear exit flues will have to be
disturbed).
For option B, proceed as follows:
1 Disconnect the electrical supply.
2 Gain access to the controls area by removing the boiler
front panel (refer to frame 34).
3 Close off the isolating cocks of the CH circuit at the
bottom of the boiler.
4 Release system pressure by opening the main circuit
drainage cock.
Do not release CH pressure using the pressure relief
51 FAN REPLACEMENT
1 Disconnect the electrical supply. 2 Remove outer and inner casing. 3 Disconnect the connectors A and the earth connection B. 4 Disconnect the pipe which connects the venturi device to
the air pressure switch. 5 Unscrew the screw C and remove the fan holder bracket
D.
A
B
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.
AB
SERVICING
6 Re---assemble in reverse order.
6 Remove the fan by sliding it towards left (see the arrow). 7 Re---assemble in reverse order.
Note: Always take care when handling the fan, in order to preserve the balance of the impeller.
To correctly connect the venturi device to the air pressure switch, refer to the following illustration.
--- +
C
D
52 VENTURI REPLACEMENT
1 Remove the fan (see frame 51). 2 Remove and replace the venturi device A by unscrewing
the screw B. 3 Re---assemble in reverse order.
A
B
mini HE --- Installation & Servicing 37
Page 38
53 AIR PRESSURE SWITCH
REPLACEMENT
Two different types of air pressure switch may be used in the boiler. Refer tho the following drawings in accordance with the type of air pressure switch used.
1 Disconnect the electrical supply. 2 Remove outer and inner casing as explained in frame 34. 3 Disconnect the pressure sensing pipe from the air
pressure switch. 4 Disconnect the electrical harness from the air pressure
switch.
SERVICING
5 Undo the two screws which hold the air pressure switch to
the chassis and remove it. 6 Replace the switch. 7 Re---assemble in reverse order.
To correctly connect the venturi device to the air pressure switch, refer to the illustration of frame 51 and to the following illustrations in accordance with the type of pressure switch used.
SERVICING
”H” connection
(not used)
”L” connection
COM
N.O.
”L” connection
N.C.
”H” connection
(not used)
54 PUMP REPLACEMENT COMPLETE
1 Disconnect the electrical supply.
2 Remove the front and right hand side casing panels (refer
to frame 34).
3 Release system pressure by opening the main circuit
drainage cock.
Do not release CH pressure using the pressure relief
valve. It may cause debris within the system to foul
the valve.
4 Disconnect the connector A.
5 Loosen the connector B.
6 Remove the fork C and the pipe D.
C DAB
7 Remove the fork E and the connection of the capillary
pipe of the pressure gauge.
8 Remove the locking plate F.
9 Completely loosen the connection G.
10 Unscrew the two screws H that hold the pump on the
frame
11 Remove the pump towards the front of the boiler
E
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.
H
IGF
mini HE --- Installation & Servicing38
Page 39
SERVICING
55 MAIN CONTROL PCB
REPLACEMENT
1 Disconnect the electrical supply.
2 Gain access to the controls area by removing the boiler
front panel and pulling the control panel (refer to frame
22).
3 Remove the screws A and remove the service panel
4 To gain access to the main control p.c.b. and the ignition
p.c.b. remove the screws B and remove the control panel
lid.
B
A
B
Control panel lid
Service panel
5 Remove all the wiring connected to the main control p.c.b.
To disconnect the connectors indicated, delicately flex the
hook present on one side of each socket.
7 Unscrew the four screws that hold the main control p.c.b.
on to the control panel.
8 Remove it by lifting its rear edge and freeing it from any of
the wiring.
9 Re---assemble in reverse order.
Setting jumpers
Two setting jumpers C are fitted on the main control p.c.b.
Refer to the following illustration for the position of the jumpers when the main control p.c.b. is fitted.
The numbers refer to the marking printed on the circuit board.
1 2 3 4 5 6 7 8 9
Important
When re---assembling the electronic control p.c.b.:
10 Fit the p.c.b. into the control panel by first inserting the
front lower edge under the control knob shafts. Lower the rear edge and ensure that no wiring is trapped beneath.
11 Insert the spindles in the control panel knobs until the
notch D reaches the potentiometer edge. It is not necessary to force them in the knob.
12 While tightening the screws that fix the main control p.c.b.
on the control panel, keep the p.c.b. towards the control panel fascia making sure of the contact between the boiler reset button E and the tab F. Replace the wiring connections ensuring correct engagement in the sockets
SERVICING
6 Remove the spindles of the CH and DHW temperature
adjustment knobs by delicately pulling them with pliers in
the direction shown by the arrow.
C
D E F
Attention
After installing the main control p.c.b.:
13 Make sure the CH (
adjustment knobs can move freely for the complete range. If not, remove the spindle again as described at step NO TAG, turn the knob half a turn and re---insert the spindle.
14 Operate the boiler and close the gas inlet cock so that the
boiler goes into the safety lock---out state. Verify the correct operation of the boiler reset button by pressing and releasing it.
15 Open the gas inlet cock and check the boiler operates
correctly.
) and DHW ( ) temperature
mini HE --- Installation & Servicing 39
Page 40
SERVICING
56 IGNITION PCB REPLACEMENT
1 Gain access to the parts located inside the control panel
as explained in the the frame 55. 2 Remove all the wiring connected to the ignition p.c.b.
To disconnect the connectors indicated, delicately flex the
hook present on one side of each socket. 3 Unscrew the two screws A that hold the ignition p.c.b. on
the panel and remove the component. 4 Re---assemble in reverse order. 5 Check the boiler operates correctly.
SERVICING
57 CH FLOW SWITCH REPLACEMENT
1 Disconnect the electrical supply.
2 Remove the front casing panel.
3 Remove the fork A.
4 Open the box B and disconnect the switch.
A
A
5 Re---assemble in reverse order.
Refer to the following illustration for the correct wiring connectors on the switch
C
N.O.
A
B
58 CH FLOW SWITCH MEMBRANE
REPLACEMENT
1 Disconnect the electrical supply. 2 Remove front casing panel (refer to frame 34). 3 Close off the isolating cocks of the CH circuit at the
bottom of the boiler. 4 Release system pressure by opening the main circuit
drainage cock.
Do not release CH pressure using the pressure relief
valve. It may cause debris within the system to foul
the valve.
5 Remove the CH circuit flow switch (see frame 57). 6 Unscrew the four screws A, open the hydraulic operator
and remove the membrane B. 7 Re---assemble in reverse order.
When assembling the membrane, ensure to place the
do not use
Looking through the switch box B it is possible to verify the position of the spindle C
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.
B
C
A
D
mini HE --- Installation & Servicing40
Page 41
SERVICING
59 DHW FLOW SWITCH REPLACEMENT
1 Disconnect the electrical supply. 2 Remove the front panel of the case (refer to frame 34). 3 Disconnect the connector A and remove the sensor by
pulling it towards the front of the boiler (the sensor is held
in place by means of a spring). 4 Replace the sensor and re--- assemble in reverse order
60 DHW FILTER AND FLOW LIMITER
REPLACEMENT
1 Disconnect the electrical supply. 2 Remove the front panel of the case and empty the DHW
circuit. 3 Remove the flow switch A (see frame 59). 4 Remove the gas valve (see frame 48). 5 Unscrew the plug B and extract the flow switch group. 6 To remove the filter C from the flow switch group separate
the body D from the plug B by unscrewing it. 7 Re---assemble in reverse order.
Return manifold
Spring
Float
Magnetic ring
B --- plug
A --- flow switch
Attention: the magnetic ring has a magnetic polarity and must be correctly coupled with the spindle of the float.
To determine the correct orientation of the ring proceed as follows:
1 Set the function selector of the boiler in stand---by mode.
Threaded ringThreaded ring
Flow limiter
Spring seat
D --- body
C --- filter
A
2 Restore the mains electricity supply to the boiler.
Warning --- ensure that all the electric parts and wiring are dry and do not touch other electric parts during the following operations.
3 Hold the flow switch sensor and bring the ring in contact
with the sensor as illustrated in the following drawing.
4 Observe if the lamp fitted in the sensor body is lit. If not
reverse the ring and repeat the previous operation.
5 Fit the ring on the spindle of the float in the way that lights
the lamp. Ensure filter is correctly positioned and that plug “B” and the threaded ring are screwed tight into the body “D”.
6 Isolate the boiler from the mains electricity supply and
reassemble the parts following the removing sequence in reverse order.
Flow limiter
The mini HE C24 model is factory fitted with a 10 litre/min. flow limiter.
The mini HE C28 model is factory fitted with a 12 litre/min. flow limiter.
Table 8
Nominal flow rate (litres/min)
10 Yellow
12 Brown
1 Disconnect the electrical supply. 2 Remove the front panel of the case and empty the DHW
circuit. 3 Remove the flow switch A (see frame 59). 4 Remove the gas valve (see frame 48). 5 Remove the flow switch group (see frame 60 above) 6 Unscrew the threaded ring and extract the flow limiter.
7 Fit the correct colour coded limiter (see Table 8 above)
and screw the threaded ring tight into the body ’D’. 8 Re---assemble in reverse order.
Colour
SERVICING
mini HE --- Installation & Servicing 41
Page 42
SERVICING
61 PRIMARY HEAT EXCHANGER
REPLACEMENT
1 Disconnect the electrical supply.
2 Remove outer and inner casing as explained in frame 34.
3 Close off the isolating cocks of the CH circuit at the
bottom of the boiler.
4 Release system pressure by opening the main circuit
drainage cock. Do not release CH pressure using the
SERVICING
pressure relief valve. It may cause debris within the system to foul the valve.
5 Remove the combustion chamber panel A by unscrewing
the screws B and removing the fan holder bracket C.
6 Remove the screw D and the plate E.
7 Loosen the connection F and slightly move the pipe G
upwards.
8 Remove the clip H and the safety thermostat I. It is not
necessary to disconnect it from the wiring.
9 Completely unscrew the connection J and move the pipe
K downwards freeing it from the heat exchanger connection.
10 Remove the clip L.
11 Move the pipe M upwards freeing it from the connection
and rotate towards right.
Fit the clip H with the arrow pointing upwards as illustrated in the drawing.
Do not force the connection F when tighting it.
C
B
A
B
D
G
M
F
I
H
K L E
12 Remove the heat exchanger by sliding it forwards.
13 Re --- assemble in reverse order.
62 RECUPERATOR REPLACEMENT
1 Disconnect the electrical supply. 2 Remove outer and inner casing as explained in frame 34. 3 Close off the isolating cocks of the CH circuit at the
bottom of the boiler.
4 Release system pressure by opening the main circuit
drainage cock.
Do not release CH pressure using the pressure relief valve. It may cause debris within the system to foul the valve.
5 Remove the fan A (see frame 51) and the air pressure
switch B (see frame 53).
6 Remove the flue thermostat C (see frame 45) 7 Completely loosen the connection D and slightly move the
pipe E upwards.
8 Remove the clip F and move the pipe G downwards
freeing it from the connection, then turn it towards right.
9 Using pliers, remove the spring H moving it downwards
and disconnect the rubber pipe I.
10 Remove the bracket J by unscrewing the screws that hold
it on the frame.
11 Rotate the recuperator K as indicated by the arrow and
remove it towards the front of the boiler. 12 Remove the clip L and the pipe E. 13 Reassemble the recuperator carrying out the removal
operations in reverse order.
J
mini HE --- Installation & Servicing42
Page 43
SERVICING
After reassembling ensure that the fan ---exchanger and exchanger---elbow gaskets are correctly mounted and ensure a good sealing.
K
C
B
A
J
F
G
SERVICING
L
E
H
I
D
mini HE --- Installation & Servicing 43
Page 44
SERVICING
63 DHW HEAT EXCHANGER
REPLACEMENT
1 Disconnect the electrical supply. 2 Remove outer casing (refer to frame 34). 3 Close the isolating cocks of the CH circuit and DHW
supply at the bottom of the boiler. 4 Release system pressure by opening the main circuit
drainage cock.
Do not release CH pressure using the pressure relief
valve. It may cause debris within the system to foul
the valve.
SERVICING
5 Release the pressure of the DHW circuit by opening a hot
tap. 6 Remove the diverter valve actuator (see frame 64). 7 Completely unscrew the two Allen key screws A which
hold the exchanger to the brass groups.
8 Move the exchanger towards the rear of the boiler and
extract it.
9 Re---assemble in the reverse order.
Attention. When reassembling the exchanger be sure to put the off center location/securing pin indicated towards the left side of the boiler.
A
64 DIVERTER VALVE ACTUATOR
REPLACEMENT
1 Disconnect the electrical supply. 2 Remove front casing panel (refer to frame 34).. 3 Disconnect the connectors A. 4 Remove the fixing spring B and remove the actuator C.
Re --- assemble in reverse order.
When reassembling the actuator, refer to the wiring diagram in frame 23 for the correct wiring connection.
B AC
mini HE --- Installation & Servicing44
Page 45
SERVICING
65 DIVERTER VALVE INTERNAL PARTS
REPLACEMENT
1 Disconnect the electrical supply.
2 Remove front and left hand casing panels (refer to frame
34).
3 Close the isolating cocks of the CH circuit and DHW
supply at the bottom of the boiler.
4 Release system pressure by opening the main circuit
drainage cock.
Do not release CH pressure using the pressure relief
valve. It may cause debris within the system to foul
the valve.
5 Release the pressure of the DHW circuit by opening a hot
tap.
6 Remove the diverter valve actuator (see frame 64).
7 Remove the fork D and remove the primary circuit flow
switch E.
8 Disconnect both CH and DHW thermistors F.
9 Unscrew the connector G, disconnect the CH flow and
DHW outlet isolator valves.
I
J
(rear view) 13 Refer to the following exploded view to remove the
internal parts of the three way diverter valve.
H
SERVICING
G
F F
10 Remove the DHW heat exchanger (see frame 63).
11 Remove the fork H and move away the pipe I.
12 Unscrew the screw J and remove the diverter (flow)
group.
DE
66 PROGRAMMER REPLACEMENT
(if fitted)
1 Disconnect the electrical supply.
2 Gain access to the main control p.c.b. (steps 1 to 4 of
frame 55).
3 Disconnect the wiring at the programmer.
14 Re --- assemble in reverse order.
4 Squeeze the hooks that hold the programmer on the
control panel fascia and withdraw the faulty programmer.
5 Re---assemble in reverse order.
When reassembling the new programmer, refer to the wiring diagram in frame 23 for the correct wiring connection.
6 Replace the panels and check the operation of the new
programmer.
mini HE --- Installation & Servicing 45
Page 46
67 CH DRAIN COCK REPLACEMENT
1 Disconnect the electrical supply
2 Remove front and right hand casing panels
(refer to frame 34).
3 Close off the isolating cocks of the CH circuit at the
bottom of the boiler.
4 Release system pressure by opening the main circuit
drainage cock.
Do not release CH pressure using the pressure relief
valve. It may cause debris within the system to foul
SERVICING
the valve.
5 Remove the CH drain cock A from the return body.
6 Re---assemble in reverse order.
68 CONDENSATE TRAP REPLACEMENT
1 Disconnect the electrical supply
2 Remove front and right hand casing panels
(refer to frame 34).
3 Disconnect the trap from the draining pipe.
4 Using pliers, remove the spring A moving it up-
wards.
SERVICING
A
5 Remove the nut B and lower the trap.
6 Disconnect the wirings from the trap.
7 Reassemble carrying out the removal operations
in reverse order.
AB
mini HE --- Installation & Servicing46
Page 47
FAULT FINDING
(functioncontrolinposition)
.
(functioncontrolinorposition)
---Lackofburnerignition
69 MAIN CONTROL P.C.B.
OPTICAL INFORMATION
The main control p.c.b. is provided with three lamps (L.E.D. indicators) A that give optical information during the normal operation of the boiler or for service and fault fiinding purpose.
Normal operation
The green lamp on the left is directly visible on the control panel fascia and it gives information during the normal operation of the boiler. The other two lamps are normally switched off.
The following table gives the relationship between the visible lamp indication and its meaning.
Boiler in stand--- by condition. (function control in position).
Anti--- freeze system active.
A short pulse every 4 seconds
Boiler ON condition (function control in or
1 second ON 1 second OFF
Faulty boiler or irregular operation as:
Very fast pulses (4 per second)
--- Empty primary circuit
--- No primary circuit flow
--- Lack of burner ignition
--- Excessive temperature in the primary circuit.
--- Dip --- switch 3 left in the OFF position
--- Faulty temperature probe
The following table gives a summary of the relationship between each of the possible lamp combinations and their meaning.
Normally operating boiler
CH operation
DHW operation
Frost protect operation
DHW operation Excessive temperature on primary circuit
Faulty CH temperature probe NTC
Faulty DHW temperature probe NTC
Faulty primary circuit (no water or absence of flow)
Lack of burner ignition (no ignition signal from the full seqence ignition device)
Ignition gas pressure adjustment
Minimum gas pressure adjustment
Lamp
OFF
Lamp
ON
Flashing lamp, alone
or simultaneously
with an other lamp.
Flashing lamp,
alternate with
another lamp.
FAULT FINDING
70 DIVERTER VALVE ACTUATOR
SPINDLE POSITION
To remove the diverter valve actuator refer to frame 64.
The following illustrations indicate the relationship between the electric command coming from the main control p.c.b. and the position of the brass spindle when the boiler operates in either DHW mode or CH mode.
In both figures the relationship between the position of the actuator and the resistance of the motor windings (the motor must be disconnected from the wiring) is also given.
Spindle
visible
3
2
bkbnbu
0 V
CH mode DHW mode
1
Open circuit
9,4 Kohm
bn = brown
230 V
bu = blue bk = black
Spindle fully
retracted
3
bkbnbu
230 V
2
1
0 V
9,4 Kohm
Open circuit
mini HE --- Installation & Servicing
47
Page 48
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Page 49
Continued from page
48 of fault finding
FAULT FINDING
With the boiler and
heating circuit warm
does the burner
pressure reduce if the
heating temperature setting is reduced to
minimum?
yes
When a DHW tap is
opened and the DHW
temperature is set to
maximum, does the water become hot?
yes
no
Is there between 0V dc
and 16V dc at the Grey
and Black connections
on the modulating coil?
(0=min, 16=max)
yes
Repair faulty gas
valve
no no
Is the p.c.b. jumper
in position 8
(Refer to frame 55)
yes
Is the red LED
illuminated on DHW
flow sensor?
yes
Is there 230V
ac between
Blue and
Black at the
3---way valve
connection?
yes
no no
no no
Is the continuity of the
modulator harness
O.K?
yes
Repair faulty PCB
#1
Connect jumper in
position 8.
no no no
Is the
continuity of
the 3---way
valve
harness
O.K?
yes
Is there 5V dc between
Red and Blue on
connecting harness?
Repair or
replace
faulty
wiring
yes
Repair or replace
faulty wiring
Is tharness
continuity O.K?
yes
Repair faulty
PCB #1
Repair or
replace
faulty wiring
FAULT FINDING
Continued on page
54 of fault finding
Remove the
motor
assembly, with
230V at the
connections is
the spindle fully
retracted? Refer
to frame 70.
yes
Replace
faulty valve
body
assembly
no
Repair
faulty
PCB #1
Replace
faulty motor
assembly
Replace the
sensor. Is
red LED
illuminated?
yes
Faulty
sensor
now
replaced
no no
Dismantle the DHW detector
valve and clean.
Refer to frame 60.
Reassemble.
Does the DHW
water become
hot?
yes
Repair or
replace
faulty DHW
detector
valve
mini HE --- Installation & Servicing
49
Page 50
Continued from page 48 of fault
finding. Is the green
LED on front fascia
flashing 4 times per
second?
FAULT FINDING
Access the 4 dip
switches on p.c.b. #1.
Move the #1 dip switch off’ then ’on’. This activates p.c.b.
service mode. Refer to
fault code frame 69. Is
LED 1 flashing with
LED 2 on ?
FAULT FINDING
yes
Is the heating circuit
pressurised to at least 1 bar and fully vented
yes
Remove the pump
nut. Does the pump
rotate freely when
yes
When the pump
runs does the
spindle of the water
flow detector extend to operate the micro switch? Refer to frame 57.
yes
Is there continuity
between C and NO
contacts on micro
switch when the
switch is operated?
of air?
turned)
no
Are LED2 and LED 3
flashing?
Check resistance of
CH thermistor. Is it
between 12 kW and
1.5 kW ?
yes
Repair or replace
faulty wiring
no
Re--- pressurise
system and vent
no
Replace faulty pump
no
Replace faulty
diaphragm and clean
housing of debris, if any.
refer to frame 58.
no
Replace faulty micro
switch
no no
Are LED2 flashing
LED 3 on?
yes
no no
Replace faulty
thermistor
Check resistance of
DHW thermistor. Is
it between 12 kW
and 1.5 kW ?
yes
Repair or replace
faulty wiring
Continued on page
51 of fault finding
Replace faulty
thermistor
yes
Is the continuity of
the micro switch
harness O.K?
yes
Replace faulty PCB
#1
50
no
Repair or replace
faulty wiring
mini HE --- Installation & Servicing
Page 51
FAULT FINDING
Continued from page 50
of fault finding
Are LED 1 and LED 3
flashing with LED 2
on, plus LED 4 on the
Is there > 17 mbar at
the gas valve inlet?
Press reset button. Is
yes
there 230V across the
Black and Blue gas
valve connection
during ignition?
facia on?
yes
yes
no
nono
Rectify gas supply
fault.
no no no no
Is there
230V at
Black and
Blue at
gas valve
harness
connector
on PCB
#2?
yes
Repair or
replace
faulty wiring
Is there 230V
at pin 101
Brown on
connecting
harness at
PCB #2?
yes yes
Is fuse continuity O.K. on PCB #2?
yes
Continued on
page 53 of
fault finding
PCB
Replace faulty PCB #2
Is there 230V
at pin 11
Brown on
PCB
connecting
harness at
PCB #1?
Repair or replace faulty wiring
no
Replace
faulty PCB
#1
Replace
fuse
FAULT FINDING
Is there a burner
pressure during
ignition period?
yes
Is there ignition at the
burner?
yes
Continued on page 52 of
fault finding
Has the main overheat
no no
thermostat operated?
(Check continuity)
yes
Allow boiler to cool
and press re ---set
no no no no
Is a spark
visible at the
burner during
ignition?
yes
Is the ignition burner
pressure correct? Refer
to frame 27.
yes
Ensure the ignition electrode position and spark gaps are correct.
Are the ignition
Has the flue thermostat operated? (Press the thermostat
reset button and/or
Check continuity)
yes
Allow boiler to cool
and press re ---set
leads
disconnected
or damaged
and sparking
to earth?
yes
Replace
faulty
electrode
assy. Make
connection.
no
Adjust ignition burner
pressure
Rectify or replace. Refer to frame 41.
Are the ignition leads correctly
connected to
PCB #2?
yes
Replace
faulty PCB #2
no
Is there continuity of overheat thermostat
wiring at PCB
connection?
Replace faulty gas
yes
valve
Rectify
faulty
connection
no
Repair or replace
damaged wiring
mini HE --- Installation & Servicing
51
Page 52
Continued from page 51
of fault finding
FAULT FINDING
FAULT FINDING
Does the burner
remain alight?
yes
no no
Is the position of the
detection electrode correct, and electrode undamaged? Refer to
frame 41.
yes
Is the resistance of the
detection electrode
assembly < 5W from
tip to connector ?
yes
Is the polarity of
the mains correct?
yes
Is the condense
freely discharged
through the
condensate trap
and pipework?
yes
Replace faulty PCB #2
no
no
no
Rectify electrode
position or replace
faulty electrode.
Is the lead
connected ?
yes
Replace faulty
detection lead assy.
Rectify wiring fault
Check the
condensate trap
and discharge
pipework for
cleaness
no
Connect lead
correctly
Is the burner pressure
within min and max
value* with the boiler
running?
yes
no
Adjust burner pressure.
Refer to frame 27.
Refer back to page 48 of
fault finding to continue.
* see Table 2 at page 4 for the correct value
52
mini HE --- Installation & Servicing
Page 53
FAULT FINDING
Continued from page 51 of fault
finding
Is the fan running?
yes
Is LED 1 on and LED
2 flashing?
Is dip---switch # 3 in
the off position?
Refer to frame 27.
yes
Switch to on position.
no no no
Is there 230V at the
fan connections?
yes
Replace faulty fan.
no
no no
Replace faulty PCB #1
Is there continuity
between NC and C at
the Air Pressure
Switch?
yes
no
Is there continuity of
the Air Pressure
Switch harness?
yes
no no
Is there 230V at
pin 101 PCB # 2?
yes yes
Is LED 1 flashing and
LED 2 and LED 3 on?
yesyes
Is dip---switch # 3 in
the off position?
Refer to frame 27.
yes
Switch to on position.
Replace faulty Air
Pressure Switch.
Repair or replace
faulty wiring.
Are the connections
between PCB # 1 and
PCB # 2 O.K?
Replace faulty PCB #1
Repair or replace
wiring.
FAULT FINDING
Is there continuity
across C and NO on
the Air Pressure
Switch?
yes
Is the Air Pressure
Switch harness
continuity O.K?
yes
Is the burner on?
yes
Repair or replace
faulty flame detection
signal connection
harness. Refer to
frame 41.
no no
Are the sensing pipes
undamaged and
connected?
yes
Is the flue clear and
venturi O.K?
yes
Replace faulty Air
Pressure Switch
no
Repair or replace
faulty wiring.
no
Replace faulty PCB #2
Replace faulty PCB #2 Replace faulty PCB #1
Replace sensing
pipes.
no
Clear flue
Repair or replace
mini HE --- Installation & Servicing
53
Page 54
Continued from
page 49
Is there a temperature rise
of 35 ° C across the DHW
circuit at:
10.0 L/min 24 kW model
11.6 L/min 28 kW model
FAULT FINDING
no no no
Is there max burner pressure* when the
boiler first lights?
yes
Is there > 17 mbar
gas pressure at the
gas inlet?
yes
Rectify gas supply
fault.
FAULT FINDING
yes
no no no
With the DHW hot
does the burner
pressure modulate if
the DHW temperature
setting is reduced to
minimum?
yes yes
Is the maximum water
flow correct
10.0 L/min 24 kW model
12.0 L/min 28 kW model
Is there between 0V dc
and 16V dc at the
Grey and Black
connections on the
modulating coil?
(0=min, 16=max)
Adjust the max setting
on the gas valve. Refer
to frame 27. Check that
max burner pressure*
can be achieved.
Is the cold water supply
adequate? refer to frame
6 and Table 1 at page 4.
yes
Check the DHW inlet
filter. Remove debris
and clean or replace
filter.
Is the continuity of the
modulator harness
O.K?
yes
nono
Rectify water supply
fault.
Repair or replace
faulty wiring.
54
Boiler Operating
Correctly
Replace faulty gas
valve.
Replace faulty PCB
* see Table 2 at page 4 for the correct value
mini HE --- Installation & Servicing
Page 55
The following are parts commonly required as replacements, due to damage or expendability. The failure or absence is likely to affect the safety and/or performance of this appliance.
The list is extracted from the British Gas List of Parts which contains all available spare parts.
The full list is held by British Gas, Caradon Plumbing Ltd. distributors and merchants.
When ordering spares please quote:
1 Boiler model (see Data Plate) 2 Appliance G.C. number (see Data Plate)
3 Description 4 Quantity 5 Product No.
Key No.
1 173---148 Burner (mod. mini HE C24) 1 075427
2 Main heat exchanger + ’O’ rings (mod. mini HE C24) 1 173991
3 Recuperator 1 173993
4 169---069 Injectors for natural gas (mod. mini HE C24) 12 075692
5 H21---048 Fan (mod. mini HE C24) 1 173983
6 E90--- 627 Gas valve + gaskets 1 172611
7 169---127 Air pressure switch (mod. mini HE C24) 1 173236
8 E83--- 013 Safety valve 1 172494
9 Electronic regulation p.c.b. 1 174017
10 E83 --- 142 Full sequence ignition device 1 172548
11 E00 --- 684 Primary circuit flow switch 1 075419
12 E83 --- 082 DHW flow switch (mod. mini HE C24) 1 172503
13 E00 --- 688 Main. flow switch membrane 1 075421
14 E83 --- 101 Overheat thermostat 1 172512
15 E57 --- 048 DHW heat exchanger + ’O’ rings (mod. mini HE C24) 1 075460
16 H20 --- 986 Automatic air purger valve 1 173813
17 Pump + ’O’ rings 1 174004
18 E83 --- 145 Temperature--- pressure gauge 1 172551
19 H21 --- 064 Flue thermostat 1 173985
20 E83 --- 086 Three way diverter valve (electric actuator) 1 172505
21 H21 --- 060 Sealed chamber gaskets kit 1 173986
22 E83 --- 081 Magnetic flow switch and filter 1 172502
23 E83 --- 127 Ignition electrode --- left 1 172533
24 E83 --- 126 Ignition electrode --- right 1 172532
25 E83 --- 122 Detection electrode 1 172531
26 E69 --- 243 Window (glass + rubber frame) 1 170977
27 169 --- 141 1/2” flat gasket 3 075514
28 169 --- 033 3/4” flat gasket 4 075415
29 169 --- 083 Fuse 1,6 A T 1 172562
30 164 --- 026 Temperature probe (main or DHW circuit) 1 172496
31 H21 --- 052 Side case panel 2 173987
G.C. No Description No. Off/
Boiler
173--- 149 Burner (mod. mini HE C28) 1 075535
Main heat exchanger + ’O’ rings (mod. mini HE C28) 1 173992
Injectors for natural gas (mod. mini HE C28) 14
E01---156 Injectors for LPG (mod. mini HE C24) 12 173982
Injectors for LPG (mod. mini HE C28) 14
H21---049 Fan (mod. mini HE C28) 1 173984
H08---605 Air pressure switch (mod. mini HE C28) 1 173136
E57---049 DHW heat exchanger + ’O’ rings (mod. mini HE C28) 1 075540
Product No.
mini HE --- Installation & Servicing
55
Page 56
32
2
3
Control panel door 1 173988
33 Front case panel 1 173989
1
4
5
10
6
7 8
9
22
12
18
19
14
21
20
23 25
24
1511
16
1713
26 27 28
56
29 30
31
32
33
mini HE --- Installation & Servicing
31
Page 57
INSTALLER
NOTIFICATION
GUIDELINES
IT IS A REQUIREMENT OF CORGI MEMBERSHIP
TO REGISTER EVERY GAS APPLIANCE
Install and commission
this appliance to
manufacturers’ instructions
Complete the
Benchmark Checklist
In addition a change to Building Regulations (England and
Wales) requires the installer to notify
when installing a heating appliance, as from 1st April 2005.
Competent Person’s
SELF CERTIFICATION SCHEME
If you notify via CORGI Scheme, CORGI will then notify the Building Control (LABC) who relevant Local
Authority Building Control (LABC)
scheme on members behalf
Scheme members only:
Call CORGI on 0870 88 88 777 or
log onto:
www.corgi---notify.com
within 10 days
You must ensure that the
notification number issued by
CORGI is written onto the
Benchmark Checklist
Choose Buildings
Regulations
notification route
BUILDING CONTROL
Contact your relevant Local
Authority Building Control (LABC)
who will arrange an inspection or
contact a government approved
inspector
LABC will record the data and will
issue a certificate of compliance
CORGI will record the data and will
send a certificate of compliance to
the property
mini HE --- Installation & Servicing
IT IS A CONDITION OF THE
MANUFACTURERS WARRANTY
THAT THE BENCHMARK
COMMISSIONING CHECKLIST IS
FULLY COMPLETED AND LEFT
WITH THE APPLIANCE
57
Page 58
BENCHMARK No.
GAS BOILER COMMISSIONING CHECKLIST
BOILER SERIAL No. NOTIFICATION No.
To comply with the Building Regulations, each section must have a tick in one or other of the boxesCONTROLS
TIME & TEMPERATURE CONTROL TO HEATING TIME & TEMPERATURE CONTROL TO HOT WATER HEATING ZONE VALVES HOT WATERZONE VALVES THERMOSTATIC RADIATORVALVES AUTOMATICBYPASSTO SYSTEM
ROOM T/STAT & PROGRAMMER/TIMER
CYLINDER T/STAT& PROGRAMMER/TIMER
FITTED FITTED NOT REQUIRED FITTED FITTED NOT REQUIRED
PROGRAMMABLE ROOMSTAT
FOR ALL BOILERS CONFIRM THE FOLLOWING
THE SYSTEM HAS BEEN FLUSHED IN ACCORDANCE WITH THE BOILER MANUFACTURER’S INSTRUCTIONS ? THE SYSTEM CLEANER USED THE INHIBITOR USED
FOR THE CENTRAL HEATING MODE, MEASURE & RECORD
GAS RATE BURNER OPERATING PRESSURE (IF APPLICABLE) CENTRAL HEATING FLOW TEMPERATURE CENTRAL HEATING RETURN TEMPERATURE
FOR COMBINATION BOILERS ONLY
COMBI BOILER
NOT REQUIRED
m3/hr ft/hr N/A mbar
°C °C
HAS A WATER SCALE REDUCER BEEN FITTED? WHATTYPE OF SCALE REDUCER HAS BEEN FITTED?
YES NO
FOR THE DOMESTIC HOT WATER MODE, MEASURE & RECORD
GAS RATE MAXIMUMBURNER OPERATING PRESSURE (IF APPLICABLE) COLD WATERINLET TEMPERATURE HOT WATEROUTLET TEMPERATURE WATER FLOW RATE lts/min
m3/hr ft/hr N/A mbar
FOR CONDENSING BOILERS ONLY CONFIRM THE FOLLOWING
THE CONDENSATE DRAIN HAS BEEN INSTALLED IN ACCORDANCE WITH THE MANUFACTURER’S INSTRUCTIONS?
YES
FOR ALL INSTALLATIONS CONFIRM THE FOLLOWING
THE HEATING AND HOT WATER SYSTEM COMPLIES WITH PARTS4 & 7 OF THE BUILDING REGULATIONS
THE APPLIANCE AND ASSOCIATED EQUIPMENT HAS BEEN INSTALLED AND COMMISSIONED IN ACCORDANCE WITH THE MANUFACTURER’S INSTRUCTIONS
IF REQUIRED BY THE MANUFACTURER, HAVE YOU RECORDED A CO/CO2RATIOREADING? CO/CO2RATIOYESN/A THE OPERATION OF THE APPLIANCE AND SYSTEM
CONTROLS HAVE BEEN DEMONSTRATED TOTHE CUSTOMER
°C °C
THE MANUFACTURER’S LITERATUREHAS BEEN LEFT WITH THE CUSTOMER
COMMISSIONING ENG’S NAME
PRINT CORGI ID No. SIGN
DATE
Page 59
SERVICE INTERVAL RECORD
Itisrecommendedthatyour heatingsystem is serviced regularly
and thatyou completetheappropriateService IntervalRecord Below.
Service Provider.Before completing the appropriate Service Interval Record below,please ensure you have carried out the service
as described in the boiler manufacturer’s instructions.Always use themanufacturer’s specifiedspare part when replacing all controls
SERVICE 1
ENGINEER NAME COMPANYNAME TEL No. CORGI ID CARD SERIAL No. COMMENTS
SIGNATURE
SERVICE 3
ENGINEER NAME COMPANYNAME TEL No. CORGI ID CARD SERIAL No. COMMENTS
SIGNATURE
SERVICE 5
ENGINEER NAME COMPANYNAME TEL No. CORGI ID CARD SERIAL No. COMMENTS
DATE
DATE
DATE
SERVICE 2
ENGINEER NAME COMPANYNAME TEL No. CORGI ID CARD SERIAL No. COMMENTS
SIGNATURE
SERVICE 4
ENGINEER NAME COMPANYNAME TEL No. CORGI ID CARD SERIAL No. COMMENTS
SIGNATURE
SERVICE 6
ENGINEER NAME COMPANYNAME TEL No. CORGI ID CARD SERIAL No. COMMENTS
DATE
DATE
DATE
SIGNATURE
SERVICE 7
ENGINEER NAME COMPANYNAME TEL No. CORGI ID CARD SERIAL No. COMMENTS
SIGNATURE
SERVICE 9
ENGINEER NAME COMPANYNAME TEL No. CORGI ID CARD SERIAL No. COMMENTS
SIGNATURE
DATE
DATE
SIGNATURE
SERVICE 8
ENGINEER NAME COMPANYNAME TEL No. CORGI ID CARD SERIAL No. COMMENTS
SIGNATURE
SERVICE 10
ENGINEER NAME COMPANYNAME TEL No. CORGI ID CARD SERIAL No. COMMENTS
SIGNATURE
DATE
DATE
Page 60
Technical Training
The Ideal Boilers Technical Training Centre offers a series of first class training courses for domestic, commercial and industrial heating installers engineers and system specifiers.
For details of courses please ring: 01482 498 432. . . . . . .
commissioning & servicing of central heating systems
the code of practice for the installation
Ideal boilers
P.O. Box 103, National Ave, Kingston upon Hull HU5 4JN. Telephone: 01482 492 251 Fax: 01482 448 858. Registration No. London 322 137
Caradon Ideal Limited pursues a policy of continuing improvement in the design and performance of its products. The right is therefore reserved to vary specification without notice.
Ideal Installer/Technical Helpline: 01482 498 663
www.idealboilers.com
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