Keston C55, C40 Installation Manual

WD536	The Keston C45, C40P, C55 & C55P

C45 C40P C55 C55P

Fan Powered High Efficiency

Modulating Domestic Condensing Gas Boiler

Installation and Servicing Instructions

C45, C40P, C55 & C55P Models

ISSUE: 1/2010

CE/PI No : 87CL131

C45 - GC No : 41-930-25

CE/PI No : 87BN14

C40P - GC No : 41-930-08

C55 - GC No : 41-930-09

C55P - GC No : 41-930-10

These instructions must be left either with the user or next to the site gas meter.

KESTON BOILERS LIMITED

34 West Common Road, Bromley, Hayes, Kent BR2 7BX, UK Tel. [phone] Fax. [phone]

email : [e-mail] web : www.keston.co.uk

COMPLIANT WITH BUILDING REGULATION PART L1 & L2 2002

SEDBUK A RATED

WD536	The Keston C45, C40P, C55 & C55P

	CONTENTS
Section	Description
0	HANDLING INSTRUCTIONS
0.1	List of contents
0.2	Recommended handling procedure
1	GENERAL INSTRUCTION
1.1	Description
1.2	Boiler Schematic
1.3	Related Documents
1.4	Physical Data
1.5	Performance Data C45 and C40P
1.6	Performance Data C55 and C55P
1.7	Optional Accessories
2	BOILER LOCATION
2.1	Dimensions & Minimum Clearances
2.2	Service Connections
2.3	Position
2.4	Electrical
2.5	Boiler Size Selection
2.6	Gas Supply
2.7	Water Systems
2.8	Flue System
2.9	Air Supply
2.10	Compartment Installation
2.11	Condensate Drainage
3	INSTALLATION OF THE BOILER
3.1	Wall Mounting Bracket
3.2	Mounting The Boiler
3.3	Assembly Practice
3.4	Installing Flue And Air Pipes
3.5	Condensate Drainage
3.6	Water System
3.7	Gas Supply
3.8	Electrical Supply
3.9	Exchanging A Boiler

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WD536		The Keston C45, C40P, C55 & C55P
4	COMMISSIONING OF THE BOILER
4.1		Initial Flushing
4.2		Gas Supply
4.3		Electrical Installation
4.4		LP Gas
4.5		Initial Firing
4.6		Hot Flushing
4.7		Combustion Testing
4.8		Checking The Gas Pressure
4.9		Timing The Gas Meter
4.10		Handing Over To The User
5	FAULT FINDING
5.1		Electrical Control Sequence
5.2		Normal Operation
5.3		Fault Modes
5.4		Functional Flow Wiring Diagram
5.5		Electrical Wiring Diagram
5.6		Illustrated Wiring Diagram
5.7		Exploded Assembly Diagrams
6	SERVICING
6.1		Pre Service Checks
6.2		Recommended Routine Service
7	REPLACEMENT OF PARTS
7.0		General
7.1		Precautions
7.2		Access
7.3		Replacement Procedure
7.4		Electrical Components
7.5		Spark Ignition/Flame Detection Electrode
7.6		Burner
7.7		Heat Exchanger
7.8		Condensate Trap
7.9		Pump
8	SPARE PARTS LISTINGS
9	GAS BOILER COMMISSIONING CHECKLIST

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WD536	The Keston C45, C40P, C55 & C55P

0. HANDLING INSTRUCTION

0.1LIST OF CONTENTS

The Keston C40P,C45 and C55(P) are supplied almost totally pre-assembled. Since the units use standard 50 mm muPVC pipe for the flue and air intake systems the boiler is packed in a single box without additional flue kit. All additional components are packed inside the boiler cabinet itself. The following is a list of components and their location in the boiler cabinet

Equipment List
Item	Quantity	Location
Wall Bracket Rawl Plugs	5	Inside accessories bag
Wall Bracket Wall Fixing Screws	5	Inside accessories bag
Wall Mounting Bracket	1	Secured to inside right hand
		side of boiler case
Wall Mounting Bracket Nuts	2	Inside accessories bag.
Wall Mounting Bracket Washers	2+2	Inside accessories bag
Gas Cock (22 mm cxc)	1	Inside accessories bag
50 mm muPVC Air/Flue Terminals	2	Inside accessories bag
Flue Spigot Nipple	1	Inside accessories bag
Cabinet Cable Entry Clamps	2	Inside accessories bag
User Control Knobs	2	Inside accessories bag
Outside Temperature Sensor	1	Inside accessories bag
Document List
Item	Quantity	Location
User Instructions	1	In A4 envelope
Lifting Instructions	1	In A4 envelope
Installer Notice	1	In A4 envelope
Registration of Purchase - 2 YEAR Guarantee	1	In A4 envelope - C45&C40P
2 YEAR Warranty Plan	1	In A4 envelope - C45&C40P
12 Month Guarantee	1	In A4 envelope - C55&C55P
Installation Template	1	In document bag

Remove the cabinet shell by removing the four retaining screws in the top of the cabinet and the three retaining screws in the bottom of the cabinet.

0.2Recommended Handling Procedure

Before hanging the appliance on the wall it is best to store the appliance laid on its back with the casing on. When ready to hang the boiler on the wall remove the casing and place to one side. At this stage it is assumed that the wall bracket is correctly secured on the wall face.

a)Have the wall bracket nuts and washers to hand so that they can be accessed whilst holding the boiler in position on its mounting bracket.

b)The boiler has a dry weight of 61.5kg (136 lbs) and will therefore require at least two people to lift without the use of lifting aids.

c)Lift the boiler by gripping at the four corners of the boiler back plate. When lifting this appliance the back should be kept straight at all times. Avoid twisting at the waist - reposition the feet instead. Avoid upper body bending when holding the appliance and keep the boiler as close to the body as possible.

d)Lift the boiler and locate onto the two studs of the wall mounting bracket.

e)Hold the boiler on the wall bracket by applying pressure onto the front surface of the heat exchanger.

f)Place the wall mounting bracket washers over the bracket studs protruding through the back plate of the boiler.

g)Secure the boiler onto the wall bracket by fixing the wall mounting bracket nuts onto the wall bracket studs. These should be tightened well.

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WD536	The Keston C45, C40P, C55 & C55P

In the event the appliance must be fitted by one operative the integral circulating pump head and complete combustion fan/gas valve/venturi assembly can be removed from the appliance prior to lifting. However, the resulting weight will still be higher than considered acceptable for a one-man lift.

Safety footwear and gloves are recommended PPE when lifting this appliance.

The C45 and C55 boilers can be fitted in compartments with very small clearances required around the appliance (refer to Section 1.4). Due consideration should therefore be given to access within the compartment for lifting and positioning.

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WD536

Chapter 1 : General Instruction

The Keston C45, C40P, C55 & C55P

1. GENERAL INSTRUCTION

1.1DESCRIPTION

The Keston C45, C40P and C55(P) are unique in concept and design. They comprise a high efficiency stainless steel heat exchanger coupled with a low emissions burner to deliver ultra high efficiency condensing mode operation within a compact wall hung cabinet. The unit automatically adjusts gas and air rate according to demand to give an output in the range of 12.6kW to 44.9kW (C45 & C40P) and 14.3kW to 55.2kW (C55 & C55P). The integral Grundfos pump is automatically controlled to best match water flow rate to heat output & further increase appliance efficiency. In addition, they feature an optional connection for an outside sensor to enable the boilers inbuilt weather compensation option. Separate inputs are provided for hot water and central heating demand signals to enable different temperature levels to be set (ideal for underfloor heating systems). While the application for which the C45, C40P and C55(P) were designed is the same as those which other boilers are used, the Keston C45, C40P and C55(P) have the added advantage of very high efficiency, and small diameter plastic flue which can be extended up to 45 metres horizontally or vertically.

The Keston C45, C40P and C55(P) uses a variable speed combustion blower to deliver a premix of gas and air to a downward firing burner in a high efficiency, single pass heat exchanger. The flue system is room sealed and fan powered. The ignition is direct spark and fully automatic. The boiler housing is not waterproof and should be installed in a position where it will always be dry. Combustion air is drawn from the cabinet which is connected to outside atmosphere via a small diameter plastic intake pipe. The cabinet therefore remains under negative pressure at all times the boiler is operating.

The boiler is suitable for connection to open vented or, preferably, sealed systems.

The boiler heat exchanger is made from highly corrosion resistant stainless steel in corrugated pipe form which provides massive surface area within a compact dimension. The hot combustion gases from the down firing burner pass around the stainless steel pipes imparting heat into the system water. The integral variable speed Grundfos pump within the appliance cabinet ensures the heat exchanger receives correct water flow when firing. The C45, C40P and C55(P) are not high water content boilers and do not contain the metal mass, or water volume, of a cast iron or steel boiler. These boilers are of low mass and low water content and therefore responds faster when there is a call for heat. The C45, C40P and C55(P) feature full user diagnostics, integral frost protection function, automatic pump and fan exercise in periods of inactivity, anti cycle control, dry fire protection and connections for remote lockout and run monitoring (optional accessory).

1.2BOILER SCHEMATIC

Air is drawn into the boiler through a 50 mm muPVC (BS5255 and/or BSEN1566-1 and BSEN1329) plastic pipe or, alternatively, via a 75mm composite plastic pipe. Gas is mixed with combustion air at the inlet to the fan. The gas flow is automatically regulated by the gas valve according to the air flow generated by the fan. The gas and air are thoroughly mixed in the blower and fed into the burner located at the top end of the heat exchanger module. The gas and air mixture is ignited by a direct spark ignition control system and burns with a blue flame just off the surface of the burner. As the hot products of combustion pass downwards, they are cooled by exchanging heat with the circulating water which enters the heat exchanger at the bottom of the heat exchanger. The optimum heat input is detected by monitoring flow and return temperatures and is adjusted by controlling the speed of the fan. The optimum pump speed is also detected and automatically selected by the boiler.

When the return water temperature is below 55oC, part of the water vapour in the combustion products will condense inside the heat exchanger, thus increasing the boiler efficiency further by releasing the latent heat of condensation. This condensate falls to the bottom of the heat exchanger where it is separated from the flue gases and exits from the boiler through the condensate drain. Any condensate formed in the flue runs back down

Installation & Servicing Instructions

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WD536	Chapter 1 : General Instruction The Keston C45, C40P, C55 and C55P

the flueway and is drained at the base of the flue connection to the heat exchanger or drain points within the flue.

Fig. 1.2 - Boiler Layout

The condensate is very slightly acidic (about the same acidity as vinegar) and should be piped in a plastic pipe. It is not harmful to the waste disposal system and may be disposed of as normal waste water.

The flue gases are piped in a 50 mm muPVC (BS5255 and/or BSEN1566-1 and BSEN1329) plastic or, alternatively, 75mm composite plastic pipe to the outside. The temperature of the flue gases are usually around 5oC to 10oC above the temperature of the return water. The flue pipe should be terminated outside the building from where they cannot re-enter the building or any other adjacent building.

The heating level may be controlled by room thermostats, hot water calorifier thermostats, programmer time clocks and energy management systems. A Keston room controller can be connected which will provide enhance controls such as room compensation and optimum start to further increase efficiency and comfort levels.

The C45, C40P and C55(P) feature an integral frost protection function which will operate the pump, regardless of the external controls, should the boiler temperature fall below 7oC. In the event the boiler temperature falls below 3oC the boiler will also fire. This is to avoid damage to the boiler through freezing of boiler water. The boiler will turn off when the flow temperature exceeds 10oC.

The C45, C40P and C55(P) feature an integral pump exercise function which will run the pump, without firing the boiler, for 10 seconds in the event the boiler is on standby for in excess of 24 hours without firing. This is to help prevent seizing of the pump due to long periods of inactivity.

1.3RELATED DOCUMENTS

The Keston C45, C40P and C55(P) Condensing Boiler must be installed in accordance with the current issue of the Gas Safety (Installation and Use) Regulations 1996, current IEE Wiring Regulations, Building Regulations, Building Standards (Scotland) Consolidation, and the Bye Laws of the local Water Undertaking.

Installation & Servicing Instructions

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WD536

Chapter 1 : General Instruction

The Keston C45, C40P, C55 & C55P

In addition, due account must be taken to the following Codes Of Practice:

BS 6891	:	Low Pressure Installation Pipes
BS 6798	:	Installation of Gas Fired Hot Water Boilers of
		Rated Input Not Exceeding 70kW
BS 5449	:	Installation Pumped Central Heating
BS 5546	:	Installation of Gas Hot Water Supplies for
		Domestic Purposes (2nd family gases)
BS 5440.1	:	Flues (for gas appliances of rated input not
		exceeding 70kW)
BS 5440.2	:	Air Supply (for gas appliances of rated input not
		exceeding 70kW)
BS 5482.1	:	Domestic Propane and Butane Burning
		Installations
BS 7074.1	:	Expansion Vessels
BS 7593	:	Treatment of Water in Hot Water Central Heating
		Systems
BS 7671	:	Requirements for Electrical Installations. IEE
		Wiring Regulations 16th Edition.
BSEN 12828:2003	:	Heating Systems in Buildings: Design for water
		based heating systems
BSEN 12831:2003	:	Heating Systems in Buildings: Method for
		calculation of design heat load
BSEN 14336:2004	:	Heating Systems in Buildings: Installation and
		commissioning of water based heating systems

For Timber Framed Buildings, British Gas Publications DM2. Also British Gas Publications 'Guidance Notes For The Installation Of Domestic Gas Condensing Boilers' and 'Specification For Domestic Wet Central Heating Systems'.

1.4PHYSICAL DATA - C45 and C55

		Cabinet Height		mm	720
		Cabinet Width		mm	520
		Cabinet Depth		mm	320
		Top Clearance		mm	150
		Side Clearance		mm	25
		Base Clearance		mm	150
		Front Clearance (for servicing)		mm	305
		Weight - Full		kg / (lbs)	70.5/(157.8)
		Weight - Empty		kg / (lbs)	61.5/(135.8)
		Flow and Return Connection			Rp 1" F
		Gas Connection			Rp 0.75" F
		Condensate Connection		mm	22mm plastic overflow
		IP Rating			IP20 (IPX0)
		Flue and Air Intake Material	50mm muPVC (BS5255 and/or BSEN1566-1 and BSEN1329)
		Flue Pipe Size (nominal bore)		mm / (in)	50 / (2)
		Air Intake Pipe Size (nominal bore)		mm / (in)	50 / (2)
		Max. Air Intake Length		m	29
		Max. Flue Outlet Length		m	15
		Max. Total Flue Outlet and Air Intake Length		m	30
		Flue and Air Intake Material		75mm Keston Composite
		Flue Pipe Size (nominal bore)		mm / (in)	75 / (3)
		Air Intake Pipe Size (nominal bore)		mm / (in)	75 / (3)
		Max. Air Intake Length		m	87
		Max. Flue Outlet Length		m	45
		Max. Total Flue Outlet and Air Intake Length		m	90

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WD536	Chapter 1 : General Instruction The Keston C45, C40P, C55 and C55P

1.5PERFORMANCE DATA - C45 & C40P

		C45	C40P
Nat. Gas (G20)	LPG (G31)
Min. Input (Gross CV)	kW/(Btu/h)	12.9/(43,900)	12.6/(43,000)
Max. Input (Gross CV)	kW/(Btu/h)	45.6/(155,600)	43.2/(147,400)
Max. Output To Water
(80/60oC Flow/Return)	kW/(Btu/h)	40.3/(137,600)	39.1/(133,300)
(50/30oC Flow/Return)	kW/(Btu/h)	44.9/(153,400)	43.2/(147,400)
Min. Output To Water
(80/60oC Flow/Return)	kW/(Btu/h)	11.3/(38,500)	11.4/(38,800)
(50/30oC Flow/Return)	kW/(Btu/h)	12.6(43,000)	12.6(43,000)
Max. Burner Press.-Hot (Factory Preset)	mbar/(in w.g)	0	0
Gas Consumption After 10 mins	l/s / (Ft3/hr)	1.21/(153.4)	0.451/(57.4)
Max. Operating Flow Temp.	oC	82.00	82.00
Max. Head (Open Systems)	m / (ft)	30.50 / (100)	30.50 / (100)
Max. Press. (Sealed System)	bar	2.70	2.70
Min. Head (Open Systems)	m	3.0	3.0
Inlet Gas Pressure	mbar/(in w.g)	20.0 / (8.0)	37.0/(14.8)
Recommended Temp Diff.	oC	8 to 20	8 to 20
Electrical Supply		230V 50Hz	230V 50Hz
Power Consumption (Max)	W	260	260
Power Consumption (Standby)	W	8	8
Type of Gas		G20 Natural Gas	G31 LPG
Optimum Flue Gas CO2 Level	%	8.3 ±0.2	9.9 ±0.2
Expected CO/CO2 Ratio (at max rate)		0.001	0.0013
Destination Countries		GB/IE	GB/IE
SEDBUK Efficiency		90.4%	92.5%

1.6PERFORMANCE DATA - C55 & C55P

			C55	C55P
			Nat. Gas (G20)	LPG (G31)
	Min. Input (Gross CV)	kW/(Btu/h)	14.3/(48,800)	14.8/(50,500)
	Max. Input (Gross CV)	kW/(Btu/h)	56.5/(192,800)	53.4/(182,300)
	Max. Output To Water
	(80/60oC Flow/Return)	kW/(Btu/h)	49.7/(169,700)	48.0/(163,900)
	(50/30oC Flow/Return)	kW/(Btu/h)	55.2/(188,500)	53.4/(182,300)
	Min. Output To Water
	(80/60oC Flow/Return)	kW/(Btu/h)	12.5/(42,900)	12.9/(44,100)
	(50/30oC Flow/Return)	kW/(Btu/h)	14.3/(48,800)	14.8/(50,500)
	Max. Burner Press.-Hot (Factory Preset)	mbar/(in w.g)	0	0
	Gas Consumption After 10 mins	l/s / (Ft3/hr)	1.50/(190.1)	0.54/(68.3)
	Max. Operating Flow Temp.	oC	82.00	82.00
	Max. Head (Open Systems)	m / (ft)	30.50 / (100)	30.50 / (100)
	Max. Press. (Sealed System)	bar	2.70	2.70
	Min. Head (Open Systems)	m	3.0	3.0
	Inlet Gas Pressure	mbar/(in w.g)	20.0 / (8.0)	37.0/(14.8)
	Recommended Temp Diff.	oC	8 to 20	8 to 20
	Electrical Supply		230V 50Hz	230V 50Hz
	Power Consumption (Max)	W	260	260
	Power Consumption (Standby)	W	8	8
	Type of Gas		G20 Natural Gas	G31 LPG
	Optimum Flue Gas CO2 Level	%	8.8 ±0.2	10.2 ±0.2
	Expected CO/CO2 Ratio (at max rate)		0.001	0.0013
	Destination Countries		GB/IE	GB/IE
	SEDBUK Efficiency		90.2%	92.2%

Installation & Servicing Instructions

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WD536

Chapter 1 : General Instruction

The Keston C45, C40P, C55 & C55P

Keston Boilers Ltd declare that there are no substances harmful to health within the appliance or used during the production of the appliance.

The C45 and C55 are intended for domestic and commercial EMC environments and on a governed G20 meter supply.

The C40P and C55P is intended for domestic and commercial EMC environments and on a governed G31 supply.

Seasonal Efficiency (SEDBUK) = 90.4% (C45), 92.5% (C40P), 90.2% (C55) & 92.2 (C55P)

This 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 Advantica Technologies Ltd.

IMPORTANT

This product contains ceramic fibre boards, which although not regarded as a risk, contain ceramic fibre which may cause temporary irritation to eyes, skin and respiratory tract. The fibres are held in place by inorganic binders. Therefore as long as the boards are not disturbed they will not be released. Since the boards are non-serviceable parts there should be no risk.

To ensure that the release of fibres from these RCF articles is kept to a minimum, during installation and servicing we recommend that you use a HEPA filtered vacuum to remove any dust accumulated in and around the appliance before and after working on the appliance. When replacing these articles we recommend that the replaced items are not broken up, but are sealed within heavy duty polythene bags, and clearly labelled as RCF waste. RCF waste is classed as a stable, non-reactive hazardous waste and may be disposed at a landfill licensed to accept such waste. Protective clothing is not required when handling these articles, but we recommend you follow the normal hygiene rules of not smoking, eating or drinking in the work area and always wash your hands before eating or drinking.

This appliance is not intended for use by persons (including children) with reduced physical, sensory or mental capabilities, or lack of experience and knowledge, unless they have been given supervision or instruction concerning use of the appliance by a person responsible for their safety.

Children should be supervised to ensure that they do not play with the appliance.

BENCHMARK INITIATIVE

As part of the industry wide “Benchmark” initiative C45, C40P & C55(P) boilers manual includes Gas Boiler Commissioning Checklist (Chapter 9). This form should be completed by your installer at the end of the installation and commissioning process.

The details of the Checklist will be required in the event of any warranty work being required. There is also Service Interval Record (Chapter 9) to be completed after each annual service visit.

These forms (Chapter 9) should be kept in a safe place for the life of the boiler.

GAS SAFE REGISTER INFORMATION

The boiler should be installed and serviced only by GAS SAFE REGISTER registered operatives. All GAS SAFE REGISTER registered Installers carry a GAS SAFE REGISTER ID card and have a registration number. Both should be recorded in your boiler manual (Chapter 9: GAS BOILER COMMISSIONING CHECKLIST). You can check your installer by calling GAS SAFE REGISTER direct on 0800 408 5500.

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WD536	Chapter 1 : General Instruction The Keston C45, C40P, C55 and C55P

1.7OPTIONAL ACCESSORIES

A range of accessories are available from Keston Boilers Ltd to compliment an installation. Terminal wall sealing collars are available to make good the external all face whilst working from the inside of the building using 50mm muPVC (BS5255 and/or BSEN1566-1 and BSEN1329) pipe or 75mm (actual dimensions are int.dia. = 68mm, ext.dia. = 78mm) Keston Composite pipe. Stand-off frames are available to leave a 50mm gap behind the boiler to allow routing of pipes behind the boiler.

Description	Part Number
Flue Terminal Wall Sealing Collar (50mm)	C.08.0.00.07.0
Air Terminal Wall Sealing Collar (50mm)	C.08.0.00.07.0
50/75mm Flue Adapter	C.17.2.00.60.0
Flue Outlet Terminal (75mm)	C.17.2.26.00.0
Air Inlet Terminal (75mm)	C.17.2.26.00.0
Stand Off Back Plate	C.17.0.02.00.0
Keston Chronotherm Room Controller	C.17.4.21.00.0

Installation & Servicing Instructions

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WD536	Chapter 2 - Boiler Location The Keston C45, C40P, C55 & C55P

2. BOILER LOCATION

2.1DIMENSIONS AND MINIMUM CLEARANCES

The boiler must be installed in minimum clearances shown to allow subsequent servicing, and safe operation. However, larger clearances may be required during installation.

2.2SERVICE CONNECTIONS

Gas, water, air and flue pipe, condensation, and electrical connections are as shown. Gas : 0.75 inch BSP female. Flow/Return 1 inch BSP female.

An optional stand-off frame is also available which mounts behind the boiler to leave a 50mm deep space behind the boiler. This is to permit pipe routing behind the boiler if required. See Section 1.5 - Optional Accessories.

2.3POSITION

The C45, C40P and C55(P) are not suitable for external installation. The boiler may be installed in any room or internal space, although particular attention is drawn to the requirements of the current IEE Wiring Regulations and, in Scotland, the electrical provisions of the Building Regulations applicable in Scotland, with respect to the installation of the boiler in a room or internal space containing a bath or shower.

Where a room-sealed appliance is installed in a room containing a bath or shower, any electrical switch or appliance control, utilising mains electricity, should be so situated that it

ALL DIMENSIONS IN MM.

150

25	25
305	(W hen servicing appliance )
10	(W hen appliance is operating )
	Figure 2.1.1
	150 Minimum Clearances
Figure 2.1.2
Dimensions	ALL DIMENSIONS IN
Air Intake	mm
Flue

720

520	3	2	0

Base View

42	Air	Flue	51	485
				249
	65			117
			38	36
	447

Top View	Gas	Return	Flow	Condense
Service Connection Locations
	ALL DIMENSIONS ARE IN MM.

Installation & Servicing Instructions

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WD536 Chapter 2 - Boiler Location The Keston C45, C40P, C55 & C55P

cannot be touched by a person using the bath or shower. The C45, C40P and C55(P) are classified as IP20 (IPX0) and are therefore suitable for installation in Zone 3 areas, unless subject to hose down.

Compartment installation is permitted - such compartments must be constructed in accordance with BS 6798.

The wall on which the boiler is mounted must be of suitable load bearing capacity and must be non-combustible.

The Keston C45 and C55 can be located virtually anywhere desired provided that all

	Chimneys not used for
	venting any other
	appliance may be used.
	Secure air & flue pipes at
	chimney outlet.
[NB: Refer to	Figure 2.3
Section 2.8.3]

regulations are complied with. Because of the boiler's compact size and venting flexibility, the installation is not limited to a boiler room setting. Before locating the boiler near a living space consider whether the sounds generated by the boiler will be objectionable. The boiler may be located within a cupboard enclosure to reduce noise levels if located within a living space. LPG boilers must not be installed in a cellar.

2.4ELECTRICAL

2.4.1Electrical Connections

The boiler must be connected to a permanent 230V ~ 50Hz supply, fused at 3A.

The boiler has two thermostats and will therefore accept up to two switched live signal inputs at 230V, such as heating and hot water demand. For single signal systems switched live 1 may be used on its own. In the event the boiler receives a signal from both inputs at the same time the setting of thermostat 2, usually used for hot water demand, will take priority. Wiring external to the boiler must be in accordance with current I.E.E wiring regulations and local regulations.

The method of connection to the mains electricity supply must facilitate complete electrical isolation of the boiler, preferably by the use of a fused, unswitched three pin plug and a shuttered socket-outlet, both complying with the requirements of

Installation & Servicing Instructions

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WD536	Chapter 2 - Boiler Location The Keston C45, C40P, C55 & C55P

BS 1363. There must be only one common method of isolation for the boiler and its control system.

The appliance must be connected to the 3A supply via a fused double-pole switch having at least 3 mm (1/8 inch) contact separation in both poles, serving only the boiler and the system controls.

The connection point to the mains supply should be readily accessible and adjacent to the boiler, except for rooms containing a bath or a shower. Refer to section 2.3 Position.

2.4.2External Wiring & Controls

1.The boiler is designed so that all control wiring is external to the boiler.

2.A programmer may be used with zone valves to give independent control of central heating and hot water.

3.A Keston Chronotherm controller may be used to provide room compensation and optimum stop/start control on heating only systems

4.Control signal inputs must the 230VAC "switched live" type.

5.A Keston outside temperature sensor may be connected as an option. The boiler will automatically detect this connection and will operate on a "weather compensation" basis when receiving a signal on switched live 1. Screened cable (80% density) must be used to connect the outside temperature sensor.

		Brown
	V4043H1106	Blue
		Grey
	Zone Valve
		Orange
	Heating
		Green/Yellow
		White
		Brown
	V4043H1056	Blue
	Zone Valve	Grey
	DHW	Orange
		Green/Yellow

5							Room Thermostat		1
									3
2	Mains Supply			Live		1	T6360B1028
									2
1				Neutral		2
	Fused @ 3A
9				Earth		3
	230V
3									L
N/U							KESTON		N
									E
							C55 / C45
		L				1		SL1
8	Programmer	N				2		SL2
2	ST6300A	1				6		EX1
1		3						EX2
10		4				4
3
							Keston Spa				C
						6	Cylinder Stat				1
	Cyl. Thermostat	C					OR				2
		1				8
	L641A1039
		2					Keston Spa				C
											1
							Overheat Stat
											2

4

5 2

1

2

3

9

10

To Keston

Ext. Sensor [Optional]

6

8

2.4.4Wiring Expample - Honeywell S-Plan for DHW and (Optional) Weather Compensated Heating Control

2.5BOILER SIZE SELECTION

The C45, C40P and C55(P) will automatically adjust heat output and pump speed to match the system requirements at any given time. Efficiency and combustion levels are maintained at optimum levels throughout the possible output range. The C45, C40P and C55(P) are therefore suitable for all systems with a total heat load within the maximum range of the boiler.

2.6GAS SUPPLY

A gas meter should be connected to the service pipe by the local gas region or their contractor. An existing meter should be checked preferably by the gas region to ensure that the meter is adequate to deal with the rate of gas supply required. Installation pipes should be fitted in accordance with BS 6891.

Minimum/Maximum Gas Pressure:

Natural gas pressure before the gas valve must be maintained at between 18 mbar (7.2 in WG) and 22 mbar (8.8 in) while the boiler is running.

LPG pressure must be maintained between 31.5 mbar (12.4 in w.g) and 37.6 mbar (14.8 in w.g) while the boiler is running.

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WD536	Chapter 2 - Boiler Location The Keston C45, C40P, C55 & C55P

Gas pressures above or below these levels will lead to problems associated with the gas valve's internal pressure regulator.

Supply pipes to the boiler must not be sized less than the boiler inlet connection (22 mm). Due consideration must be given to the supply pressure to other gas appliances in the premises. Reduction in dynamic gas supply pressure will result in intermittent ignition failures. Ensure gas supply pipe work is adequately sized for the length of run from the meter to the boiler at a supply rate of 46kW for the C45 and 57kW for the C55 model.

A gas cock is supplied loose with the boiler. This cock should be fitted in the gas line to the boiler as close to the boiler as possible so that it is easily identified as the cock to isolate the boiler.

2.7WATER SYSTEMS

All piping must be installed in accordance with all applicable local and Water Supply Bylaws for forced hot water heating systems.

Consideration must be given to pipe capabilities and pressure drop through the piping when selecting pipe sizes. The primary pipe connections to the boiler must be sized according to the system load, not dictated by the boiler connection sizes.

Water treatment must be carried out to BS 7593 : Treatment of Water in Hot Water Central Heating Systems.

a The C45, C40P and C55(P) are suitable for use on open, vented water systems with combined feed and vent fitted to the boiler return.

b It is preferable for use on sealed water systems, provided the appropriate components required (see Section 2.7.2 Sealed Systems) are included in the system.

c Any system must be thoroughly flushed clean of grease, dirt and debris, prior to connection with the boiler. A trap may be installed in the flow line to collect any solder, or other debris, from the installation.

d All water systems must be constructed to comply with requirements of the Local Water Authority.

eAlways use a system complying with the requirements of BS 5449 and BS 6798.

fSystem design must ensure an open circuit is always available to ensure circulation when the pump overrun function is operating after boiler shutdown.

gCopper tubing to BS 2871 Part 1 or barrier plastic pipe suitable to 110 oC, such as Unipipe, is recommended.

hJointing should be either with capillary, threaded or compression fittings. Pipes should have a gradient to ensure air is passed easily to vent points and water flows readily to drain points.

iDraining taps must be located in accessible positions which permit the draining of the boiler and hot water storage vessel. Draining taps should be at least 22 mm in nominal size and be in accordance with BS 2879.

AIR VENT POINTS

jThese must be fitted at all high points where air will naturally collect and must be sited to allow complete draining of the system.

k.Where thermal stores are to be used the thermal store supplier should be consulted as to the compatibility of the thermal store with a Keston C45, C40P and C55(P). Thermal store units where the boiler directly heats an open vented thermal store are not suitable for use with the C45, C40P or C55(P).

2.7.1Open Vented Systems

A typical system is shown in Figure 2.7.1 which includes a combined feed and vent. Note that the combined feed and vent must be fitted to the primary RETURN. A safety valve is specified for the primary flow to ensure discharge path at all times in the event the feed/vent connection is isolated from the boiler flow [see 2.7.2(i)]. However, in the event the system is configured with no isolation valve on the primary flow and wired such the boiler cannot fire when all zone

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WD536	Chapter 2 - Boiler Location The Keston C45, C40P, C55 & C55P
		Figure2.7.1 : Open Vented System
	Expansion	Expansion
		Tank
	Pipe
		Minimum
		9ft Height
C45		28mm
or
	Safety	Minimum
C55	Valve		Cylinder
	(See note 2.7.1)	Valve

FLOW	L/S
	Valve
RETURN	By-pass

Valve

Rad. 2

Rad. 1

valves are closed, then the safety valve may be omitted. Note that the minimum static head required is 9 ft at the top of the boiler.

Although suitable for open vented systems with combined feed and vent arrangements, the C45, C40P and C55(P) are low water content boilers. As such, any air entrainment within the system water will produce boiler “kettling”. It is therefore recommended, if in any doubt, to consider the use of sealed systems where possible.

2.7.2Sealed Systems

Sealed systems must be designed in accordance with BS 5449 and BS 7074 Pt1. A typical sealed system is shown in Figure 2.7.2. It must include :

(i)A safety valve fitted on the flow, adjacent to the boiler. It must be non adjustable and preset to 3 bar. A drain pipe must be attached, at least as

big as the valve connection, and routed to drain in any area not hazardous nor where it may be subject to freezing.

(ii)An expansion vessel complying with BS 4814 and sized in accordance with the requirements of BS 5449 and BS 7074 Pt 1. The vessel must be positioned on the primary return to the boiler. Table 2.7.2 Expansion Vessel Selection provides guidance for the correct expansion vessel size to use.

(iii)A filling point, in accordance with local water authority requirements.

(iv)A method of system make-up (automatic or manual), in accordance with local water authority requirements.

(v)There must be no permanent connection of mains water to the boiler system.

(vi)The installation must be designed to work with flow temperatures of up to 110 oC.

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WD536	Chapter 2 - Boiler Location The Keston C45, C40P, C55 & C55P

Air Vent

Hose Union bib tap

C45 or

C55	Expansion
		L/S
	Vessel		Double Check
		RETURN	Valve
	By-pass
	Bal.	HEATING CIRCUIT	Hosepipe
	Valve
Drain		FLOW	( disconnected
			after filling )
Cock	Safety
	Valve
		BS 1010:2	Hose
			Connector
		Stop Tap
	Test Cock
	Figure 2.7.2 : Sealed System Diagram

All components of the system including the heat exchanger of the indirect cylinder must be suitable for a working pressure of 3 bar and a temperature of 110 oC. Care should be taken in making all connections that the risk of leakage is minimised.

Safety Valve Setting	3.0 bar
Vessel charge & initial system	0.5 bar	1.0 bar	1.5 bar
pressure.
Total Water Content of system	Expansion	Vessel	Volume
25 litres	2.1	2.7	3.9
50 litres	4.2	5.4	7.8
75 litres	6.3	8.2	11.7
100 litres	8.3	10.9	15.6
125 litres	10.4	13.6	19.5
150 litres	12.5	16.3	23.4
175 litres	14.6	19.1	27.3
200 litres	16.7	21.8	31.2
225 litres	18.7	24.5	35.1
250 litres	20.8	27.2	39.0
275 litres	22.9	30.0	42.9
300 litres	25.0	32.7	46.8
Multiplying factor for other system	0.0833	0.109	0.156
volumes
Table 2.7.2 Expansion Vessel Selection

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