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Keston Combi 35kw User's Manual
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72 Pages
Keston Combi 35kw is a high-efficiency condensing combination gas boiler that provides both central heating and instant domestic hot water. With a central heating output range of 7.1 to 25.6 kW and a maximum domestic hot water output of 35.3 kW, it's ideal for medium to large-sized homes. The boiler is SEDBUK 2009 A-rated for energy efficiency, helping you save money on your energy bills. It also features a built-in frost protection system to prevent freezing during cold weather.
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Combi 30 & 35
Installation and Servicing Instructions
FAN POWERED HIGH EFFICIENCY
MODULATING DOMESTIC CONDENSING
GAS COMBINATION BOILER
CE/PI No. 86-CL-38
Combi 30 - GC No. 47-930-04
Combi 35 - GC No. 47-930-05
These instructions must be left either with the user or next to the site gas meter.
Keston Heating
PO Box 103, National Avenue, Kingston Upon Hull, HU5 4JN
Tel. +44 (0) 1482 443005 Fax. +44 (0) 1482 467133 email : [email protected] web : www.keston.co.uk
COMPLIANT WITH BUILDING REGULATION PART L1 & L2
SEDBUK A RATED
2 Keston Combi - Installation and Servicing
NOTEs FOR ThE INsTALLER
FOR ANy TEChNICAL qUERIEs pLEAsE RINg ThE KEsTON
INsTALLER/TEChNICAL hELpLINE : 01482 443005
NOTE. BOILER REsET pROCEDURE -
To reset boiler, turn mode knob to reset position and immediately turn knob back to required setting.
The boiler will repeat the ignition sequence if a heat demand is present.
DOCUMENT AMENDMENTs
Relevant Installation changes implemented in this book from Mod Level ..... A02 (Oct 12) and A03 (Feb 14) page 11
Water Treatment - Addition of Adey Professional Heating Solutions page 31
Item “3” added to Electrical Installation
Statement added ref to commissioning process of combustion page 67
New Page Added - Benchmark Commissiong & Servicing Section page 68 & 69
New updated Commissioning Checklist & Service Record Sheets page 70 & 71
New pages added, Flowchart for CO Level and Combustion Ratio Check on Commissioning a Condensing Boiler
Keston reserve the right to vary specification without notice
Keston Combi - Installation and Servicing 3
general
Table 1 - general Data
Keston Combi
Gas supply
Gas Supply Connection
Injector Size
Inlet Connection
(mm)
DHW
Outlet Connection
Flow Connection
Return Connection
Flue Terminal Diameter
Average Flue Temp-Mass Flow Rate
Maximum Working Pressure (Sealed Systems)
Maximum Domestic Hot Water Inlet Pressure
Packaged Weight
Maximum Installation Weight
Boiler Casing Size
DHW
CH
CH mm (in)
(DHW) bar (lb/in 2 ) bar (lb/in 2 )
bar (lb/in 2 ) Minimum Domestic Hot Water Inlet Pressure*
Electrical Supply
Power Consumption
Fuse Rating
Water content
W
CH litre (gal)
DHW litre (gal) kg (lb)
Height
Width
Depth kg (lb) mm (in) mm (in) mm (in)
*Required for maximum flow rate. Boiler operates down to 2 l/min DHW delivery
** In areas of low water pressure the DHW restrictor can be removed
30 35
2H - G20 - 20mbar
15mm copper compression
4.65
4.9
15mm copper compression
15mm copper compression
22mm copper compression
22mm copper compression
50 (nominal)
68 o C - 13g/s 73ºC - 15g/s
2.5 (36.3)
10.0 (145)
1.3 (18.9) 1.3 (18.9)**
230 V ~ 50 Hz.
152 177
External : 3A Internal : T4H HRC L250 V
1.2 (0.26)
0.5 (0.11)
37.8 (83.3)
32.8 (72.3)
38 (83.8)
33 (72.8)
700 (27.5)
395 (15.5)
278 (11)
Table 2 - performance Data - Central heating
Boiler Input :
Boiler Input ‘Q’
Gas Consumption
Nett CV
Gross CV kW
(Btu/h) kW
(Btu/h) m 3 /h
(ft 3 /h)
Boiler Output :
Non Condensing
70 o C Mean Water temp.
Condensing
40 o C Mean Water temp.
Seasonal efficiency*
NOx Classification
Max.
24.3
(82,900)
27.0
(92,000)
2.512
(89)
Min. 30
6.1
(20,700)
6.7
(23,000)
0.623
(22) kW
(Btu/h)
24.2
(82,600) kW 25.6
(Btu/h) (87,400)
SEDBUK 2005
6.1
(20,700)
6.4
(21,800)
91.1%
SEDBUK 2009
CLASS 5
89%
Min. 35
7.1
(24,100)
7.9
(26,900)
0.734
(25.9)
7.1
(24,100)
7.5
(25,500)
91%
88.9%
Table 3 - performance Data - Domestic hot Water
Maximum DHW Input :
Gas Consumption
Maximum
DHW Output
DHW Flow Rate at 35°C temp. rise.
DHW Specific Rate
Nett CV
Gross CV kW
(Btu/h) kW
(Btu/h) m 3 /h
(ft 3 /h) kW
(Btu/h) l/min
(gpm) l/min
(gpm)
30
30.4
(103,600)
33.7
(115,000)
3.135
(111)
30.3
(103,300)
12.4
(2.8)
14.5
(3.2)
35
35.4
(120,900)
39.3
(134,200)
3.658
(129)
35.3
(120,500)
14.5
(3.2)
16.9
(3.7)
* 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.
Note. Gas consumption is calculated using a calorific value of 38.7 MJ/m 3 (1038 Btu/ft 3 ) gross or 34.9 MJ/m 3 (935 Btu/ft 3 ) nett
Key to symbols
pMs = Maximum operating pressure of water
To obtain the gas consumption at a different calorific value:
C
13
C
53
= A room sealed appliance designed for connection via ducts to a horizontal terminal, which admits fresh air to the burner and discharges the products of combustion to the outside. The fan is up stream of the combustion chamber.
a. For l/s - divide the gross heat input
(kW) by the gross C.V. of the gas (MJ/m 3 )
b. For ft 3 /h - divide the gross heat input (Btu/h) by the gross C.V. of the gas (Btu/ft 3 )
c. For m 3 /h - multiply l/s by 3.6.
I
2h
= An appliance designed for use on 2nd Family gas, Group H only.
4 Keston Combi - Installation and Servicing
KEsTON Combi 30 & 35
Natural gas only
Boiler size g.C. Appliance No.
(Benchmark No.)
30
35
47-930-04
47-930-05 pI No.
86 CL 38
86 CL 38 general
CONTENTs
Benchmark Commissioning Checklist ..................... 66
Boiler Clearances ......................................................... 9
Boiler Exploded Diagram ........................................... 12
Condensate Drain .......................................... 8,22,23,39
Electrical Connections ............................................... 25
Electrical supply ........................................................... 8
Fault Finding .......................................................... 57-63
Flue system ........................................................... 14-17
gas safety Regulations ............................................... 7
gas supply .................................................................... 8
Installation .............................................................. 12-36
pump ........................................................................... 50
safe handling ................................................................ 6
servicing ................................................................ 37-56
short List of parts ...................................................... 64
Thermostatic Radiator Valves ..................................... 8
Water and systems .......................................... 8, 10-11
Water Connections ..................................................... 24
Water Treatment .........................................................11
Wiring Diagram ........................................................... 30
For GB, to comply with Building Regulations Part L1 (Part 6 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.
Before installing this boiler, read the Code of Practice sheet at the rear of this book.
BENChMARK COMMIssIONINg ChECKLIsT DETAILs
B
oiler page
Make and model ......................................................... 5
Appliance serial no. on data badge .......... Front Cover
SEDBUK No. % .......................................................... 4
Controls
Time and temperature control to heating ................. 26
Time and temperature control to hot water ............. 26
Heating zone valves ................................................n/a
TRV’s.......................................................................... 8
Auto bypass ............................................................... 8
Boiler interlock ............................................................ 8
For .................................................................... all boilers
Flushing to BS.7593 ................................................. 11
Inhibitor .................................................................... 11
Central heating mode
Heat input ...................................................to be calculated page
Burner operating pressure ...................................... n/a
Central heating flow temp. ...........measure and record
Central heating return temp. ........measure and record
For combination boilers only
Scale reducer ........................................................... 11
Hot water mode
Heat input ............................................to be calculated
Max. operating burner pressure .............................. n/a
Max. operating water pressure ........ measure & record
Cold water inlet temp ...................... measure & record
Hot water outlet temp. ..................... measure & record
Water flow rate at max. setting ........ measure & record
For condensing boilers only
Condensate drain ..................................................... 22
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
Keston Combi - Installation and Servicing 5
general
INTRODUCTION
The Keston Combi boiler is a wall mounted, full sequence, automatic spark ignition, low water content, fanned flue, high efficiency, condensing, combination gas boiler.
Note. Due to the high efficiency of the boiler a plume of water vapour will form at the terminal during operation.
Central heating (CH) output is fully modulating with a range of:
30 6.1 to 24.2kW (20,700 to 82,600 Btu/h)
35 7.1 to 24.2kW (24,100 to 82,600 Btu/h)
Instantaneous domestic hot water (DHW) output is also fully modulating with a maximum of :
30 30.3kW (103,300 Btu/h)
35 35.3kW (120,500 Btu/h)
The boiler is supplied fully assembled with DHW plate heat exchanger, diverter valve, circulating pump, pressure gauge, safety valve and CH expansion vessel.
Variable CH and DHW temperature controls are fitted on the user control and the boiler features a DHW preheat facility.
-
-
-
The boiler includes as standard:
- Automatic bypass
Boiler frost protection
Daily pump and diverter valve exercise.
Weather Compensation Kit
The boiler casing is of white painted mild steel.
The boiler temperature controls are visible located in the control panel on the front of the boiler.
The heat exchanger is manufactured from cast aluminium.
The boiler is suitable for connection to fully pumped, sealed heating systems ONLY. Adequate arrangements for completely draining the system by provision of drain cocks MUST be provided in the installation pipework.
Pipework from the boiler is routed downwards.
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. Manoeuvring 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:
• Grip the boiler at the base.
• Be physically capable.
• Use personal protective equipment as appropriate, e.g. gloves, safety footwear.
During all manoeuvres and handling actions, every attempt should be made to ensure the following unless unavoidable and/or the weight is light.
• Keep back straight.
• Avoid twisting at the waist.
• Avoid upper body/top heavy bending.
• Always grip with the palm of the hand.
• Use designated hand holds.
• Keep load as close to the body as possible.
• Always use assistance if required.
OpTIONAL ExTRA KITs
• Electronic Timer (7 day) kit
• Electronic programmable Room Thermostat kit
• stand Off kit
• Air Terminal Finishing Kit
• Flue Sleeve Kit
OpERATION
With no demand for CH, the boiler fires only when DHW is drawn off, or periodically for a few seconds without any DHW draw-off, in order to maintain the DHW calorifier in a heated condition. This only occurs if pre-heat knob is in the ‘ON’ period.
When there is a demand for CH, the heating system is supplied at the selected temperature of between 45 o C and 83 o C, until DHW is drawn off. The full output from the boiler is then directed via the diverter valve to the plate heat exchanger to supply a nominal
DHW draw-off of:
30 12.4 l/min at 35 o C temperature rise.
35 14.5 l/min at 35 o C temperature rise.
When using the outside sensor provided please refer to page 27.
The DHW draw off rate specified above is the nominal that the boiler flow regulator will give. Due to system variations and seasonal temperature fluctuations DHW flow rates/temperature rise will vary, requiring adjustment at the draw off tap.
At low DHW draw-off rate the maximum temperature is limited to
64 o C by the modulating gas control.
The boiler features a comprehensive diagnostic system which gives detailed information on the boiler status when operating, and performance of key components to aid commissioning and fault finding.
6 Keston Combi - Installation and Servicing
general 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 Gas Safe
Registered Engineer. It must be carried out in accordance with the relevant requirements of the:
• Gas Safety (Installation and Use) Regulations
• The appropriate Building Regulations either The Building
Regulations, The Building Regulations (Scotland), Building
Regulations (Northern Ireland).
• The Water Fittings Regulations or Water byelaws in Scotland.
• 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 Registered Gas
Installer (RGII) 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).
BsEN. 12828:2003 Heating Systems in buildings: Design for water based heating systems.
BsEN 12831:2003 Heating Systems in buildings: Method for calculation of the design heat load.
BsEN 14336:2004 Heating Systems in buildings: Installation and commissioning of water based heating systems.
Bs. 5546 Installation of gas hot water supplies for domestic purposes (2nd Family Gases)
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 manufacturer’s 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 these Installation and Servicing Instructions or as otherwise recommended by Keston in writing. If in doubt please enquire.
Any direct connection of a control device not approved by Keston 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
No asbestos, mercury or CFCs are included in any part of the boiler or its manufacture.
Keston Combi - Installation and Servicing
LOCATION OF BOILER
The boiler must be installed on a flat and vertical internal 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.
For electrical safety reasons there must be no access available from the back of the boiler.
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 Engineering document
IGE/UP/7:2006 Edition 2.
Bathroom Installations
This appliance is rated Ip20.
The boiler may be installed in any room or internal space, although particular attention is drawn to the requirements of the current
IEE (BS.7671) Wiring Regulations and 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 IE reference should be made to the current
ETCI rules for electrical installations and I.S. 813:2002.
If the appliance is to be installed in a room containing a bath or shower then, providing water jets are not going to be used for cleaning purposes (as in communal baths/showers), the appliance must be installed beyond Zone 2, as detailed in BS.7671.
2.25m
Zone 1
Zone 0
0.6m
Recessed window
Zone 2
Ceiling
3G8913a
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 airing cupboard installation, are to conform to the following:
• BS 6798 (No cupboard ventilation is required - see ‘Air Supply’ for details).
• The position selected for installation MUST allow adequate space for servicing in front of the boiler.
• For the minimum clearances required for safety and subsequent service, see the wall mounting template and
Frame 1. In addition, sufficient space may be required to allow lifting access to the wall mounting plate.
• The boiler must be installed on a fire resistant surface.
7
general gAs sUppLy
The local gas supplier should be consulted, at the installation planning 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.
The boiler MUST be installed on a gas supply with a governed meter only.
A gas meter can only be connected by the local gas supplier or by a Gas Safe Registered Engineer. In IE by a Registered Gas
Installer (RGII).
An existing meter should be checked, preferably by the gas supplier, to ensure that the meter is adequate to deal with the rate of gas supply required.
It is the responsibility of the Gas Installer to size the gas installation pipework in accordance with BS6891:2005. Whilst the principle of the 1:1 gas valve ensures the Keston Combi range is able to deliver its full output at inlet pressures as low as 14mb, other gas appliances in the property may not be as tolerant.
When operating pressures are found to be below the minimum meter outlet of 19mb these should be checked to ensure this is adequate for correct and safe operation.
Allowing for the acceptable pressure loss of 1mb across the installation pipework, it can be assumed that a minimum permitted operating pressure of 18mb will be delivered to the inlet of the appliance. (Reference BS 6400-1 Clause 6.2 Pressure
Absorption).
The external gas cock could further reduce the operating pressure when measured at its test point. The pressure drop is relative to the heat input to the boiler (kW), refer to graph below.
WATER CIRCULATION sysTEM
IMpORTANT.
A minimum length of 1 metre of copper pipe MUST be fitted to both flow and return connections from the boiler before connection to any plastic piping.
The central heating system should be in accordance with BS.6798 and, in addition, for smallbore and microbore systems, BS.5449.
WATER TREATMENT - see Frame 5
BOILER CONTROL INTERLOCKs
Central heating systems controls should be installed to ensure the boiler is switched off when there is no demand for heating, in compliance with Building Regulations.
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.
When thermostatic radiator valves are used, the space heating temperature control over a living / dining area or hallway having a heating requirement of at least 10% of the minimum boiler heat output should be achieved using a room thermostat, whilst other rooms are individually controlled by thermostatic radiator valves.
However, if the system employs thermostatic radiator valves on all radiators, or two port valves, then a bypass circuit must be fitted with an automatic bypass valve to ensure a flow of water should all valves be in the closed position.
ELECTRICAL sUppLy
Warning.
This appliance must be 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 IE reference should be made to the current ETCI rules for electrical installations.
The mains supply to the boiler and system wiring centre shall be through one common fused double pole isolator and for new heating systems, and where practical replacement boiler installations, the isolator shall be situated adjacent to the appliance.
IMpORTANT.
Installation pipes must be fitted in accordance with BS.6891. In IE refer to IS.813:2002.
The complete installation MUST be tested for gas tightness and purged as described in the above code.
CONDENsATE DRAIN
Refer to Frames 20 & 21
A condensate drain is provided on the boiler. This drain must be connected to a drainage point on site. All pipework and fittings in the condensate drainage system MUST be made of plastic - no other materials may be used.
IMpORTANT.
Any external runs must be in accordance with BS 6798.
The drain outlet on the boiler is sized for standard 21.5mm (3/4”) overflow pipe. It is a universal fitting to allow use of different brands of pipework.
8 Keston Combi - Installation and Servicing
general
1 BOILER DIMENsIONs, sERVICEs & CLEARANCEs
The boiler connections are made on the boiler connection tails.
Refer to Frame 22.
The following minimum clearances must be maintained for operation and servicing.
Additional space will be required for installation, depending upon site conditions.
all dimensions in mm
2.5
Air Flue
2.5
from case
62
395
198
30mm
Minimum Top Clearance
155
89
700
395
400
100
*
43 65 57 38 39 65
Gas Inlet
Front clearance
The minimum front clearance when built in to a cupboard is 5mm from the cupboard door but 450mm overall clearance is still required, with the cupboard door open, to allow for servicing.
*
Bottom clearance
Bottom clearance after installation can be reduced to 5mm.
This must be obtained with an easily removable panel, to enable the consumer to view the system pressure gauge, and to provide the 100mm clearance required for servicing.
Keston Combi - Installation and Servicing 9
general
2 sysTEM REqUIREMENTs - Central heating
Notes
a. The method of filling, refilling, topping up or flushing sealed primary hot water circuits from the mains via a temporary hose connection is only allowed if acceptable to the local water authority.
b. Antifreeze fluid, corrosion and scale inhibitor fluids suitable for use with boilers having aluminium heat exchangers may be used in the central heating system.
safety valve setting
Vessel charge pressure bar bar
system pre-charge pressure bar system volume
(litres)
25
50
75
100
125
150
175
190
200
250
300
For other system volumes multiply by the factor access
3.1
4.7
6.3
7.8
9.4
10.9
11.9
12.5
15.6
18.8
3.0
0.5 to 0.75
None 1.0
Expansion vessel volume (litres)
1.6
1.8
3.7
5.5
7.4
9.2
11.0
12.9
14.0
14.7
18.4
22.1
general
1. The installation must comply with all relevant national and local regulations.
2. The installation should be designed to work with flow temperatures of up to 86 o C.
3. All components of the system must be suitable for a working pressure of 3 bar and temperature of 110 o 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 preset lift pressure of 3 bar.
c. Pressure gauge, covering a range of 0 to 4 bar.
d. An 8-litre expansion vessel, with an initial charge pressure of 0.75 bar.
4. ‘Make-up’ Water. Provision must be made for replacing water loss from the system, either :
a. From a manually filled ‘make-up’ vessel with a readily visible water level. The vessel should be mounted at least 150mm above the highest point of the system and be connected through a non-return valve to the system, fitted at least
150mm below the ‘make-up’ vessel on the return side of the radiators. or
b. Where access to a ‘make-up’ vessel would be difficult, by pre-pressurisation of the system.
The maximum cold water capacity of the system should not exceed 143 litres, if not pressurized. However, if the system is to be pressurized, the efficiency of the expansion vessel will be reduced and a larger vessel
(or smaller system volume) may be necessary. If the capacity of the vessel is not considered sufficient for this, or for any other reason, an additional vessel MUST be installed on the RETURN to the boiler.
Guidance on vessel sizing is given in Table above.
Water Flow Rate and pressure Loss
Max CH Output
Water flow rate
Temperature Differential
Head available for system kW
(Btu/h) l/min
(gal/min)
( o o C
F) m.w.g.
(ft.w.g.)
0.063
24.2
(82,600)
17.3
(3.8)
20
(36)
3.4
(11.1)
0.074
5. Filling
The system may be filled by the following method:
Where the mains pressure is excessive a pressure reducing valve must be used to facilitate filling.
a. Thoroughly flush out the whole system with cold water.
b. Fill and vent the system until the pressure gauge registers 1bar and examine for leaks. Refer to Frame
22 for filling detail.
c. Check the operation of the safety valve by raising the water pressure until the valve lifts. This should occur within 0.3bar of the preset lift pressure.
d. Release water from the system until the
minimum system design pressure is reached;
1.0 bar if the system is to be pre-pressurised.
10 continued . . . . . .
Keston Combi - Installation and Servicing
general
3 sysTEM REqUIREMENTs cont’d
DOMEsTIC hOT WATER
1. The domestic hot water service must be in accordance with
BS 5546 and BS 6700.
2. Refer to Table 1 for minimum and maximum working pressures. In areas of low mains water pressures the domestic hot water regulator may be removed from the DHW flow turbine cartridge. Refer to Frame 70. The boiler will require the flow rate to be set to obtain a temperature rise of
35 o C at the tap furthest from the boiler.
3. The boiler is suitable for connection to most types of washing machine and dishwasher appliances.
4. When connecting to suitable showers, ensure that:
a. The cold inlet to the boiler is fitted with an approved antivacuum or syphon non-return valve.
b. Hot and cold water supplies to the shower are of equal pressure.
5. hard Water Areas
Where the water hardness exceeds 200mg/litre, it is recommended that a proprietary scale reducing device is fitted into the boiler cold supply within the requirements of the local water company.
IMpORTANT
Provision MUST be made to accommodate the expansion of DHW contained within the appliance, if a non-return valve is fitted to the
DHW inlet, or a water meter with a non-return valve is installed.
Cold water rising main and pipework in exposed areas need to be suitably lagged to prevent freezing.
4 sysTEM BALANCINg
The boiler does not normally need a bypass but at least some radiators on the heating circuit, of load of at least
10% of the minimum boiler output, must be provided with twin lockshield valves so that this minimum heating load is always available. See note regarding thermostatic radiator valves on page 8.
Note. Systems incorporating zone valves which could completely cut off the flow through the system must also include a bypass.
BALANCINg
1. Set the programmer to ON.
Close the manual or thermostatic valves on all radiators, leaving the twin lockshield valves (on the radiators referred to above) in the OPEN position.
Turn up the room thermostat and adjust the lockshield valve to give an uninterrupted flow through the radiator.
These valves should now be left as set.
2. Open all manual or thermostatic radiator valves and adjust the lockshield valves on the remaining radiators, to give around 20 o C temperature drop at each radiator.
3. Adjust the room thermostat and programmer to
NORMAL settings.
5 WATER TREATMENT
CENTRAL hEATINg
The Keston Combi range boiler has an ALUMINIUM alloy heat exchanger.
IMpORTANT.
The application of any other treatment to this product may render the guarantee of Keston Invalid.
Keston recommend Water Treatment in accordance with the
Benchmark Guidance Notes on Water Treatment in Central
Heating Systems.
If water treatment is used Keston recommend only the use of SCALEMASTER GOLD 100, FERNOx, MBI, ADEY MC1 or
SENTINEL x100 inhibitors and associated water treatment products, which must be used in accordance with the manufacturers’ instructions.
Notes.
1. It is most important that the correct concentration of the water treatment products is maintained in accordance with the manufacturers’ instructions.
2. If the boiler is installed in an existing system any unsuitable additives MUST be removed by thorough cleansing. BS 7593:2006 details the steps necessary to clean a domestic heating system.
3. In hard water areas, treatment to prevent lime scale may be necessary - however the use of artificially softened water is NOT permitted.
4. Under no circumstances should the boiler be fired before the system has been thoroughly flushed.
DOMEsTIC hOT WATER
In hard water areas where mains water can exceed 200ppm
Total Hardness (as defined by BS 7593:2006 Table 2) a scale reducing device should be fitted into the boiler cold supply within the requirements of the local water company. The use of artificially softened water, however, is not permitted.
Keston recommend the use of Fernox Quantomat, Sentinel
Combiguard or Calmag CalPhos I scale reducing devices together with scalemaster in-line scale inhibitor branded Ideal, which must be used in accordance with the manufacturers’ instructions.
For further information contact:
Fernox Cookson Electronics
Forsyth Road, Sheerwater, Woking, Surrey GU21 5RZ
+44 (0) 870 601 500 sentinel performance solutions
The Heath Business & Technical Park, Runcorn, Cheshire WA7 4Qx
Tel: 0800 389 4670 www.sentinel-solutions.net
scalemaster Water Treatment products
Emerald Way, Stone, Staffordshire ST15 0SR
Tel: +44 (0) 1785 811636
Calmag Ltd.
Unit 3-6, Crown Works, Bradford Road, Sandbeds, Keighley,
West Yorkshire BD20 5LN
Tel: +44 (0) 1535 210 320
Adey professional heating solutions
Gloucester Road, Cheltenham GL51 8NR
Tel: +44 (0) 1242 546700
Keston Combi - Installation and Servicing 11
INSTALLATION
6 BOILER AssEMBLy - Exploded View
104 CH Return Valve
105 CH Flow Valve
106 DHW Inlet & Outlet
107 Filling Loop
108 Pump Head
110 Air Vent Pump
111 Diverter Valve Head
112 Diverter Valve Cartdrige
113 Pressure Relief Valve
114 Pipe - PRV Outlet
115 Pipe - Flow
116 Pipe - Return
117 Pipe - Expansion Vessel
118 Expansion Vessel
119 Return Group Manifold
120 Flow Group Manifold
121 Plate Heat Exchanger
127 Flow Sensor Hall Effect
128 Flow Turbine Cartridge
131 Water Pressure Transducer
135 Pressure Gauge
136 Safety Valve Drain Pipe
203 Gas Cock
204 Pipe - Gas Inlet
205 Gas Valve
206 Pipe - Gas Injector
211 Injector Assembly
214 Venturi
215 Fan
217 Burner
218 Gasket - Burner
219 Sump Clean Out Cover
223 Flue Manifold
224 Flue Manifold Top
227 Clamp Retaining Flue Turret
228 Hose Condensate Internal
229 Siphon Trap
231 Condensate Outlet Connection
301 Ctrs Box Fixings Hinge & Spring
302 Primary PCB*
303 CUI Board
304 Control Thermistor (Return)
306 Electrode Ignition
307 Electrode Detection
308 Igniter Unit
504
227
224
309 Thermistor No Flow
313 Ignition Lead
314 Control Box Lens
324 Controls Box Lid
325 Control Box Front
326 Programmer Insert
332 Flue Thermostat
401 Heat Engine
503 Wall Mounting Bracket
504 Front Panel
505 Fascia
506 Bracket - Gas Valve
507 Bracket - Exp. Vessel
136 Safety Valve Drain Pipe
512 Drop Down Door
332 Flue Thermostat
* Note that production boiler PCBs are factory pre-set to operate for boiler range and output. When ordering Primary PCB as a spare, an additional Boiler Chip Card
(BCC) MUST also be purchased for your specific boiler range and output.
Check boiler serial letter code on data plate to obtain correct BCC.
505
503
12
512
313
215
211
308
217
309
306
214
206
205
204
223
218
401
507
118
506
115
332
314
326
303
307
116
301
219
304
229
325
228 112
231
121
120
128
131
127
136
113
119
111
105
108
110
106
203
106
104
117
114
324
135
302
107
*
Keston Combi - Installation and Servicing
7 UNpACKINg
Unpack and check the contents.
pack 1 Contents
A Boiler
B Hardware Pack Box
C Wall Mounting Plate
D These Installation Instructions
E Wall Mounting Template
(located on internal protective packaging)
F Turret Clamp
G Safety Valve Drain Pipe
H Boiler Guarantee / Registration pack
INSTALLATION
A
C
D
B
G
E
F
H
Boiler Guarantee
HARDWARE PACK CONTENTS
Gas Valve Pack
1. Pipe - Gas Inlet
2. Washer - Gas (blue)
3. Gas Cock
Filling Loop Pack
1. 3/8" Fibre washer (x4)
2. Valve (double check valve) fitting
3. Valve - Filling Loop
4. Plastic Chain (x2)
5. Filling Loop
6. 3/8" Blanking Rubber Washer (x2)
Return Valve Pack
1. Pipe CH Return
2. Washer CH
3. Valve Return
DHW Pack
1. Pipe DHW Outlet
2. Valve - Return DHW
3. Washer DHW (x2)
4. Pipe DHW Inlet
5. Nut 1/2"
Accessory Pack
1. Screw (x2)
2. Wallplug (x2)
3. Turret Clamp Screw (x1)
Flow Valve Pack
1. Pipe CH Flow
2. Washer CH
3. Valve Flow (with gauge)
Flue pack Contents
A Flue Adaptor
B Air Spigot
C Terminals - 2 off
D Flue Sleeve
E Wall Plate
F Wall Seal
G Outside Sensor
H Screws - 4 off
J Wall Plugs - 4 off
Gas Valve Pack
1
2
Filling Loop
2
1
6
4
Return Valve Pack
3
1
2
3
3
5
DHW Pack
1
2
3
4
3
Accessory Pack
1
2
3
5
Flow Valve Pack
1
2
3
Keston Combi - Installation and Servicing continued . . . . .
13
14
INSTALLATION
8 FLUE sysTEM
IMpORTANT
When installing a replacement boiler a new flue system must be used. DO NOT re-use the existing boiler flue installation.
DEsIgN
Individual air supply and flue outlet pipes are used as standard.
The material approved for this application is which MUsT be used is:
Marley mupVC solvent Weld system (50mm) and polypipe system 2000 mupVC solvent weld
(50mm), to Bs5255 and/or BsEN1566-11 and BsEN1329, are the only systems approved for this application.
The following pipe and fittings are approved.
polypipe system 2000 mupVC solvent Weld system (50mm) poly pipe Code
MU 301 4m length muPVC wastepipe 5/225
MU 313
MU 314
MU 310
MU 316
50mm x 45 deg muPVC obtuse bend
50mm x 92.5 deg muPVC swept bend
50mm muPVC straigh coupling
50mm x 92.5 deg muPVC swept pipe
Marley mupVC solvent Weld system (50mm)
Marley Code
KP 304
KP32
50mm x 4m double spigot pipe
50mm x 45 deg bend
KSC3
KB3
KT3
50mm straight coupling
50mm x 88.5 deg bend
50mm swept tee
Consideration MUST be given to expansion and contraction of the flue. Refer to Assembly Practice Frame in this installation and
Servicing Instructions for further guidance.
continued............
Keston Combi - Installation and Servicing
INSTALLATION
9 FLUE sysTEM.... CONT’D
TERMINATION OF ThE FLUE AND AIR
The flue and air pipes may terminate independently through any external walls within the same dwelling except on opposing walls, within the maximum lengths shown in graph below.
The air pipe must have an elbow and 150mm length of pipe directed downwards with a termination grill fitted.
The air pipe can be situated at the side or beneath the flue pipe to a minimum dimension of 140mm (see diagram below). It must not be sited above the flue pipe.
The flue and air pipes must extend by at least 40mm from the wall surface.
Condensing boiler emit a visible plume of water vapour from the flue terminal, this is normal. It is the responsibility of the installer to judiciously select a terminal location that does not cause a nuisance.
If either the flue or air terminal is below a height of 2m from ground level a terminal guard must be fitted.
Acceptable range of air pipe siting
TERMINAL POSITIONS
Flue
Pipe
Minimum Separation
140mm
Air Pipe
Terminal
Elbow
MAxIMUM LENgThs
Due to the resistance presented by extended flue length a slight reduction in maximum boiler output will occur where combined flue and air lengths in excess of 18.0m and 16.0m (50mm muPVC) are used. In such cases the boiler output will be reduced by 0.6% and 0.8% per additional metre.
The maximum lengths of both air inlet pipe and flue outlet pipe, when no bends are used, are as detailed in graphs below.
However, each bend used has an equivalent length that must be deducted from the maximum straight length stated in graphs below. Knuckle bends must not be fitted.
A 92.5º swept elbow is equivalent to 1.0m straight length. A 45º bend is equivalent to 0.5m straight length.
It is possible to have variable flue and air lengths as described within the shaded area of graphs below.
sLOpE
‘Horizontal’ flue outlet pipework MUST slope at least 1.5 degrees (26mm per metre run) downwards towards the boiler. Pipework can be vertical. Only swept elbows can be used.
Air inlet pipework can be truly horizontal or vertical, or sloping in a downward direction towards the boiler but in each case rain, etc.,
must be prevented from entering the pipe. There must be no troughs in any of the pipework, whether it be air inlet or flue outlet.
Keston Combi - Installation and Servicing 15
INSTALLATION
10 FLUE INsTALLATION ExAMpLE KEsTON COMBI 30
4m
6m
2m 1.5m
1m
1.5º back to boiler
Sleeve
Bracket at each 1 metre
1.5º back to boiler
6m
0.15m
38
34
Keston Combi 30 - Flue & Air Pipe Length
15.5
30
26
22
18
14
10 10.15
6
Acceptable Operating Area
2
2 4 6 8 10 12 14 16 18 20 22 24 26 28 30
Flue Pipe Length [m]
Calculations
Air
Elbows 2 x 1m = 2m
Straights 6+2+0.15 = 8.15m
Total = 10.15m
Flue
Elbows 3 x 1m = 3m
Straights 4+6+1.5+1 = 12.5m
Total = 15.5m
Overall Flue / Air = 25.65m
11 FLUE INsTALLATION ExAMpLE KEsTON COMBI 35
Keston Combi 35 - Flue & Air Pipe Length
30
14.5
26
Sleeve 4m 22
Air
0.15m
18
4m
1.5º back to boiler
3.5m
3.5m
Bracket every
1 metre
1.5º back to boiler
2m
2m
1.5m
2.5m
14
10
15.65
6
Acceptable Operating Area
2
2 4 6 8 10 12 14 16 18 20 22 24 26 28
Flue Pipe Length [m]
Air
4 x 90º elbows
Straight lengths
Calculations
4
2
2
3.5
4
0.15
15.65
Flue
3 x 90º elbows
Straight lengths
3
2.5
1.5
3.5
4
14.5
Overall Flue / Air = 30.15m
16 Keston Combi - Installation and Servicing
12 FLUE TERMINATION pOsITION
INSTALLATION
Twin Flue Positions Flue Minimum Spacing Air Minimum Spacing
I.
J.
K.
L.
M.
N.
E.
F.
G.
H.
A.
B.
C.
D.
Below an opening (1)
Above an opening (1)
Horizontally to an opening (1)
Below gutters, soil pipes or drain pipes
Below eves
Below balcony or car port roof
From a vertical drain pipe or soil pipe
From an internal or external corner or to a boundary alongside the terminal
Above ground, roof or balcony level
From a surface or a boundary facing the terminal
From a terminal facing the terminal
From an opening in the car port into the building
Vertically from a terminal on the same wall
Horizontally from a terminal on the same wall
300 mm
300 mm
300 mm
75 mm
200 mm
200 mm
150 mm
300 mm
300 mm
600 mm
1200 mm
1200 mm
1500 mm
300 mm
12"
12"
12"
3"
8"
8"
6"
12"
12"
24"
48"
48"
60"
12"
50 mm
50 mm
50 mm
75 mm
50 mm
50 mm
50 mm
50 mm
100 mm
100 mm
1200 mm
100 mm
1500 mm
300 mm
4"
4"
48"
4"
60"
12"
2"
2"
2"
2"
2"
2"
2"
3"
(1) An opening here means an openable element, such as a openable window, or a fixed opening such as an air vent. However, in addition, the outlet should not
be nearer than 150mm (fanned draught) to an opening into the building fabric formed for the purpose of accommodating a built in element, such as a window frame.
The dimensions given in the table above may need to be increased to avoid wall staining and nuisance depending on site conditions.
boundary
J
H boundary
I
L
F
G
I
A
B
C
D, E
H
H
M
N
K
gENERAL INsTALLATIONs
All parts of the system must be constructed in accordance with BS 5440 Part 1, except where specifically mentioned in these instructions.
All pipe work must be adequately supported.
All joints other than approved push-on or plastic compression connectors must be made and sealed with solvent cement suitable for muPVC pipes and conforming to BS 6209: 1982.
Consideration must be given to Corgi/Gas Safe bulletin TB200/TB008 regarding flues in voids.
The boiler casing must always be correctly fitted to the boiler when leaving the appliance operational.
External wall faces and any internal faces of cavity walls must be good.
AIR sUppLy
The Keston Combi is a room-sealed appliance and therefore does not require purpose provided ventilation to the boiler room for combustion air.
COMpARTMENT INsTALLATION
Due to the low casing temperatures generated by the boiler, no compartment ventilation is required. However, the cupboard or compartment must not be used for storage.
Keston Combi - Installation and Servicing 17
INSTALLATION
13 INsTALLINg ThE BOILER
Installation of the boiler is straightforward but consideration must be given to access to allow flue and air pipes to be pushed through walls and ceilings. The order in which the components are installed will depend upon particular site conditions, but in general it will be easiest and most accurate to install the boiler and then build up the flue outlet and air inlet pipes to the terminal
- this is the sequence described.
14 WALL MOUNTINg TEMpLATE
The wall mounting template is located on the internal protective packaging.
Note.
The template shows the positions of the fixing holes and the position of the air and flue connections. Care MUST be taken to ensure the correct holes are drilled.
1. Tape template into the selected position. Ensure squareness by hanging a plumbline as shown.
2. Mark onto the wall the following:
a The wall mounting plate screw positions (choose one from each group).
b The position of the air and flue when exiting straight out of the wall where the boiler is mounted.
Note. Mark the centre of the hole as well as the circumference.
3. Remove the template from the wall.
18
15 pREpARINg ThE WALL
IMpORTANT.
Ensure that, during the cutting operation, masonry falling outside of the building does not cause damage or personal injury.
1. Cut the flue and air holes (preferably with 60mm core bore tool) ensuring the holes are square to the wall.
2. Drill 2 holes with a 7.5mm / 8mm masonry drill and insert the plastic plugs, provided, for the wall mounting plate.
3. Locate 2 No.14 x 50mm screws in the wall mounting plate
(one at each side, in any of the 3 holes provided at each side) and screw home.
Rear flue only
60mm diameter holes
X
Section through wall
Note. Check all of the hole positions before drilling.
Keston Combi - Installation and Servicing
INSTALLATION
16 FITTINg ThE WALL MOUNTINg pLATE 17 MOUNTINg ThE BOILER
Screw the wall mounting plate to the wall using 2 wall plugs
(previously fitted) with the 2 screws provided.
Choose one of the 2 sets of slots in left and right bank.
Ensuring that at least one of the screws is fitted into a top slot.
1. Ensure the plastic plugs are removed from both the CH and DHW connections before mounting the boiler.
2. Lift the boiler onto the wall mounting plate (refer to the
Introduction section for safe handling advice), locating it over the two tabs.
Example of fixing esp9496
Keston Combi - Installation and Servicing 19
20
INSTALLATION
18 AssEMBLy pRACTICE
Remove all plastic debris and burrs when installing air intake piping. Plastic fillings caused by cutting muPVC pipe must not be allowed to be drawn into the combustion air blower. Prevent dust entering the air intake when cutting on building sites. Blower failure which is determined to be caused by plastic filings or other debris will not be covered by guarantee.
INsTALLINg FLUE AND AIR pIpEs
Important - When installing the boiler on an existing system a new flue and air intake system MUST also be installed. You
MUsT NOT re-use existing flue or air pipework components.
• Remove the flue adaptor and air spigot from the flue pack supplied with the boiler.
• Remove boiler front panel - Frame 39.
• Remove air intake blanking plate by unscrewing 4 x M5 screws and put to one side, leaving sponge gasket in place.
•
Fix air spigot to boiler using the 4 M5 screws, see diag. below. Ensure sponge gasket is in place and not damaged.
• Insert the flue adaptor into the flue manifold on the top of the boiler and secure using the clamp provided in the packaging box, see diagram below.
•
Measure, cut and check the air and flue pipes to pass to the exit from the wall(s) or ceiling.
•
Always thoroughly deburr all pipes and most important, remove shavings from within the pipe.
• Assemble, using solvent weld cement, the pipework from the boiler connections to the exit from the first wall/ceiling,
(remount the boiler if removed). When pushing pipe through walls, ensure grit and dust is not allowed to enter the pipe.
Ensure pipes are fully engaged into sockets and solvent welded with no leaks.
•
Using the same methods drill any further holes (always covering existing pipework), cut and assemble the pipework.
• From outside, complete the two terminations - See Frame
8 Flue System and make good all holes. (Wall sealing collars are available to make good hole areas on the wall face (part number C.08.0.00.07.0).
•
support any pipes whose route could be displaced either of its own accord or by accident. Any horizontal run over 1m or vertical runs of any length must always be supported. Brackets should be placed at intervals of approximately 1m. Brackets should be loose enough on the pipe to allow thermal expansion and contraction movement.
•
Flue pipework through walls MUsT be sleeved to allow thermal expansion and contraction movement.
•
Check all connections for security and re-seal any joints using solvent cement where soundness may be in doubt.
Note. It is equally important to seal the air inlet with solvent cement as the flue outlet pipe joints.
Keston Combi - Installation and Servicing
INSTALLATION
19 FITTINg ThE FLUE sLEEVE
1. Cut hole in wall.
2. Measure wall Thickness
3. Cut sleeve length to match wall thickness & remove burrs.
4. Grout sleeve into wall with flange on external face.
5. Slide flue pipe into sleeve, checking it is free to slide.
6. Slide Flexible wall seal over flue pipe and push centre ring up to sleeve flange when cold.
7. Locate wall plate over flexible wall seal and clamp in place using the raw plug pack.
8. Affix flue terminal
9. During boiler test check that the flue end is free to expand and contract with flexible wall seal.
Flue
Terminal
Flue Pipe
Flue Sleeve Flue Sleeve Flange
Flexible
Wall
Seal
Wall
Plate
Keston Combi - Installation and Servicing 21
22
INSTALLATION
20 CONDENsATE DRAIN
47
203
Condensate
Drain
149
T his appliance is fitted with a siphonic 75mm condensate trap system that requires filling before operating the appliance for the first time or after maintenance.
All condensate pipework should conform to the following: a. Where a new or replacement boiler is being installed, access to an internal ‘gravity discharge’ termination should be one of the main factors considered in determining boiler location.
b. Plastic with push fit or solvent connections.
c. Internal plastic pipe work a minimum of 19mm ID (typically
22mm OD) d. External plastic pipe must be a minimum of 30mm ID (typically
32 OD) before it passes through the sleeved wall.
e. All horizontal pipe runs, must fall a minimum of 45mm per metre away from the Boiler.
f. External & unheated pipe work should be kept to a minimum and insulated with Class “O” waterproof pipe insulation.
g. All installations must be carried out in accordance to the relevant connection methods as shown in the “Condensate installation diagrams” & BS6798:2009 h. Pipe work must be installed so that it does not allow spillage into the dwelling in the event of a blockage (through freezing) i. All internal burrs should be removed from the pipe work and any fittings.
In order to minimise the risk of freezing during prolonged very cold spells, one of the following methods of terminating condensate drainage pipe should be adopted.
Internal Drain Connections
Wherever possible, the condensate drainage pipe should be routed to drain by gravity to a suitable internal foul water discharge point such as an internal soil and vent stack or kitchen or bathroom waste pipe etc. See Figs 1 and 2.
Condensate pump
Where gravity discharge to an internal termination is not physically possible or where very long internal pipe runs would be required to reach a suitable discharge point, a condensate pump of a specification recommended by the boiler or pump manufacturer should be used terminating into a suitable internal foul water discharge point such as an internal soil and vent stack or internal kitchen or bathroom waste pipe etc. (fig 3).
External Drain Connections
The use of an externally run condensate drainage pipe should only be considered after exhausting all internal termination options as described previously. An external system must terminate at a suitable foul water discharge point or purpose designed soak away.
If an external system is chosen then the following measures must be adopted:
The external pipe run should be kept to a minimum using the most direct and “most vertical” route possible to the discharge point, with no horizontal sections in which condensate might collect.
- For connections to an external soil/vent stack see Fig 4.
Insulation measures as described should be used.
- When a rainwater downpipe is used, an air break must be installed between the condensate drainage pipe and the downpipe to avoid reverse flow of rainwater into the boiler should the downpipe become flooded or frozen, see Fig 5.
- Where the condensate drain pipe terminates over an open foul drain or gully, the pipe should terminate below the grating level, but above water level, to minimise “wind chill” at the open end. The use of a drain cover (as used to prevent blockage by leaves) may offer further prevention from wind chill. See Fig 6.
- Where the condensate drain pipe terminates in a purpose designed soak away (see BS 6798) any above ground condensate drain pipe sections should be run and insulated as described above. See Fig 7
Unheated Internal Areas
Internal condensate drain pipes run in unheated areas, e.g. lofts basements and garages, should be treated as external pipe.
Ensure the customer is aware of the effects created by a frozen condensate and is shown where this information can be found in the user manual.
Figure 1 - Connection of Condensate Drainage Pipe to
Internal Soil & Vent Stack
Boiler with 75mm sealed condensate trap
Min Ø 19mm
Internal pipe
Boilers without 75mm sealed condensate trap must be fitted with a 75mm trap and visible air break
Minimum connection height up to 3 storeys
Figure 2 - Connection of a Condensate Drainage Pipe
Downstream of a Sink, Basin, Bath or Shower Water Trap to
Internal Soil Vent Stack
Boiler with 75mm sealed condensate trap
Min Ø 19mm
Internal pipe
Sink/basin/ bath or shower
Boilers without 75mm sealed condensate trap must be fitted with a 75mm trap and visible air break continued . . . . .
Keston Combi - Installation and Servicing
INSTALLATION
21 CONDENsATE DRAIN - CONT’D.......
Figure 3 - Connection of a Condensate Pump Typical
Method (see manufacturers detailed instructions)
Figure 4 - Connection of condensate Drainage Pipe to
External Soil & Vent Stack
Boiler with 75mm sealed condensate trap
Min Ø 19mm
Internal pipe
Visible air break
Boiler with 75mm sealed condensate trap
Min Ø 19mm
Internal pipe
Min Ø 30mm
Internal pipe
Water/weather proof insulation
Condensate pump
(Install in accordance with manufacturers instructions) Boilers without 75mm sealed condensate trap must be fitted with a 75mm trap and visible air break
Minimum connection height up to 3 storeys
Figure 5 - Connection of a Condensate Drainage Pipe to an
External Rainwater Downpipe (only combined foul/rainwater drain)
Boiler with 75mm sealed condensate trap
Min Ø 19mm
Internal pipe
Min Ø 30mm
Internal pipe
Terminated and cut at 45º
43mm 90º male/ female bend
Water/ weather proof insulation combined foul/ rain water drain
External air break
Air gap
68mm Ø PVCU
Strap on fitting
Figure 6 - Connection of Condensate Drainage Pipe
Upstream of a Sink, Basin, Bath or Shower Waste Trap to
External Drain, Gulley or Ranwater Hopper
Boiler with 75mm sealed condensate trap
Min Ø 19mm
Internal pipe
Sink, basin, bath or shower with integral overflow and 75mm trap
Visible air break at plug hole
Minimum 30mm internal pipe
Water/ weather proof insulation
45º pipe termination
Figure 7 - Connection of a Condensate Drainage Pipe to an
External Purpose Made Soak Away.
Boiler with 75mm sealed condensate trap
Min Ø 19mm
Internal pipe
Min Ø 30mm
Internal pipe
Water/Weather proof insulation
Max 3m external pipework
Boilers without 75mm sealed condensate trap must be fitted with a 75mm trap and visible air break
2 rows of three Ø12mm holes
25mm centres, 50mm from the bottom of the tube, facing away from the house
≥ 500
Limestone chippings
Keston Combi - Installation and Servicing 23
INSTALLATION
22 CONNECTIONs & FILLINg
NOTEs.
Ensure all boss blanking plugs are removed before connecting hardware. Each valve must be fitted to the correct boss as shown in the picture.
Ensure each union is fitted with fibre seals provided.
Do not subject any of the isolating valves to heat as the seals may be damaged.
Note. The domestic hot water flow rate is automatically regulated to a maximum of 12.4 l/m (2.8 gpm)
WATER CONNECTIONs Ch
1. Connect the CH flow service valve (black handle) and copper tail provided in the hardware pack to the threaded boss connection provided at the lower rear of the boiler.
2. Connect the CH rtn. valve (black handle) and copper tail.
3. If connecting the boiler to heating loads in excess of
60,000 Btu/h, connecting flow and return heating systems pipework must be sized in 28mm diameter at the point of pipe connection to the boiler tails. use 22mm x 28mm pipe adaptors as appropriate.
WATER CONNECTIONs DhW
1. Fit the DHW inlet service valve (blue handle) and copper tail to the threaded boss connection ensuring the seal provided is correctly located.
2. Fit the DHW outlet pipe tail to DHW outlet connection, ensuring the seal provided is correctly located.
3. Fit the filling loop provided between the DHW inlet valve and the CH return valve
gAs CONNECTION
IMpORTANT. The gas service cock is sealed with a non-metallic blue fibre washer, which must not be overheated when making capillary connections. Refer to Frame 1 for details of the position of the gas connection.
For additional gas supply info refer to “Gas Supply” on page 8.
FILLINg
FILLINg
IMpORTANT - when filling:
When filling, there may be a slight water leak from the air vent therefore electrical connections should be protected.
1. Ensure Filling Loop is connected
2. Ensure dust cap on auto air vent is slackened off (refer to
Frame 66).
3. Check all isolation handles on all water connections are in the open position.
4. Open handle on the filling loop, then slowly open handle
until pressure gauge reads between 1 to 1.5 bar.
5. Once pressure gauge dial reads between 1 - 1.5 bar turn the filling loop isolation valves back to the closed position.
6. Disconnect filling loop at the LH side, ensuring top hat washer is retained and screw on blanking cap.
7. Connect extended blanking cap and top hat washer to filling loop pipe.
Note. Fully open all DHW taps and ensure water is flowing freely. Once satisfied close all taps.
Handle
(Shown in closed position)
sAFETy VALVE DRAIN
The safety valve connection, located at the bottom right-hand side of the boiler, comprises a 15mm diameter stub pipe.
The Installer to provide a compression joint on the end of the stub pipe. This assists with pipe removal when servicing.
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 the electrical components and wiring.
CH Flow
DHW
Outlet
Gas
Supply
Handle
(Shown in closed position)
DHW
Inlet
CH
Return
Black
Handle
Note that all isolation handles are shown in the open postion.
Yellow
Handle
Blue
Handle
Filling
Loop
Black
Handle
Black
Handle
Safety
Drain
Valve
24 Keston Combi - Installation and Servicing
23 ELECTRICAL CONNECTIONs
INSTALLATION
Warning. This appliance MUST be earthed.
A mains supply of 230Vac ~ 50 Hz is required.
The fuse rating should be 3A. All external controls and wiring must be suitable for mains voltage.
Wiring external to the boiler MUST be in accordance with the current I.E.E. (BS.7671) Wiring Regulations and any local regulations.
Wiring should be 3 core PVC insulated cable, not less than
0.75mm
2 (24 x 0.2mm), and to BS 6500 Table 16. For IE reference should be made to the current ETCI rules for electrical installations.
Connection must be made in a way that allows complete isolation of the electrical supply such as a double pole switch having a 3mm (1/8”) contact separation in both poles. The means of isolation must be accessible to the user after installation.
24 INTERNAL WIRINg
The Keston Combi boiler comes pre-fitted with 1.8m of mains cable. This must be connected to a permanent live supply and NOT switched by thermostats/programmers.
For installers wishing to change this cable refer to Frame
26.
The Keston Combi boiler comes pre-fitted with a link wire between the room thermostat/Timer connections on the terminal strip. This creates a permanent call for heat and must be removed when adding a room thermostat/ programmer.
The terminal block cover carries two spare fuses for the main PCB.
To add thermostat/programmer:
1. Isolate the mains supply to the boiler.
2. Remove the front panel. Refer to Frame 39.
3. Swing the control box down into the servicing position.
Refer to Frame 45.
4. Route incoming cables through the grommets in bottom panel (note, grommets are ‘blind’ and will require puncturing) and secure using clamps and screws provided in hardware pack.
5. Pull off rubber terminal block cover.
6. Connect wires to terminal block, as shown below
7. Re-assemble in reverse order.
Spare PCB fuses
Keston Combi - Installation and Servicing continued . . . .
25
INSTALLATION
25 INTERNAL WIRINg.... CONT’D
Keston offer 2 kits as follows:
(see individual kits for installation instructions)
Electronic Timer (7 day) kit - 7 day electronic CH timer fits into the control box of the boiler. This can be fitted in conjunction with a room thermostat. Features English language installation help messages.
DIAGRAM A
Internal Timer or
Programmable Room Stat
L
N
ROOM
STAT/
TIMER
FROST
STAT
( OPTIONAL )
N
Room
Stat or
Prog.
Room
Stat
(1) ROOM ThERMOsTAT WITh INTERNAL BOILER TIMER OR
(2) pROgRAMMABLE ROOM ThERMOsTAT
1. Remove link wire between room stat/timer terminals.
2. Connect room stat across terminals as shown in diagram A
3. If room stat has a neutral connection, connect this to terminal
N (load) in the fused spur.
DIAGRAM B
External
Timer
L
N
ROOM
STAT/
TIMER
FROST
STAT
( OPTIONAL )
N
Stat
Optional
Frost Stat
ROOM ThERMOsTAT + TIMER
1. Remove link wire between room stat/timer terminals.
2. Connect room stat and programmer in series as shown in diagram B.
3. If room stat has a neutral connection, connect this to terminal N (load) in the fused spur.
FROsT ThERMOsTAT
If parts of the system are vulnerable to freezing or the programmer is likely to be left off during cold weather, a frost stat should be fitted in conjunction with a pipe thermostat.
1. Position the frost thermostat in a suitable position, i.e. area vulnerable to freezing.
2. Connect frost stat across terminals marked frost stat shown in diagrams A &
B.
26
DIAGRAM C
Weather Compensation Kit
L
N
ROOM
STAT/
TIMER
FROST
STAT
( OPTIONAL )
OpenTherm
Harness
Weather
Compensation
Timer
Optional
Frost Stat
WEAThER COMpENsATION KIT
The two wires from the weather compensation kit (outside sensor), must be connected into the two right hand terminals as shown in diagram C.
Keston Combi - Installation and Servicing
INSTALLATION
26 REpLACINg pRE-FITTED MAINs CABLE
If it is necessary to use an alternative mains cable to the one pre-fitted then use the following guide.
Replacement wiring should comply with notes in Frame 23.
1. Isolate the mains supply to the boiler.
2. Remove the front panel. Refer to Frame 39.
3. Swing the control box down into the service position. Refer to frame 45.
4. Remove the live, neutral and earth wires from the terminal block.
5. Loosen the cable clamp and withdraw the mains cable.
6. Route replacement cable back through the cable clamp and grommet and re-tighten to provide cord anchorage.
7. Connect the live, neutral and earth wires to the terminal strip.
When making the mains electrical connections to the boiler it is important that the wires are prepared in such a way that the earth conductor is longer than the current carrying conductors, such that if the cord anchorage should slip, the current carrying conductors become taut before the earthing conductor.
8. Swing the control box back up into the operating position and re-fit the front panel ensuring a good seal is made.
4
5
27 FITTINg ThE WEAThER COMpENsATION KIT - sUppLIED As sTANDARD
This kit provides the facility to apply outside air temperature control to the boiler water flow temperature which provides energy savings. The outside sensor provided measures outside air temperature and sends a signal to the boiler, which adjusts the maximum boiler flow temperature in response. If outside air temperature is greater than the system design temperature, the boiler flow temperature is reduced providing running cost savings. The boiler will operate in the condensing mode more frequently increasing savings.
Once the sensor is fitted it is automatically detected.
The sensor operation may be configured by adjustment of the boiler operating parameters, if necessary.
Kit Contents
A. Outside Air Sensor
A
FITTINg ThE KIT
Note. A timer should be fitted to the system so that CH will be switched off when appropriate.
Fitting the sensor
3G10011
The air sensor should be located on an external wall of the building to be heated. Fix the sensor to a north/north-east facing wall to avoid direct radiation from the sun. The air sensor should be located to avoid any heating effect from the boiler flue.
To fix the air sensor to the wall, unscrew the sensor box plastic cover and screw/plug the sensor body to the wall.
Wire a twin core 0.5mm
2 cable from the sensor to the boiler through an RH grommet located on the underside of the boiler. Cable length between sensor and boiler should be no greater than 20m. Note that this connection is safety extra low voltage. It is not necessary for the person carrying out the wiring to be approved to Part P of the Building Regulations.
Avoid running this cable alongside mains voltage cables.
4 Wiring the Weather Compensation Kit to the Keston Combi.
1. Isolate the electricity supply to the boiler.
2. Remove the boiler front panel (refer to boiler installation instructions).
3. Hinge down the control box.
4. Connect the sensor wiring into the RHS of the 4 way terminal block and secure with a cable clamp.
5. Re-assemble in reverse order.
Keston Combi - Installation and Servicing 27
INSTALLATION
28 Ch OpERATION
The On and Off time control of central heating should be controlled by a separate timer. This can be a standard unit or either of the options available from Keston Combi range.
During programmed On times the Central Heating Radiator Flow Temperature is controlled by the boiler relative to the Outside
Temperature as shown in the following diagram.
Weather Compensation Control / Room Setpoint = +20ºC
Heating slope
2.5
2.2 2.0
1.8 1.6
1.4
1.2
1.0
20 10 0 -10 -20
Outside Temperature [ºC]
-30
40
30
-40
20
100
90
80
70
60
50
The Room temperature can be adjusted using the Central Heating Temperature Control Knob on the boiler as follows.
Essentially rotating the knob clockwise increases the room temperature and rotating the knob anti-clockwise decreases the room temperature.
If the Central Heating Temperature Control Knob is rotated fully clockwise then for an Outside Temperature of 15°C a Flow
Temperature of 40°C will be provided. For an Outside Temperature of 0°C a Flow Temperature of 78°C will be provided with the relationship varying lineally in between these 2 points (line on the graph 2.5)
If the Central Heating Temperature Control Knob is in its mid position then for an Outside Temperature of 15°C a Flow
Temperature of 36°C will be provided. For an Outside Temperature of 0°C a Flow Temperature of 65°C will be provided with the relationship varying lineally in between these 2 points (line on the graph between 1.6 and 1.8)
If the Central Heating Temperature Control Knob is rotated fully anti-clockwise then for an Outside Temperature of 15°C a Flow
Temperature of 30°C will be provided. For an Outside Temperature of 0°C a Flow Temperature of 44°C will be provided with the relationship varying lineally in between these 2 points (line on the graph 1.0)
28 Keston Combi - Installation and Servicing
INSTALLATION
29 ExTERNAL ELECTRICAL CONTROLs
Wiring External to the Boiler
The fuse rating should be 3A.
Wiring external to the boiler MUST be in accordance with the current I.E.E. (BS.7671) Wiring Regulations and any local regulations.
Frost protection
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.
This is usually done at the programmer, in which case the programmer selector switches are set to OFF and all the other 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.
Note. If 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.
Programmable Room Stat
Programmable
Room
Stat
Mains In
Room Stat
L N
Use of General Live for Room Stat
Room
Stat
Optional
Frost Stat
Frost Stat
Optional
Frost Stat
Mains In
Room Stat
L N
Frost Stat
3G9990a
OpenTherm programmable Room Temperature Control
Note. These terminals MUST ONLY be connected to an
OpenTherm Controller, (such as the Keston Chronothern Room
Controller (c.17.4.21.00.0). Connecting any other device / control wiring may destroy the primary PCB.
1. Isolate the mains supply to the boiler.
2. Remove the front panel. Refer to Frame 39.
3. Swing the control box down into the servicing position. Refer to Frame 45.
4. Remove the control box cover. Refer to Frame 57, no’s 3 and 4.
5. Unclip the 3 way in-line connector containing 2 purple wires and 2 red wires.
6. Connect this 3 way connector to the 3 way connector containing 2 purple wires wired from the 4 way terminal block.
7. Connect the two wires from the OpenTherm Programmable
Room Temperature Control to the two LH connections of the terminal block as shown.
8. Re-assemble in reverse order.
Keston Combi - Installation and Servicing
5 6
7
29
30
30 WIRINg DIAgRAM
INSTALLATION
Room Stat
Main Supply
Spark Generator
Flame Sensor Electrode
Divertor V
Gas Va
- blue - black - brown - red - pink - yellow - white - yellow/green - grey - orange - violet b bk br r p y w y/g g or v
Service Connector pressure Sensor
Flow Tu
Keston Combi - Installation and Servicing
INSTALLATION
31 COMMIssIONINg AND TEsTINg
A. Electrical Installation
1. Checks to ensure electrical safety should be carried out by a competent person.
2. 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. After wiring the boiler, all grommets in the bottom panel MUST be in place to ensure that the boiler case sealing is maintained.
B. gas Installation
1. The whole of the gas installation, including the meter, should be inspected and tested for tightness and purged in accordance with the recommendations of BS. 6891.
In IE refer to IS.813:2002.
2. Purge air from the gas installation by the approved methods only.
Warning.
Whilst effecting the required gas tightness test and purging air from the gas installation, open all windows and doors, extinguish naked lights and do noT smokE.
gENERAL
Please note: The combustion for this appliance has been checked, adjusted and preset at the factory for operation on the gas type defined on the appliance data plate. No measurement of the combustion is necessary. DO NOT adjust the air/gas ratio valve.
“sERVICE REqUIRED” Function
When the boiler has been installed for more than 1 year the following message will appear on the screen:
“12 Month Service Interval Request”
Having checked:
To cancel this message move the CH Temperature Control Knob away from the maximum position. Then move the knob to the maximum position, away from the maximum position and back into the maximum position again within 3s.
- That the boiler has been installed in accordance with these instructions.
- The integrity of the flue system and the flue seals, as described in the Flue Installation section.
“Service Mode” will be shown on the screen, this will disappear after
5 mins.
“AIR VENTINg” Function
Proceed to put the boiler into operation as follows:
ChECK ThE OpERATIONAL (WORKINg) gAs
INLET pREssURE
DHW Outlet
opening hot tap to maximum flow.
Gas Supply
With the boiler operating in the maximum rate condition check that the operational
(working) gas pressure at
Black
Handle
Supply” on page 8.
Yellow
Handle
Ensure that this inlet pressure can be obtained with all other gas appliances in the property working.
Gas Pressure
Test Point
The Air Venting function should not be required for this boiler.
• The Air Venting function operates for 5 mins as follows:
• Pump On for 50s, Pump Off for 10s (repeats 5 times)
• Diverter valve in hot water position for 30s then CH position for
30s (repeats 5 times)
• The function ends automatically.
DHW Inlet
CH Return
Turn and hold the Mode Knob in the Reset position for more than 5s and then turn it to the Winter or Summer position
The boiler will display “Installer Mode”
If no faults have occurred the boiler will display “No Faults”
Blue
Handle
Black
Handle
Safety
Drain
Valve
return temperature, domestic hot water temperature, DHW flow rate and diverter valve position.
3G9927a
“Venting Boiler OFF” - “For Activation change Pre-heat Mode”
Now move the pre-heat knob and the Air Venting Function will begin, the boiler will display:
“Venting Boiler Off” - “Pump and Diverter Valve Cycling” -
Duration 5 mins” - “Reset to End”
As part of the commissioning process, the combustion of this appliance must be checked and the Benchmark Checklist completed. A flow chart to assist is provided on page 71.
ATTENTION !
IT Is A CONDITION OF ThE MANUFACTURERs WARRANTy ThAT ThE BENChMARK
COMMIssIONINg ChECKLIsT Is FULLy COMpLETED AND LEFT WITh ThE AppLIANCE
Keston Combi - Installation and Servicing 31
INSTALLATION
32 INITIAL LIghTINg
Legend
A. Pre-heat On/off
B. DHW temperature control
C. CH temperature control
D. Off/Summer/Winter/Reset Control
E. Boiler Status
F. Burner ‘on’ indicator
g. CH Flow Isolating Valve
h. Pressure Gauge
J. Gas Inlet Pressure Test Point
K. Gas Service Cock
L. DHW Inlet Valve
M. CH Return Isolating Valve
N. DHW Outlet
H
A B E F
L
C
M
D
G
N
K
J
32
1. Check that the system has been filled and that the boiler is not airlocked. Ensure the automatic air vent cap is open. Refer to
Frame 22.
Note.
It is important the burner is not operated before the system is fully vented of air. If it is necessary to operate the appliance pump to assist venting of the air this must be done with the gas service cock turned off.
2. Refit the boiler front panel. Refer to Frame 39.
3. Check that the drain cock is closed and that the CH and DHW isolating valves (M, L and G) are OPEN.
4. Check that the electrical supply is OFF.
5. Check that the boiler mode control knob (D) is off.
6. Check that the gas service cock (K) is OPEN.
7. Slacken the screw in the inlet pressure test point (J) and connect a gas pressure gauge via a flexible tube.
8. Switch the electricity supply ON and check all external controls are calling for heat.
DOMEsTIC hOT WATER
11. With the boiler firing, set the DHW Temp Control knob (B) to maximum and fully open a DHW tap.
The boiler will continue to run and the display (E) will show “Hot Water” - “Temperature XX
Efficiency”.
o C” - “High
12. Ensure that with the boiler operating the dynamic gas pressure is able to obtain maximum output. Refer to Table
2.
IMpORTANT
The gas input to the burner is regulated by the gas valve according to the air flow produced by the fan. It is NOT user-adjustable. Any interference to sealed settings on the gas valve will adversely affect operation and render our warranty void.
For additional gas supply information refer to “Gas Supply” on page 8
13. Turn off the DHW tap.
CENTRAL hEATINg
9. Set the CH temp control (C) to max and turn the mode control knob (D) to , ensure the timer/room stat are on. The boiler control will now go through its ignition sequence until the burner is established.
10. If the boiler does not light the following messages will be displayed in rotation “Ignition Lockout” - “1 Check other gas appliances” - “2 Reset boiler” - “3 Contact
installer”. After 5 attempts the boiler will lock out and carry on displaying the messages. Reset the boiler (refer to Frame
40B). The boiler will repeat its ignition sequence. If reset occurs 5 times within 15 minutes then “Too many resets” will be shown. If power is removed this will be reset.
When the burner is established the BLUE ‘Burner On’ neon
(F) will be illuminated, the LCD will display “Central Heating” and “Radiator Temp XX o C”.
Note. The temperature displayed “XXºC” is that measured at that moment, not the set temperature.
Note. The boiler incorporates a fan overrun cycle which MUST NOT be prematurely interrupted by isolation of the mains electricity supply.
continued. . . . .
Keston Combi - Installation and Servicing
INSTALLATION
33 INITIAL LIghTINg . . . . CONT’D
ThE DIspLAy
The user control has one neon and one display to inform the user about the status. The display will show the status of the boiler.
The neon will show the status of the flame. If no flame is detected the neon is off. When the flame is detected the neon will be lit permanently.
The display scrolls through a maximum of 3 messages under any operational condition as shown below.
Notes: Boiler frost protection - boiler fires if temperature is below 5º C.
The temperatures shown below are for illustration purposes only. The measured temperatures will be shown on the boiler.
DIspLAy FUNCTIONs IN NORMAL OpERATION
NORMAL OPERATION MESSAGE 1
Mode knob in standby position and no heat demand
Mode knob in summer position and no heat demand
Mode knob in winter position and no heat demand
Domestic hot water operation
Standby mode
Summer mode
Winter mode
Hot water
MESSAGE 2
For hot water turn mode knob clockwise
For central heating turn mode knob clockwise
Timer or room stat off
Temperature 64ºC
MESSAGE 3
For central heating turn mode knob clockwise twice
High efficiency
Central heating operation
Pre-heat operation
Boiler frost protection
Pump overrun
Fan post-purge
Central heating
Pre heat
Boiler frost protection
Pump overrun
Fan post-purge
Radiator Temp 80ºC
Temperature 59ºC
Temperature 5ºC
High efficiency
High efficiency
High efficiency
Note. High efficiency will not be shown for central heating operation if the central heating flow temperature knob is set to greater than 73ºC.
DIspLAy FUNCTIONs - sETTINgs ChANgED
NORMAL OPERATION
Pre-heat knob moved to off position
MESSAGE 1
Pre heat off
Pre-heat knob moved to on position
DHW temperature knob moved
CH temperature knob moved
Pre heat on
64ºC DHW temp
80ºC CH temp
Mode knob moved to standby position
Mode knob moved to summer position
Mode knob moved to winter position
Mode knob moved to reset position
Standby mode
Summer mode
Winter mode
Reset
MESSAGE 2
Hot water temperature 64ºC
Maximum radiator temperature 80ºC
Central heating off
Central heating off
Central heating on
MESSAGE 3
May not be achieved for high flow rates in winter
Hot water off
Hot water on
Hot water on
Keston Combi - Installation and Servicing 33
INSTALLATION
34 INITIAL LIghTINg . . . . CONT’D
INsTALLER MODE
Installer Mode is entered as follows:
1. Turn the DHW temperature control knob full anti-clockwise.
2. Turn the CH flow temperature control knob full anti-clockwise.
3. Turn and hold the mode knob in the reset position for more than 5 secs and then turn it to the Winter or Summer position.
The boiler will display “Installer mode”.
If no faults have occurred the boiler will display “no faults”.
If any faults have occurred a list of faults up to a maximum of 10 including the type of fault and how long ago it occurred will be shown in the following format.
MESSAGE 1
LIST OF FAULTS
Fault 1 (latest fault)
Fault 2
Fault 3
MESSAGE 2
Low water pressure
No water flow lockout
Overheat lockout
The boiler will then display the current values of flow temperature, return temperature, domestic hot water temperature, DHW flow rate and diverter valve position in the following format:
MESSAGE 1
CURRENT VALUES
Flow temp 80ºC
Return temp 60ºC
DHW temp 64ºC
DHW flow rate 8 l/min
Diverter valve DHW position
MESSAGE 3
2 days ago
78 days ago
384 days ago
Note.
If you would like to hold one of the values on the display to watch its behaviour then turn the reset knob to the reset position while it is displayed and hold it there.
Finally the display will operate in one of two modes. If there is a fault then more extensive corrective actions will be shown than are usually displayed for the end user. If there is not a fault then the information displayed for current operating states will also be more extensive than is usually displayed for the end-user (pre-purge, ignition and post purge for example).
Installer mode automatically ends after 10 mins or by moving the mode knob to the standby position.
35 REsET pROCEDURE
To reset boiler, turn the mode control knob (D) to reset position and immediately turn knob back to required setting. The boiler will repeat the ignition sequence if a heat demand is present.
34
A B E
Legend
A. Pre-heat On/off
B. DHW temperature control
C. CH temperature control
F C D
D. Off/Summer/Winter/Reset Control
E. Boiler Status
F. Burner ‘on’ indicator
Keston Combi - Installation and Servicing
INSTALLATION
36 gENERAL ChECKs
Make the following checks for correct operation in:
DOMEsTIC hOT WATER (DhW) MODE
1. Fully open all DHW taps in turn and ensure that water flows freely and that the mode knob is either in summer or winter position. The boiler will display
“Hot Water” - “Temperature XX o
Efficiency”
C” - “High
where the temperature shown is the current Domestic Hot
Water temperature.
When the burner is lit the light above the display will be on.
2. Close all taps except the furthest one from the boiler and check that the boiler is firing at maximum rate.
This is factory set to give a DHW temperature rise of approximately 35
“operation”.
o C at the flow rate stated on page 6 under
3. Reduce the DHW draw-off rate to about 3 l/min (0.7gpm) and check that the boiler modulates to deliver DHW at approximately 64 o C (with the DHW temperature control knob set to maximum).
4. Close the DHW tap and check that the main burner extinguishes. The pump should overrun for 60 seconds during which the boiler will display “Pump overrun”. The fan will then continue to run for a further 3 minutes during which the boiler will display “Fan Post Purge” after which the boiler will display one of the following “Standby mode”
- “Summer mode” - “Winter Mode” depending on the position of the mode knob.
Note. On systems in excess of 2 bar inlet pressure a water pressure governor may be required to prevent water noise.
Ch & DhW MODE
1. Ensure the CH controls are calling for heat and that the boiler mode knob is in the winter position and the CH flow temperature control knob is in the maximum position. The
Boiler will display
“Central Heating” - “Radiator Temp XXC”
where the temperature shown is the current flow temperature.
When the burner is lit the light above the display will be on.
2. Fully open the DHW tap and check that hot water is delivered.
The boiler will display “Hot water” - Temperature XX
- High Efficiency” o C”
3. Gas Rate
Check the boiler gas rate when the boiler is at full DHW output. Check at the gas meter, with no other appliance in use. Refer to Tables 2 and 3 for gas rates.
4. Close the DHW tap. The burner should remain on and the boiler will display “Central heating” - “Radiator temp
XXC”.
5. Set the central heating external controls to off. The burner will go off and the fan and pump continue to run for 4 minutes.
The boiler will display “Pump overrun” after which the boiler will display one of the following: “Standby mode”
- “Summer mode” - “Winter mode” depending on the position of the mode knob.
6. Check the correct operation of the timer (if fitted) and all other system controls. Operate each control separately and check that the main burner responds.
Note. The temperature displayed “XXºC” is that measured at that moment, not the set temperature.
WATER CIRCULATION sysTEM
1. With the system COLD, check that the initial pressure is correct to the system design requirements.
For pre-pressurised systems, this should be 1.0 bar.
2. With the system HOT, examine all water connections for soundness. The system pressure will increase with temperature rise but should not exceed 2.5 bar.
3. With the system still hot, turn off the gas, water and electricity supplies to the boiler and drain down to complete the flushing process.
Note: A flushing solution should be used during the flushing procedure. Flushing solutions: Fernox
Superfloc, Sentinel X300 (new systems) or X400
(existing systems). Refer to Frame 5.
4. Refill and vent the system, add inhibitor (see Frame
5), clear all air locks and again check for water soundness.
5. Reset the system initial pressure to the design requirement.
6. Balance the system. Refer to Frame 4.
7. Check the condensate drain for leaks and check that it is discharging correctly.
Keston Combi - Installation and Servicing
8. Finally, set the controls to the User’s requirements.
Notes.
1. If the pump has not operated in the last 24 hours it will run briefly to prevent seizure
2. If the diverter valve has not operated in the last 24 hours it will be operated briefly to prevent seizure. These two operations will not occur at the same time.
WATER TEMpERATUREs
Temperatures can be selected using the CH and DHW thermostats.
Knob setting
Max
Min
Ch Flow Temp DhW Outlet Temp o C ( o F)
80 (176)
45 (113) o C ( o F)
64 (147)
40 (104)
35
36
INSTALLATION
37 hANDINg OVER
After completing the installation and commissioning of the system the installer should hand over to the householder by the following actions:
1. Make the householder aware that the user instructions are located in the pocket in the drop down door and explain his/her responsibilities under the relevant national regulations.
2. Explain and demonstrate the lighting and shutting down procedures.
3. 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 the household requirements of both heating and hot water consumption.
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.
4. Explain the function and the use of the boiler heating and domestic hot water controls.
Explain that due to system variations and seasonal temperature fluctuations DHW flow rates/temperature rise will vary, requiring adjustment at the draw off tap. It is therefore necessary to draw the users attention to the section in the Users Instructions titled “Control of Water
Temperature” and the following statement:
“Additionally, the temperature can be controlled by the user via the draw-off tap: the lower the rate the
higher the temperature, and vice versa”.
5. Explain the function of the boiler fault mode.
Emphasise that if a fault is indicated, the boiler should be turned off and a Gas Safe Registered Engineer consulted.
In IE contact a Registered Gas Installer (RGII).
6. Explain and demonstrate the function of time and temperature controls, radiator valves etc., for the economic use of the system.
7. If a timer is fitted draw attention to the timer Users
Instructions and hand them to the householder.
8. Loss of system water pressure
Explain that the dial underneath the boiler indicates the central heating system pressure and that if the normal COLD pressure of the system is seen to decrease over a period of time then a water leak is indicated. Explain the re-pressurising procedure and if unable to re-pressurise or if the pressure continues to drop a registered local heating installer should be consulted.
9. Explain boiler reset procedure (refer to Frame 35).
10. After installation and commissioning please complete the
11. A comprehensive service should be carried out ANNUALLY.
Stress the importance of regular servicing by a Gas Safe
Registered Engineer. In IE servicing work must be carried out by a Registered Gas Installer (RGII).
12. Inform the householder of the guarantee form and the requirement to register it to receive the full benefit of the warranty.
Commissioning Checklist before handover to the customer. For IE, its is necessary to complete a “Declaration of Conformity” to indicate compliance to I.S.
813:2002.
IMpORTANT
Keston Combi - Installation and Servicing
SERVICING
38 sERVICINg sChEDULE
For the very latest copy of literature for specification & maintenance practices, visit our website www.keston.co.uk, where you will be able to download the relevant information.
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.
Combustion testing must be carried out by a competent person using a combustion analyser conforming to Bs7927.
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 Gas Safe Registered Engineer. In IE service work must be carried out by a Registered Gas Installer (RGII).
INspECTION
1. Light the boiler and carry out a pre-service check, noting any operational faults.
2. Check the flue terminal (and terminal guard if fitted) is undamaged and clear of any obstruction.
gENERAL
Please note: During routine servicing, and after any maintenance or change of part of the combustion circuit, the following must be checked:
3. Check all water and gas joints for signs of leakage. Remake any suspect joints ensuring a gas tightness check is carried out if applicable and the water system is correctly refilled, vented and re-pressurised.
CLEANINg pROCEDURE
Note. In order to carry out either servicing or replacement of components the boiler front panel must be removed. Refer to
Frame 39.
1. Clean the main burner. Refer to frame 41.
2. Clean the heat exchanger & condensate trap/siphon. Refer to
Frames 41 & 42.
- The integrity of the flue system and the flue seals,
- The integrity of the boiler combustion circuit and the relevant seals
- The operational (working) gas inlet pressure at maximum rate.
- The gas rate
- The combustion performance.
COMpETENCE TO CARRy OUT ThE ChECK
OF COMBUsTION pERFORMANCE
Please note: BS 6798:2009 Specification for installation and maintenance of gas-fired boilers of rated input not exceeding 70kW net advises that:
3. Check the main injector for blockage or damage. Refer to Frame
40.
4. Check that the flue terminal is unobstructed and that the flue system is sealed correctly.
- The person carrying out a combustion measurement should have been assessed as competent in the use of a flue gas analyser and the interpretation of the results.
ALSO IF THE DHW FLOW RATE IS IN QUESTION :-
5. Check the DHW filter for blockage. Refer to Frame 70.
The cleaning procedures are covered more fully in Frames 40-45 and
MUST be carried out in sequence.
- The flue gas analyser used should be one meeting the requirements of BS7927 or BS-EN50379-3 and be calibrated in accordance with the analyser manufacturers requirements, and
IMpORTANT.
6. After completing the servicing or exchange of components always test for gas tightness.
7. When work is complete the front panel MUST be correctly refitted, ensuring that a good seal is made.
- Competence can be demonstrated by satisfactory completion of the CPA1 ACS assessment, which covers the use of electronic portable combustion gas analysers in accordance with BS7967, Parts 1 to 4.
do noT oPEraTE the boiler if the front panel is not fitted.
8. If, for any reason, the condensate trap/siphon has been removed ensure the trap is refilled with water before reassembling.
9. Check the gas consumption.
10. Check combustion by connecting the flue gas analyser to the flue gas sampling point as shown in the diagram and measure CO &
CO
2
.
If the CO/CO
2 ratio is greater than 0.004 AND the integrity of the complete flue system and combustion circuit seals have been verified and the inlet gas pressure (and gas rate) have been verified, then contact Keston.
11. Complete the service section in the Benchmark Commissioning
Checklist.
Keston Combi - Installation and Servicing 37
SERVICING
39 BOILER FRONT pANEL REMOVAL / REpLACEMENT
REMOVAL
1. Loosen the two screws retaining the front panel.
2. Pull the two spring clips down to disengage and pull panel forward and upward and remove.
REpLACEMENT
3. Hook the panel onto the top retaining clips.
4. Push the panel until the 2 bottom spring clips engage ensuring the 4 control knobs line up with the holes in the front panel.
5. Re-tighten the two retaining screws.
3
1
2 view from bottom of boiler
38 view from top of boiler
40 FAN AND VENTURI AssEMBLy REMOVAL AND CLEANINg
1. Disconnect the electrical leads from the fan.
2. Undo the gas pipe union connection to the injector housing.
3. Remove the extended nut on the fan mounting bracket.
4. Lift off fan and venturi assembly.
5. Inspect the injector for blockage or damage.
6. Inspect fan outlet sealing gasket and replace if necessary.
3
5
Injector
2
1
Keston Combi - Installation and Servicing
SERVICING
41 BURNER REMOVAL AND CLEANINg
1. Ensure the sump is fully drained
2. Undo the two screws and remove the sump cover retaining the lower flue manifold.
3. Lift the manifold to clear the bottom sealing gasket and remove manifold.
4. Remove the 2 burner front fixing screws and loosen the 2 rear extended nuts by at least ten turns.
5. Lift off the burner from the combustion chamber. To facilitate the removal angle the burner as shown.
IMpORTANT
The burner head is a ceramic plaque construction. Care must be taken to ensure that the burner is not placed down upon
its face as this may cause damage to the ceramic.
6. Brush off any deposits that may be on the ceramic with a
SOFT brush.
7. Inspect the sealing gasket around the burner for any signs of damage. Replace as necessary.
2
5
3
4
4
42 CLEANINg ThE CONDENsATE TRAp/sIphON
1. Pull off the rubber pipe at the sump drain.
2. Disconnect the condensate drain pipe.
3. Turn the siphon clockwise to disengage and lift to remove.
Note. Keep siphon upright when removing
4. Clean siphon with water.
5. Re-assemble in reverse order.
B When re-assembling ensure the trap is full of water.
1
2
Keston Combi - Installation and Servicing
3G9690
39
40
SERVICING
43 CLEANINg ThE hEAT ExChANgER
note: Ensure the condensate trap/siphon
is fully drained before cleaning. Refer to
Frame 61.
1. Remove ignition and flame detection electrodes. Refer to Frames 51 & 52.
2. It is advisable to replace the sump cover prior to the water flush process.
3. Thoroughly flush the heat exchanger by pouring water into the top of the combustion chamber ensuring the full top area is covered.
4. Remove the sump cover and clean loose deposits from the sump.
5. Inspect the ignition and detection electrodes. Ensure that they are clean and in good condition - replace if necessary.
6. Re-fit the ignition and flame detection electrodes, ensuring that both earth tabs are fitted to ignition electrode.
7. Check that the ignition and detection gaps are correct. Refer to Frames 51 & 52.
1
Ignition Electrode
3
Flame Detection
44 REAssEMBLy
Reassemble the boiler in the following order:
1. Ensure that the condensate trap/siphon is full of water.
2. Refit the burner ensuring the sealing gasket is correctly positioned and free from damage (tighten the 4 fixing screws in the sequence shown below).
3. Refit the fan / venturi assembly ensuring the retaining tabs are correctly positioned and the sealing gasket is correctly positioned and free from damage.
4. Reconnect the fan electrical leads.
5. Remove the sump cover and refit the lower flue manifold as shown.
6. Refit the sump cover.
7. Refit the boiler front panel.
IMpORTANT. Ensure that the boiler front panel is correctly fitted and that a good seal is made.
8. Swing the control box back into its working position and secure.
9. Turn on the gas supply at the gas service cock.
10. Reconnect the electrical supply.
4
2
5
1
3
Keston Combi - Installation and Servicing
SERVICING
45 REpLACEMENT OF COMpONENTs
gENERAL
When replacing ANy component
1. Isolate the electricity supply.
2. Turn off the gas supply.
3. Remove the boiler front panel. Refer to Frame 39.
4. Release the retaining clip and swing the control box down into its servicing position.
After replacing ANY component check operation of the boiler, including gas tightness, gas rate and combustion test.
IMpORTANT.
When work is complete, the front panel must be correctly refitted - ensuring that a good seal is made.
Notes.
1. In order to assist fault finding, the control panel has an LED diagnostic display. The key to boiler fault
conditions is shown in Frame 75.
2. In order to replace components in Frames 61-72 it is necessary to drain the boiler. Refer to Frame 60.
4
ThE BOILER MUsT NOT BE OpERATED WIThOUT ThE FRONT pANEL FITTED
46 FAN REpLACEMENT
1. Refer to Frame 45.
2. Disconnect the electrical leads from the fan.
3. Undo the gas pipe union connection to the injector housing.
4. Remove the extended nut retaining the fan mounting bracket.
5. Lift and remove the fan and venturi assembly.
6. Remove the screw and twist venturi anticlockwise to remove venturi assembly, noting the orientation of the venturi in relation to the fan body.
7. Transfer the venturi assembly to the new fan, replacing the ‘o’ ring if evidence of damage or deterioration is visible.
8. Fit the new fan / venturi assembly ensuring the retaining tabs are correctly positioned and the fan outlet sealing gasket is correctly positioned and free from damage. Refit the extended nut.
9. Reassemble the boiler in reverse order, taking care not to overtighten the screw on the fan mounting bracket.
10. Check the operation of the boiler. Refer to
Frame 36.
Keston Combi - Installation and Servicing
4
8
3
6
Retaining Tabs
2
41
SERVICING
47 BURNER INJECTOR REpLACEMENT
4 1. Refer to Frame 45.
2. Disconnect the electrical leads from the fan.
3. Undo the gas pipe union connection to the injector housing.
4. Loosen the screw retaining the fan mounting bracket.
5. Lift and remove the fan and venturi assembly.
6. Remove the 2 injector housing screws.
7. Withdraw the injector housing.
8. Fit the new injector housing complete with injector.
9. Reassemble in reverse order, ensuring that the new gas seal supplied is located correctly in the injector housing.
10. Check operation of the boiler. Refer to Frame 36.
6
3
2
42
48 BURNER REpLACEMENT
1. See Frame 39.
2. Refer to Frame 45.
3. Disconnect 2 flag terminals from the flue thermostat.
4. Undo the two screws and remove the sump cover.
5. Lift the manifold to clear the bottom sealing gasket and remove manifold.
6. Remove the 2 front fixing screws and loosen the 2 rear extended nuts.
7. Lift off the burner from the combustion chamber. To facilitate the removal angle the burner as shown.
8. Fit the new burner, replacing any damaged or deteriorating sealing gasket.
9. Reassemble in reverse order. Refer to Frame 44.
10. Check the operation of the boiler. Refer to Frame 36.
4
7
5
6
4
6
Keston Combi - Installation and Servicing
SERVICING
49 RETURN ThERMIsTOR RENEWAL
1. Refer to Frame 44.
2. Unclip the return thermistor from the return pipe and withdraw it from the boiler.
3. Disconnect the electrical lead from the thermistor.
4. Reconnect the electrical lead to the new thermistor and reassemble in reverse order, ensuring that the thermistor is securely fitted to the pipe on the thermistor locator tabs as shown.
5. Check the operation of the boiler. Refer to Frames 29-35.
5
Thermistor Locator Tab
(with thermistor fitted)
3
50 FLUE ThERMOsTAT REpLACEMENT
1. Refer to Frame 45.
2. Undo the two screws and remove the sump cover plate.
3. Disconnect the two flag terminals from the flue thermostat.
4. Lift the manifold to clear the bottom
.
sealing gasket and remove manifold.
5. Unscrew the two M3.5 screws that connect the thermostat to the manifold.
6. Replace thermostat with new part and then refit the two screws, remembering to fit rubber gasket and sealing clamp.
Flue Thermostat
Keston Combi - Installation and Servicing 43
44
SERVICING
51 IgNITION ELECTRODE REpLACEMENT
1. Refer to Frame 45.
2. Remove the burner. Refer to Frame 48.
3. Unplug the ignition lead from the electrode.
4. Remove the earth lead from the ignition electrode.
5. Remove the 2 screws holding the ignition electrode to the combustion chamber.
6. Remove the electrode.
7. Fit the new ignition electrode, using the new gasket supplied. Check dimensions as shown.
8. Reassemble in reverse order.
9. Check the operation of the boiler. Refer to
Frame 36.
Ignition Electrode
Spark Gap
3.5mm
Str aig ht ed ge
3mm
52 FLAME DETECTION ELECTRODE REpLACEMENT
1. Refer to Frame 45.
2. Remove the burner. Refer to Frame 48.
3. Unplug the flame detection lead from the electrode.
4. Remove the 2 screws retaining the detection electrode.
5. Remove the electrode.
6. Fit the new flame detection electrode, using the new gasket supplied.
7. Reassemble in reverse order.
8. Check the operation of the boiler. Refer to
Frame 36.
Str aig ht ed ge
Flame Detection Electrode
12.5mm
Keston Combi - Installation and Servicing
SERVICING
53 spARK gENERATOR REpLACEMENT
1. Refer to Frame 45.
2. Disconnect the leads from the spark generator.
3. Remove the M5 screws securing the spark generator to the boiler chassis.
4. Fit the new spark generator and reassemble in reverse order ensuring the two earth leads are correctly replaced.
5. Check operation of the boiler. Refer to Frame 36.
2
Spark Generator
4 3
2
3
54 gAs CONTROL VALVE REpLACEMENT
1. Refer to Frame 45.
2. Unplug the electrical plug connection from the gas control valve and disconnect the earth wire.
3. Undo the union nut on the outlet of the gas control valve.
4. Undo the gas inlet pipe union at the inlet to the gas control valve.
5. Loosen the back nut retaining the valve to the bracket and withdraw the valve forwards.
6. Fit the new gas control valve ensuring the two sealing washers are in place and reconnect gas and electrical connections.
7. Check operation of the boiler. Refer to Frame
36.
4
2
Keston Combi - Installation and Servicing
3
5
45
SERVICING
55 DIVERTER VALVE ACTUATOR REpLACEMENT
1. Refer to Frame 45.
2. Remove the electrical plug.
3. Using a suitable tool pull out the retaining clip and lift the diverter head from the brass body.
4. Fit new actuator head and reassemble in reverse order.
6. Check operation of the boiler. Refer to
Frame 36.
Diverter Valve Actuator
46
Retaining Clip
56 CONDENsATE TRAp/sIphON REpLACEMENT
1. Refer to Frame 45.
2. Pull off the rubber pipe at the sump drain.
3. Disconnect the condensate drain pipe.
4. Turn the siphon clockwise to disengage and lift to remove.
Note. Keep siphon upright when removing
5. Clean siphon with water.
6. Re-assemble in reverse order.
7. When re-assembling ensure the trap is full of water.
8. Check operation of the boiler. Refer to Frame 36.
3
2
Siphon 3G9690
Keston Combi - Installation and Servicing
SERVICING
57 MAIN pCB REpLACEMENT
Note. Fit the earth strap provided with the PCB to your wrist and secure to a suitable earth on the boiler chassis.
1. Refer to Frame 45.
2. Note the control knob positions.
3. Remove the 2 screws retaining the control box cover.
4. Carefully lift the 4 retaining clips and remove control box cover.
5. Unplug all lead connections to the PCB including the ribbon cable (to facilitate ribbon cable removal, ease side clips apart and pull upwards), also where applicable, push the small plastic clip with an electrical screwdriver to facilitate plug removal.
6. Spring out the two side retaining clips and pull the PCB upwards to clear the 4 corner retaining posts.
7. Take the new Primary PCB and attach the appropriate Boiler
Chip Card (BCC).
Note. Ensure the correct orientation of BCC by placing
“TOP” side up as shown.
8. Re-connect all plug connections.
9. Reassemble in reverse order.
10. Turn power back on to the boiler, after a few moments the display will start alternating between “c” and “0”. Turn the reset knob fully clockwise and when the display shows “ - ” turn the knob fully anti-clockwise IMMEDIATELY.
Finally move the knob into the required position (Standby,
Summer or Winter).
11. Check operation of the boiler. Refer to Frame 36.
4
5
Plastic
Clip
Ribbon Cable Connection
5
3
Keston Combi - Installation and Servicing
6
7
47
SERVICING
58 UsER CONTROL pCB REpLACEMENT
Note. Fit the earth strap provided with the PCB to your wrist and a suitable earth on the boiler chassis.
1. Refer to Frame 45.
2. Remove the main PCB, refer to Frame 57.
3. Unclip the PCB and lift to clear the mounting posts.
4. Fit the new PCB ensuring the 4 potentiometer spindles line up with the control knobs which must be in a vertical position.
5. Reassemble in reverse order.
6. Check operation of the boiler. Refer to Frame
36.
4
PCB
3
Potentiometer spindle
Control Knobs (to be in vertical position)
48
59 DhW FLOW TURBINE sENsOR REpLACEMENT
1. Refer to Frame 45.
2. Remove condensate trap/siphon. Refer to Frame 56.
3. Lift off the flow turbine sensor plastic retaining clip.
4. Unplug the electrical connection and transfer to new turbine sensor.
5. Reassemble in reverse order.
6. Check operation of the boiler. Refer to
Frame 36.
4
3
Keston Combi - Installation and Servicing
SERVICING
60 DRAININg ThE BOILER
CENTRAL hEATINg CIRCUIT
1. Refer to Frame 45.
2. Close all the CH water isolating valves on the boiler inlet.
3. To drain the primary heat exchanger circuit: Open the drain valve and attach a length of hose to the CH drain point.
4. After replacing any component on the boiler, remove the hose, close the drain valve and open all system isolating valves (re-pressurise as appropriate by re-connecting the filling loop, refer to Frame 22) before proceeding to check operation of the boiler.
5. Disconnect filling loop. Refer to Frame 22.
6. Check operation of the boiler. Refer to Frames 36.
DOMEsTIC hOT WATER CIRCUIT
1. Refer to Frame 45.
2. Close all the DHW water isolating valves on the boiler inlet.
3. To drain the domestic hot water circuit: As there is no direct drain for the domestic hot water circuit, depending on the location of the boiler, opening the lowest hot water tap may drain this circuit. However it must be noted that some residual water will be experienced during replacement of components.
4. After replacing any component on the boiler, close tap, close the drain valve and open all system isolating valves (repressurise as appropriate by re-connecting the filling loop, refer to Frame 22) before proceeding to check operation of the boiler.
5. Disconnect filling loop. Refer to Frame 22.
6. Check operation of the boiler. Refer to Frame 36.
61 pREssURE gAUgE RENEWAL
1. Refer to Frame 45.
2. Drain the heating system. Refer to Frame
65.
3. Unscrew the pressure gauge and discard.
4. Fit new pressure gauge, using suitable jointing compound.
5. Refill the boiler. Refer to Frame 22.
6. Check operation of the boiler. Refer to
Frame 36.
Keston Combi - Installation and Servicing
3G9690
3G9690
3G9690
49
SERVICING
62 sAFETy RELIEF VALVE RENEWAL
9
1. Refer to Frame 45.
2. Drain the boiler. Refer to Frame 60.
3. Remove the condensate trap/siphon. Refer to
Frame 56.
4. Remove expansion vessel. Refer to Frame 73.
5. Disconnect the electrical connection from the return thermistor.
6. Disconnect the 22mm pipe connection at the rear of the pump outlet.
7. Pull off the clip retaining the pipe to the heat exchanger swing the pipe to clear the pump and remove pipe.
8. Undo the safety valve union connection.
9. Withdraw the clip securing the safety valve.
10. Lift safety valve from boiler.
11. Fit the new safety valve and reassemble in reverse order ensuring the new ‘o’ ring is fitted to the top of the return pipe.
12. Refill boiler. Refer to Frame 22. Check operation of boiler. Refer to Frames 36.
10
7
5
8
6
63 pUMp AUTOMATIC AIR VENT REpLACEMENT
1. Refer to Frame 45.
2. Drain the boiler. Refer to frame 60.
3. Remove the expansion vessel. Refer to Frame 73.
4. Firstly, increase access area by disconnecting the
22mm pipe connection at top of pump chamber and bottom of heat exchanger and remove pipe Refer to
Frame 62 (no’s 5,6 & 7).
5. The automatic air vent head is retained in the pump body with a bayonet connection. The air vent head and float assembly is removed by turning the head anticlockwise (viewed from above) and pulling upwards.
6. Reassembly is the reverse of the above. Ensure the air vent head ‘o’ ring seal is in place when refitting and the new ‘o’ ring is fitted to the return pipe top connection.
7. Ensure the air vent cap is loose.
8. Refill the boiler. Refer to Frame 22. Check for leaks around the new air vent joint.
9. Check the operation of the boiler. Refer to Frame 36.
50
5
Keston Combi - Installation and Servicing
SERVICING
64 DhW FLOW TURBINE CARTRIDgE REpLACEMENT
5 1. Refer to Frame 45.
2. Drain the boiler. Refer to Frame 60.
3. Remove condensate trap/siphon. Refer to
Frame 56.
4. Remove the DHW flow turbine sensor. Refer to
Frame 59.
5. Unscrew the top connection to access the internal part.
6. Fit the new turbine cartridge.
7. Refit the turbine flow sensor
8. Reassemble in reverse order.
9. Refill the boiler. Refer to Frame 22.
10. Check operation of the boiler. Refer to
Frames 36.
4
7
65 DIVERTER VALVE INTERNAL CARTRIDgE REpLACEMENT
FRONT CARTRIDgE REpLACEMENT
1. Refer to Frame 45.
2. Drain the boiler. Refer to Frame 65.
3. Remove the diverter valve head. Refer to Frame 55.
4. Unscrew the top connection to access the internal cartridge.
5. Fit the new valve mechanism ensuring the correct fit of the pin.
6. Reassemble in reverse order.
7. Refill the boiler. Refer to Frame 22.
8. Check operation of the boiler. Refer to
Frame 36.
REAR CARTRIDgE REpLACEMENT
1. Refer to Frame 45.
2. Drain the boiler. Refer to Frame 60.
3. Remove the diverter valve head. Refer to Frame 55.
4. Remove the flow pipe. Refer to Frame 22 no. 12.
5. Disconnect the CH flow pipe and DHW outlet pipe union connections underneath the boiler. Refer to Frame 60.
6. Remove the plate heat exchanger LH fixing screw. Refer to Frame 66.
7. Remove the screw retaining the brass block to the bottom of the boiler casing and lift the brass block clear of the boiler.
8. Unscrew the rear cartridge connection.
9. Fit the new valve mechanism ensuring the correct fit of the pin.
10. Reassemble in reverse order.
11. Refill the boiler. Refer to Frame 22.
12. Check operation of the boiler. Refer to
Frame 36.
FRONT CARTRIDgE REAR CARTRIDgE
3
4
9 8
Keston Combi - Installation and Servicing 51
SERVICING
66 DhW pLATE hEAT ExChANgER REpLACEMENT
1. Refer to Frame 45.
2. Drain the boiler. Refer to Frame 60.
3. Remove condensate trap/siphon. Refer to Frame 56.
4. Remove the diverter valve actuator. Refer to Frame 55.
5. Remove the 2 allen screws securing the plate heat exchanger to the brass housings.
6. Manoeuvre the plate heat exchanger out of the top LH or centre of the controls area.
7. Fit the new plate heat exchanger, using the new o-rings supplied.
Note. The mounting pins are offset so the correct position can be defined from the location of the holes on the brass mounting.
8. Reassemble in reverse order.
9. Refill the boiler. Refer to Frame 22.
10. Check operation of the boiler. Refer to Frame 36.
5
52
67 pUMp hEAD REpLACEMENT
1. Refer to Frame 45.
2. Drain the boiler. Refer to Frame 60.
3. Disconnect the electrical plug from the pump.
4. Remove the 4 Allen screws retaining the pump head.
5. Remove the pump head.
6. Fit the new pump head.
7. Reassemble in reverse order.
8. Refill the boiler. Refer to Frame 22.
9. Check operation of the boiler. Refer to
Frame 36.
4
3
Keston Combi - Installation and Servicing
SERVICING
68 Ch WATER pREssURE sENsOR REpLACEMENT
1. Refer to Frame 45.
2. Drain the boiler. Refer to Frame 60.
3. Remove condensate trap/siphon. Refer to
Frame 56.
4. Using a suitable tool pull out the retaining clip.
5. Pull the pressure sensor upwards to remove.
6. Unplug the electrical connection and transfer to the new pressure sensor.
7. Push the new pressure sensor onto the rear pump housing and fit retaining clip.
8. Reassemble in reverse order.
9. Refill the boiler. Refer to Frame 22.
10. Check Operation of the boiler. Refer to Frame
36.
6
4 5
69 DhW FILTER CLEANINg / REpLACEMENT
1. Refer to Frame 45.
2. Isolate the mains cold water supply to the boiler.
3. Drain the boiler DHW circuit. Refer to
Frame 60.
4. Remove the DHW flow turbine cartridge.
Refer to Frame 64.
5. Unscrew the flow regulator housing.
6. Remove the filter.
7. Clean or replace filter as necessary.
8. Reassemble in reverse order.
9. Refill the boiler. Refer to Frame 22.
10. Check Operation of the boiler. Refer to
Frame 36.
5 6
Keston Combi - Installation and Servicing 53
SERVICING
70 DhW FLOW REgULATOR CLEANINg / REpLACEMENT
1. Refer to Frame 45.
2. Isolate the mains cold water supply to the boiler.
3. Drain the boiler DHW circuit. Refer to Frame
60.
4. Remove the DHW flow turbine cartridge.
Refer to Frame 69.
5. Unscrew the flow regulator housing.
6. Inspect the flow regulator for any blockage and remove if necessary.
7. Reassemble in reverse order.
8. Refill the boiler. Refer to Frame 22.
9. Check Operation of the boiler. Refer to
Frame 36.
5
6
71 NO FLOW ThERMIsTOR REpLACEMENT
1. Refer to Frame 45.
2. Drain down the boiler. Refer to Frame 60.
3. Unplug the electrical lead.
4. Unscrew the thermistor (to facilitate removal a
13mm socket spanner should be used).
5. Fit the new thermistor using the sealing washer provided.
6. Reassemble in the reverse order.
7. Refill the boiler. Refer to Frame 22.
8. Check the operation of the boiler. Refer to Frame
36.
3
4
54 Keston Combi - Installation and Servicing
SERVICING
72 hEAT ENgINE RENEWAL
Refer also to Frame 6 - ‘Boiler Exploded View’
IMpORTANT
Before starting the removal procedure, protect the gas and electrical controls with a waterproof sheet or plastic bag.
1. Refer to Frame 45.
2. Drain the boiler. Refer to Frame 60.
3. Remove the fan / venturi assembly and place on one side.
Refer to frame 46.
4. Remove the burner and place on one side. Refer to Frame
48.
5. Remove the ignition and detection electrodes and diverter actuator head. Refer to Frames 51, 52 and 55.
6. Remove the spark generator. Refer to Frame 53.
7. Disconnect flue thermostat.
8. Remove the gas valve. Refer to Frame 54.
9. Remove the expansion vessel. Refer to Frame 73.
10. Remove the no flow thermistor. Refer to Frame 71.
11. Remove the 2 M5 screws retaining the gas valve mounting bracket and transfer bracket to the new heat exchanger.
12. Undo the inlet pipe union nut and remove the retaining spring clip and remove pipe.
13. Undo the flow pipe union nut and remove pipe.
14. Remove the condensate rubber pipe. Refer to Frame 56, no. 2.
15. Remove the two heat exchanger fixing screws.
16. Remove the Heat exchanger.
17. Reassemble in reverse order, ensuring the heat exchanger
LH retaining bracket is correctly positioned. Replace any new ‘o’ rings supplied with new heat exchanger and replacing gaskets or seals if any sign of damage is evident. When replacing the spring clips located on both the flow and return pipe connections, ensure clip is oriented to correctly match connecting pipe diameters.
18. Ensure the trap/siphon is filled with water. Refer to Frame 56.
19. Refill the boiler. Refer to Frame 22.
20. Check operation of the boiler. Refer to Frame 36.
13
11
Keston Combi - Installation and Servicing
15
12
55
SERVICING
73 ExpANsION VEssEL REChARgINg & REpLACEMENT
REChARgINg
1. Refer to Frame 45.
2. Remove the charge point cover.
3. Recharge the tank pressure to 0.75 bar.
4. Re-assemble in reverse order
5. Check operation of the boiler. Refer to Frame36.
REpLACEMENT
6. Refer to Frame 45.
7. Drain the boiler CH circuit. Refer to Frame 60.
8. Unscrew the union nut on the vessel water connection pipe.
9. Support the expansion vessel and unscrew the 2 screws from the securing clamp, located on the top of the boiler, and remove. (Note the position of the bracket on the vessel)
10. Remove the expansion vessel.
11. Fit the new expansion vessel.
12. Reassemble in reverse order.
13. Refill the boiler. Refer to Frame 22.
14. Check operation of the boiler. Refer to Frame 36.
3
9
74 BOILER sEALINg pANEL sEAL REpLACEMENT
1. Refer to Frame 45.
2. Remove the old seal from the casing and thoroughly clean the casing surfaces.
3. Fit the new seal, ensuring the bottom joint provides an air tight seal.
5. Reassemble in reverse order.
6. Check operation of the boiler. Refer to
Frame 36.
Note. Ensure that the boiler front panel is correctly sealed, compressing the seal to make an airtight joint.
Recharge
Point
56 Keston Combi - Installation and Servicing
Fault Finding
75 FAULT FINDINg ChART MAIN MENU
Note. Boiler status display information is shown in shaded boxes below. Up to six messages will be displayed in rotation.
Overheat lockout
3 Check radiator valves open
Ignition lockout /
Flue Overheat
2 Reset boiler
1 Fill system to 1.0 bar
4 Reset boiler
2 Bleed radiators
5 Contact installer
1 Check other gas appliances work
3 Contact Installer
Go to Frame 76
Flow Temperature Overheat Lockout
Too many resets
Fault 8
Flame loss
Return thermistor fault
Outside sensor fault
Low mains voltage
PCB Fault
PCB Replaced
Flow thermistor fault
Boiler Chip Card Fault
12 month service interval request
No CH operation but DHW operates OK
No DHW operation but CH operates OK
No Display
Fan fault
Contact installer
Contact installer
Low water pressure 1 Fill system to 1.0 bar 2 Bleed radiators
1 Check other gas appliances
Contact installer
Contact installer
Contact installer
2 contact installer
Contact electricity provider
Contact installer
Reset boiler
Contact installer
Contact installer
Contact installer
3 Contact installer
Go to Frame 77
Ignition Lockout
5 Resets with 15 minutes
Turn power off and on
Go to Frame 78
False Flame Lockout
Go to Frame 79
Low Water Pressure
Go to Frame 80
Flame Loss
Go to Frame 81
Fan Fault
Go to Frame 82
Return Thermistor Fault
Go to Frame 83
Outside sensor fault
Low mains voltage
Contact Electricity Provider
If PCB is a spare check Boiler Chip Card
(BCC) fitted otherwise replace PCB
Reset the boiler
Go to Frame 82
Return Thermistor Fault
Go to Frame 85
BCC Fault
It is recommended to have the boiler serviced
Reset the boiler to clear message
Go to Frame 86
No CH operation but DHW works OK
Go to Frame 87
No DHW but CH operates OK
Go to Frame 88
No Display
REsET pROCEDURE - To reset boiler, turn mode knob to reset position and immediately turn knob back to required setting.
Keston Combi - Installation and Servicing 57
Fault Finding
76 OVERhEAT LOCKOUT - 1 FILL sysTEM TO 1.0 BAR - 2 BLEED RADIATORs -
3 ChECK RADIATOR VALVEs OpEN - 4 REsET BOILER - 5 CONTACT INsTALLER
NO Fill and vent the system and open all isolation valves, then reset boiler
Is the Boiler and CH System filled with water and all isolation and radiator valves open?
YES
Is the Flow/Return Differential across the Boiler in excess of 30°C?
NO
Check the Return Thermistor (Refer to Frame 49)
Check resistance using a suitable multimeter connected across the thermistor’s terminal pins
At 25 o C expect 9,700 - 10,300 Ohms
At 60 o C expect 2,400 - 2,600 Ohms
At 85 o C expect 1,000 - 1,100 Ohms
YES Check that the Pump is rotating freely. Is the Differential now below 20°C?
NO YES
Replace the Pump, then reset boiler
OK, now reset boiler
REsET pROCEDURE - To reset boiler, turn mode knob to reset position and immediately turn knob back to required setting.
58
77 IgNITION LOCKOUT / FLUE OVERhEAT - 1 ChECK OThER gAs AppLIANCEs WORK
- 2 REsET BOILER - 3 CONTACT INsTALLER
If the boiler is reset does the boiler ignite for a short time and then extinguish?
YES
Check the detection electrode and associated harness for: continuity, visual condition and position (Refer to
Frame 52). Check if the condensate pipe is blocked. Replace as necessary
NO
Check ignition electrode and associated harness for: continuity, visual condition and position. (Refer to Frame 51) Are these functioning correctly?
YES
YES NO
Check siphon and condensate drain pipe work for blockage and rectify if necessary. Boiler now working OK?
NO
Check flue for obstruction
NO
YES
YES Check wiring to thermostat
NO
Check flue temperature always remains below 90ºC
NO
YES
YES
Check if burner is damaged
NO
Replace heat exchanger
Is the Gas Pressure available at the Boiler Inlet (>18 mbar)?
YES
Is approx 215Vdc supply available at the Gas Valve? (* See note)
YES
Unplug gas valve. Is resistance between outside pins 4KΩ (±2)?
YES
Check spark generator and associated harness for: continuity and visual condition. (Refer to Frame 53) Are these functioning correctly?
Replace Ignition Electrode and associated harness as necessary
Clear obstruction
Ensure wiring correctly connected
Replace Thermostat
Replace burner
NO
NO
NO
NO
Check gas supply and rectify fault
Check wiring connection from gas valve to PCB for continuity. If the wiring is
OK then replace the PCB
Replace Gas Valve
Replace Spark
Generator and harness as necessary
* note: due to the wave form of the rectified voltage, the reading will vary depending on the type of meter used to measure the value. In general terms a reading greater than 150V indicates that the correct voltage is supplied to the gas valve.
REsET pROCEDURE - To reset boiler, turn mode knob to reset position and immediately turn knob back to required setting.
Keston Combi - Installation and Servicing
Fault Finding
78 FAULT 8 - CONTACT INsTALLER (FALsE FLAME LOCKOUT)
Reset the boiler, does Boiler Work OK?
NO
Separate the flame detection electrode in-line connector. Is there continuity between the terminals pins connected to the electrode?
NO
Check routing and integrity of internal boiler wiring.
YES
YES
Check routing and integrity of internal boiler wiring is OK. Check condition of Flame Sense
Electrode and replace if deteriorated.
Replace Flame Detection Electrode
REsET pROCEDURE - To reset boiler, turn mode knob to reset position and immediately turn knob back to required setting.
79 LOW WATER pREssURE - 1 FILL sysTEM TO 1.0 BAR - 2 BLEED RADIATORs -
3 CONTACT INsTALLER
Are the Boiler and CH System filled with water and all isolation and radiator valves open (check pressure gauge is between 1 to 1.5 bar)?
YES
Are connections on water pressure sensor secure?
YES
Replace water pressure sensor
NO
NO
Fill and vent the system and open all isolation valves
Re-fit connections
Keston Combi - Installation and Servicing 59
Fault Finding
80 FLAME LOss - 1 ChECK OThER gAs AppLIANCEs WORK -
2 CONTACT INsTALLER
Does the boiler ignite for a short time and then extinguish?
NO Is the Gas Pressure available at the Boiler Inlet (18 mbar)?
NO Check gas supply and rectify fault
YES
Check the detection electrode and associated harness for: continuity, visual condition and position (Refer to Frame 52). Check if condensate pipe is blocked. Check if flue is blocked.
Replace as necessary
YES
Is 215Vdc supply available at the
Gas Valve while the flame is on?
(* See note)
YES
Check spark generator and associated harness for: continuity and visual condition. (Refer to
Frame 53) Are these functioning correctly?
YES
NO
NO
Check wiring from gas valve to PCB for continuity.
If the wiring is OK then replace the PCB
Replace Spark Generator and Harness as necessary.
NO
Replace Ignition
Electrode and associated harness as necessary
Check ignition electrode and associated harness for: continuity, visual condition and position.
(Refer to Frame 51) Are these functioning correctly?
YES
Check siphon and condensate drain pipe work for blockage and rectify if necessary. Boiler now working OK?
NO
NO
Replace Gas Valve
Check flue for obstruction
YES
Clear obstruction
NO
Check wiring to thermostat
NO
Check flue temperature always remains below 90ºC
NO
Check if burner is damaged
NO
Replace heat exchanger
YES
YES
YES
Ensure wiring correctly connected
Replace Thermostat
Replace burner
60
* note: due to the wave form of the rectified voltage, the reading will vary depending on the type of meter used to measure the value. In general terms a reading greater than 150V indicates that the correct voltage is supplied to the gas valve.
Keston Combi - Installation and Servicing
Fault Finding
81 FAN FAULT - CONTACT INsTALLER
Does the wiring from the Fan to the PCB have secure connections at both ends and has not deteriorated? Does the wiring have continuity?
YES
Is there 230Vac at the Blue and Brown connections to the 3 way connection on the Fan?
NO
NO
YES
Rectify Wiring & connections
Replace PCB
Replace Fan
82 RETURN ThERMIsTOR FAULT - CONTACT INsTALLER
Remove the Return Thermistor from the CH Return
Pipe and disconnect the wires.
Check the resistance using a suitable multimeter connected across the thermistor’s terminal pins.
At 25
At 60
At 85 o o o
C expect
C expect
C expect
9,700 - 10,300 Ohms
2,400 - 2,600 Ohms
1,000 - 1,100 Ohms
Is the Thermistor value correct?
YES
Is there continuity between the PCB and the Thermistor?
NO
NO
YES
Fit a new Thermistor
Check and replace wiring as necessary
Replace PCB
83 OUTsIDE sENsOR FAULT - CONTACT INsTALLER
NO Securely connect the wiring at both the boiler and Outside Sensor
Is the wiring securely connected at both the boiler and
Outside Sensor?
YES
Check the resistance using a suitable multimeter connected across the Outside Sensor’s terminal pins.
At 0
Disconnect the wires to the outside sensor.
o C expect 31,000 - 35,000 Ohms
At 15 o C expect 15,000 - 16,500 Ohms
At 30 o C expect 7,700 - 8,500 Ohms
Is the Outside Sensor value correct?
YES
Is the wiring securely connected between the incoming terminal block boiler connection of the
Outside Sensor and the PCB?
NO
NO
YES
Fit a new Outside Sensor
Securely connect the wiring at the
Terminal Block and the PCB
Replace PCB
Keston Combi - Installation and Servicing 61
62
Fault Finding
84 FLOW ThERMIsTOR FAULT - CONTACT INsTALLER
NO
Is the wiring securely connected to the Flow Thermistor
(located in the top of the Heat Exchanger?)
YES
Disconnect the wiring from the Flow Thermistor
Check the resistance using a suitable multimeter connected across the Thermistor’s terminal pins.
At 25 o C expect 9,700 - 10,300
At 60 o C expect 2,400 - 2,600
At 85 o C expect 1,000 - 1,100
Ohms
Ohms
Ohms
Is the Thermistor value correct?
NO
YES
Securely connect the wiring to the Flow
Thermistor
Fit a new Thermistor
Is the wiring securely connected to the low voltage 6 way connector at the front left hand side of the PCB?
YES
Replace PCB
NO
Securely connect the wiring to the PCB
85 BOILER ChIp CARD FAULT - CONTACT INsTALLER
NO
Is the correct BCC for the boiler securely inserted into the slot at the front left of the PCB?
(identified by the label on the BCC)
YES
Replace the BCC with a new BCC (that is correct for the boiler). After switching power on and ‘c0’ being shown, reset the boiler. Is ‘c2’ still shown?
YES
Securely attach the BCC for the boiler onto the PCB and after switching power on and ‘c0’ being shown, reset the boiler.
Note. Ensure the correct orientation of BCC by placing “TOP” side up.
Replace PCB
REsET pROCEDURE - To reset boiler, turn mode knob to reset position and immediately turn knob back to required setting.
86 NO Ch OpERATION BUT DhW WORKs OK
Is the mode knob in the Winter position?
YES
Are the Timer and the Room Thermostat switched on?
YES
Are the Radiator Valves Open?
YES
Is there 230Vac at (A)?
YES
Replace the
Diverter Valve
NO
There is no Voltage from the
Timer/Room Stat. This is not boiler fault. Ensure Voltage is supplied to boiler by rectifying external wiring.
NO
NO
NO
Move the mode knob to the Winter position
Switch the Timer and Room Thermostat On
Open the Radiator Valves
A
Keston Combi - Installation and Servicing
Fault Finding
87 NO hW BUT Ch ON
Does the display show “hot water” -
“temperature XXºC” - “high efficiency”?
YES
Are the flow rates correct as per Frame 2.
YES
Is the wiring between the PCB and the diverter valve motor connected?
YES
NO
Check diverter head fully engaged and clip secured onto waterset.
YES
NO
NO
Is the red neon illuminated on the turbine sensor?
Adjust flow rates to achieve 35º temp rise and check filter fitted in turbine is not blocked with debris.
YES Is hot and cold
NO pipework crossed?
Replace PCB
NO
NO
Is diverter stuck in the CH position
YES
Check and replace diverter valve motor head.
Is Boiler DHW OK?
NO
Change diverter Valve cartridge - rear section
NO
Reconnect wiring or replace wiring harness if no continuity.
Re-engage diverter head and secure clip to wateset
Replace PCB
Is the wiring connected between PCB and DHW sensor?
YES
Remove the turbine, and check for debris in the turbine & filter. Replace turbine if necessary. Is
DHW OK?
NO
NO
Replace turbine sensor
Re-connect wiring
88 NO DIspLAy
Is there 230Vac to the boiler at L and N?
YES
NO
Is the wiring from the terminal block to the Main PCB connected securely?
YES
NO
Is the ribbon cable from the main PCB to the User
Interface PCB connected securely?
YES
Is ribbon cable damaged?
YES
NO
NO
Replace the
User Interface
PCB
Replace ribbon cable
Supply power to the boiler
Connect the wiring from the terminal block to the
Main PCB securely.
Connect the ribbon from the main PCB to the User
Interface PCB securely
L
N
Keston Combi - Installation and Servicing 63
SPARE PARtS
When replacing any part on this appliance use only spare parts that you can be assured conform to the safety and performance specification that we require. Do not use reconditioned or copy parts that have not been clearly authorised by Keston. Failure to do so could affect safety or performance of this appliance.
-
-
-
Our parts team are also available to help with your Keston spare parts enquiries on 01482 498665.
When calling, and to ensure we can provide you with the most accurate parts information, please ensure you have the following to hand;
Boiler Model
Appliance GC Number
Boiler Serial Number
64 Keston Combi - Installation and Servicing
Keston Combi - Installation and Servicing 65
Benchmark Commissioning and
Servicing Section
It is a requirement that the boiler is installed and commissioned to the manufacturers instructions and the data fields on the commissioning checklist completed in full.
To instigate the boiler guarantee the boiler needs to be registered with the manufacturer within one month of the installation.
To maintain the boiler guarantee it is essential that the boiler is serviced annually by a Gas Safe registered engineer who has been trained on the boiler installed.
The service details should be recorded on the Benchmark Service Interval
Record and left with the householder.
www.centralheating.co.uk
© Heating and Hotwater Industry Council (HHIC)
GAS BOILER SYSTEM COMMISSIONING CHECKLIST
This Commissioning Checklist is to be completed in full by the competent person who commissioned the boiler as a means of demonstrating compliance with the appropriate Building Regulations and then handed to the customer to keep for future reference.
CONTROLS
Automatic bypass to system
Boiler interlock
ALL SYSTEMS
CENTRAL HEATING MODE
Central heating return temperature
COMBINATION BOILERS ONLY
DOMESTIC HOT WATER MODE
Cold water inlet temperature
CONDENSING BOILERS ONLY
ALL INSTALLATIONS
Programmable room thermostat
Optimum start control
Combination Boiler
Fitted
Fitted
Fitted
Fitted
Yes
Yes mbar OR
OR mbar
Yes
Yes mbar OR
AND
AND
OR
Yes Temperature
Yes
² Ratio
² Ratio
Yes
Yes
Yes
Yes mbar
* All installations in England and Wales must be to Local Authority Building Control (LABC) either directly or through a
Competent Persons Scheme. A Building Regulations Compliance will then be issued to the customer.
SERVICE RECORD
It is recommended that your heating system is serviced regularly and that the appropriate Service Interval Record is completed.
Service Provider
SERVICE 01 SERVICE 02
AND
AND
² %
² % (Where Possible)
Signature
SERVICE 03
AND
AND
² %
² % (Where Possible)
Signature
SERVICE 04
AND
AND
² %
² % (Where Possible)
Signature
SERVICE 05
(Where Possible)
Signature
SERVICE 07
AND
AND
² %
² % (Where Possible)
Signature
SERVICE 06
AND
AND
² %
² % (Where Possible)
Signature
SERVICE 08
AND
AND
² %
² %
(Where Possible)
Signature
SERVICE 09
AND
AND
² %
² % (Where Possible)
Signature
SERVICE 10
AND
AND
² %
² %
(Where Possible)
AND
AND
² %
² % (Where Possible)
AND
AND
² %
² %
Signature Signature
* All installations in England and Wales must be to Local Authority Building Control (LABC) either directly or through a
Competent Persons Scheme. A Building Regulations Compliance will then be issued to the customer.
© Heating and Hotwater Industry Council (HHIC) www.centralheating.co.uk
FLOWCHART FOR CO LEVEL AND COMBUSTION RATIO
CHECK ON COMMISSIONING A CONDENSING BOILER
Important Preliminary Information on Checks
The air gas ratio valve is factory-set and must not be adjusted DURING COMMISSIONING.
If the boiler requires conversion to operate with a different gas family (e.g. conversion from natural gas to LPG) separate guidance is provided with the conversion kit supplied and this must be followed.
PRIOR TO CO LEVEL AND COMBUSTION RATIO CHECK
The installation instructions must have been followed, gas type verified and gas supply pressure / gas rate checked as required prior to commissioning.
As part of the installation process, ESPECIALLY WHERE A FLUE HAS BEEN FITTED BY PERSONS OTHER THAN
THE BOILER INSTALLER, visually check the integrity of the whole flue system to confirm that all components are correctly assembled, fixed and supported. Check that maximum flue lengths have not been exceeded and all guidance has been followed (e.g. Gas Safe Register Technical Bulletin (TB) 008 where chimney/flues are in voids).
The ECGA should be of the correct type, as specified by BS 7967.
Prior to its use, the ECGA should have been maintained and calibrated as specified by the manufacturer. The installer must have the relevant competence for use of the analyser.
Check and zero the analyser IN FRESH AIR in accordance with the analyser manufacturer’s instructions.
KEY:
CO = carbon monoxide
CO
2
= carbon dioxide
O2 = oxygen
Combustion Ratio = The CO reading measured in ppm divided by the CO
2
reading first converted to ppm
ppm = parts per million
GS(I&U)R = Gas Safety (Installation and Use) Regulations
70
*setting to Minimum Rate:
1. Turn the CH temperature control knob into the 10 O’clock position.
2. Create a CH demand by ensuring that the system controls are requesting heat and the boiler Mode
Knob is in the Winter Position.
3. Within an overall time of 3 seconds, turn the CH temperature control knob fully clockwise, back to
10 O’clock and then fully clockwise again.
4. The following messages will be shown in rotation on the display:
“Service Mode”
“Minimum Output”
“Move CH Knob to End” and the boiler output will be reduced to minimum.
5. The boiler will remain at minimum rate for 5 minutes before reverting to normal operation.
Keston Combi - Installation and Servicing
Start
Set Boiler to Maximum Gas Rate
In accordance with boiler instructions, set boiler to operate at maximum rate
(full load condition). Allow sufficient time for combustion to stabilise.
Note. Do not insert analyser probe during this period to avoid possible flooding of sensor.
Carry Out Flue Integrity Check Using Analyser
Insert analyser probe into air inlet test point (where available) and allow readings to stabilise.
Note. Where no air inlet test point is provided then a flue integrity check with the analyser is not possible. The installer should verify that flue integrity has been visually checked in accordance with the “ Prior to CO level and
combustion ratio check” (see opposite page) before proceeding to the
“ check CO level and combustion ratio at maximum rate” stage below.
Verify Flue Integrity
Analyser readings indicate that combustion products and inlet air must be mixing. Further investigation of the flue is therefore required.
Check that flue components are assembled, fixed and supported as per instructions. Check that flue and flue terminal are not obstructed.
No
Is
O2 more than or equal to 20.6% OR CO
2 less than or equal to
0.2%?
Yes
Is
O
2
more than or equal to 20.6% OR CO
2 less than or equal to
0.2%?
No
Yes
Turn off appliance and call Ideal Technical Helpline for advice
The appliance must not be commissioned until problems are identified and resolved. If commissioning cannot be fully completed, the appliance must be disconnected from the gas supply in accordance with GSIUR.
Check that no seals, e.g. Those on flue extensions, have been displaced during installation. Rectify if necessary.
Is
CO level less than 350ppm AND CO/CO
2 ratio less than
0.0040?
No
Yes
Check CO level and Combustion Ratio at Maximum Gas Rate
With boiler still set at maximum gas rate, insert analyser probe into flue gas sampling point. Allow readings to stabilise before recording.
No
Is
CO level less than 350ppm AND CO/CO
2 ratio less than
0.0040?
Yes
Set Boiler to Minimum Gas Rate
(*see opposite page)
In accordance with boiler instructions, set boiler to operate at minimum rate (to minimum load condition).
Allow sufficient time for combustion to stabilise.
Check CO and Combustion Ratio at Minimum Gas Rate
With boiler set at minimum rate, insert analyser probe into flue gas sampling point. Allow readings to stabilise before recording.
Turn off Appliance and Call Ideal Technical Helpline
The appliance must not be commissioned until problems are identified and resolved. If commissioning cannot be fully completed, the appliance must be disconnected from the gas supply in accordance with GS(I&U)R. NOTE:
Check and record CO level and combustion ratio at both maximum AND minimum rate before contacting Ideal.
No
Is
CO level less than 350ppm AND CO/CO ratio less than
0.0040?
2
Yes
Boiler is Operating Satisfactorily
No further actions required.
Ensure test points are capped, boiler case is correctly replaced and all other commissioning procedures are completed. Complete Benchmark
Checklist, recording CO and combustion ratio readings as required.
Keston Combi - Installation and Servicing 71
Keston heating, PO Box 103, National Avenue, Kingston Upon Hull, HU5 4JN
Tel. +44 (0) 1482 443005 Fax. +44 (0) 1482 467133. www.keston.co.uk
February 2014 UIN 207895 A03
Keston pursues a policy of continuing improvement i n t h e d e s i g n a n d p e r f o r m a n c e o f i t s p r o d u c t s .
The right is therefore reserved to vary specification without notice.
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