Saunier Duval Ecosy 2 28E Installation, Use and Servicing Instruction

Instructions for Use

Installation and Servicing

Ecosy 2

28E

G.C. No. 47-920-29

221874A.03.01

T o be left with the user

9221

Condensing

Combination Boiler

This is a Cat I2H Appliance

Reference in these instructions to British Standards and Statutory

Regulations/Requirements apply only to the United Kingdom.

The instructions consist of three parts, User, Installation and Servicing Instructions, which includes the Guarantee Registration

For Ireland the rules in force must be used.

Card. The instructions are an integral part of the appliance and must, to comply with the current issue of the Gas Safety

(Installation and Use) Regulations, be handed to the user on completion of the installation.

Guarantee Registration

Thank you for installing a new Saunier Duval appliance in your home.

Saunier Duval appliances are manufactured to the very highest standard so we are pleased

to offer our customers a Comprehensive First Year Guarantee.

In the centre pages are to be found your Guarantee Registration Card, which we recommend you complete and

return as soon as possible.

If this card is missing you can obtain a copy or record your registration by telephoning the Heatcall Customer

Service number 01773 828100.

Our Guarantee gives you peace of mind plus valuable protection against breakdown by covering the cost of:

✔

All replacement parts

❏

✔

All labour charges

❏

All call-out charges

✔

❏

One Contact Local Service

FOR 1ST YEAR GUARANTEE PROTECTION

CALL 0208 247 9857

Customer Services: Tel: (01773) 828100 Fax: (01773) 828070

Nottingham Road, Belper, Derbyshire. DE56 1JT

Tel: (01773) 824141 Fax: (01773) 820569

Hepworth Heating Ltd.,

General/Sales enquiries:

Contents

CONTENTS DESCRIPTION SECTION PAGE No.

INSTRUCTIONS

FOR USE

Introduction 3 Operating the Boiler 3 Clock Setting 5

General Information 1 6

INSTALLATION

INSTRUCTIONS

Boiler Position 2 8 Flue Location and Ventilation 3 9 Heating System 4 11 Domestic Hot Water System 5 13 Installation Preparation 6 13 Flue Preparation 7 15 Boiler Fixing 8 17 Gas, Water and Condensate Conns. 9 17 Electrical Connections 10 18 Commissioning 11 20

SERVICING

INSTRUCTIONS

Servicing 12 25 Fault Finding 13 29 Replacement Parts 14 32

Important Information

General

The Ecosy 2 28E can provide room heating as part of a central heating system, and domestic hot water direct from the cold water supply. Instantaneous domestic hot water is available from a small integral hot water storage vessel, so additional secondary storage is not required. The central heating water temperature and domestic hot water temperature can both be adjusted on the boiler.

Once the controls are set the boiler operates automatically. When there is no heating or hot water demand the burner may operate very occasionally to maintain the temperature of the hot water in the storage vessel at the required level. If there is no heating demand for 24 hours then the pump and 3-way valve will be operated to prevent them sticking. A frost protection program is also included.

Please read these instructions and follow them carefully for the safe and economical use of your boiler.

Gas Category

This boiler is for use only on G20 gas.

Gas Safety (Installation and Use) Regulations

In your own interests and that of safety, it is the Law that ALL gas appliances are installed by a competent person in accordance with the current issue of the above regulations.

Gas Testing and Certification

The boiler is tested and certificated for safety and performance. It is, therefore, important that no alteration is made to the boiler unless approved, in writing, by Hepworth Heating Ltd.

Any alteration not approved by Hepworth Heating Ltd., could invalidate the certification, boiler warranty and may also infringe the current issue of the Statutory requirements.

Spare Parts

When replacing a 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 Hepworth Heating Ltd.

CE Mark

This boiler meets the requirements of Statutory Instrument, No. 3083 The Boiler Efficiency Regulations, and therefore is deemed to meet the requirements of Directive 92/42/EEC on the efficiency requirements for new hot water boilers fired with liquid or gaseous fuels.

Type test for purposes of Regulation 5 certified by:

Notified body 0063.

Product/production certified:

Notified body 0063.

The CE Mark on this appliance shows compliance with:

1. Directive 90/396/EEC on the approximation of the Laws of the Member States relating to appliances burning gaseous fuels.

2. Directive 73/23/EEC on the harmonization of the Laws of the Member States relating to electrical equipment designed for use within certain voltage limits.

3. Directive 89/336/EEC on the approximation of the Laws of the Members States relating to electromagnetic compatibility.

Control of Substances Hazardous to Health

Under Section 6 of The Health and Safety at Work Act 1974, we are required to provide information on substances hazardous to health.

The adhesives and sealants used in this appliance are cured and give no known hazard in this state.

221874A

Important Information

Insulation Pads/Ceramic Fibre, Glass yarn

These can cause irritation to skin, eyes and the respiratory tract. If you have a history of skin complaint you may be susceptible

to irritation. High dust levels are usual only if the material is broken.

Instructions for Use

Gas Leak or Fault

If a gas leak or fault exists or is suspected, turn the boiler mains electrical supply off and turn off the gas supply at the meter. Consult your local gas company or your local installation/ servicing company.

Electrical Supply Failure

The boiler will not work without an electrical supply. Normal operation of the boiler should resume when the electrical

supply is restored. If not, the boiler safety cut-off may have operated, please refer to the following section to reset.

Reset any external controls, to resume normal operation of the central heating.

The digital timer, if fitted, has a lithium battery back up and will not need resetting.

Normal handling should not cause discomfort, but follow normal good hygiene and wash your hands before eating, drinking or going to the lavatory.

If you do suffer irritation to the eyes or severe irritation to the skin seek medical attention.

Reset Button

Refer to diagram 1 which shows the fascia behind the drop down door.

If the burner goes out check the digital display. Flashing digits on the display indicate a fault. Allow the boiler to cool down for at least four minutes then press the ‘reset’ button. This should restart the boiler.

To obtain service call your installer or Heatcall (Saunier Duval's own service organisation) using the telephone number given on the front page of these instructions.

Dripping taps

If a hot water tap is dripping there is a possibility that the boiler will not supply central heating when there is a demand. This will occur when the boiler controller can detect a flow in the domestic hot water circuit. It will continue to supply hot water until the flow is no longer detected. To solve this problem either turn off the dripping tap or replace the tap seal as required.

Operating the Boiler

FASCIA

RESET BUTTON

To Operate the Boiler

1. Check that all five isolating valves are open with their slots in line with the length of the valve, see diagram 8.1.

2. A sealed pressurised system must be filled and

pressurised by a competent person.

Only operate the boiler when you are sure that the system has been filled and pressurised. Check this by looking at the pressure gauge which should read a minimum of 1.0bar, see diagram 1.

DIGITAL DISPLAY

MODE

BUTTON

PRESSURE GAUGE

Diagram 1

3. Open a hot water tap, check that water flows, then close it.

4. If you are in any doubt about the boiler being filled with water contact your installation/servicing company or the local gas company.

5. Check that the electrical supply to the boiler is ON at the external isolator.

6. Set clock/timer (if fitted) and any remote controls as required.

7. If the display is flashing, press the 'reset' button, shown on diagram 1.

8. The boiler should now operate.

9232

3 221874A

Operating the Boiler

User Controls

The boiler is factory preset to supply domestic hot water up to

C and central heating up to 70oC.

65 The operation of the boiler can be altered by using the ‘mode’

button. Temperature Selection and Control Options are detailed in sections 11.8 to 11.11.

Additional Options

Other modes are available by repeatedly pressing the ‘mode’ button. These cover fault indication and servicing and should only be accessed by the service engineer. Repeated pressing of the ‘mode’ button will eventually return the display to show boiler temperature, see diagram 11.4.

To Turn the Boiler Off

It is preferable to leave the electrical supply on whenever possible to permit operation of the built-in frost protection (see ‘Protection Against Freezing’ below) and daily pump and valve exercise.

To turn off the central heating use the room thermostat or clock/ timer.

To turn off the domestic hot water select

Options in section 11.8 and diagram 11.4). For holiday mode, refer to section 11.8. To turn off the boiler for servicing, isolate it from the electrical

supply. To turn it on again follow the instructions given in ‘To Operate the Boiler’.

(see Control

Maintenance and Servicing

If this appliance is installed in a rented property there is a duty of care imposed on the owner of the property by the current issue of the Gas Safety (Installation and Use) Regulations, Section 35.

Servicing/maintenance should be carried out by a competent person in accordance with the rules in force in the countries of destination.

To obtain service, please call your installer or Heatcall (Saunier Duval’s own service organisation) using the telephone number on the front cover of this booklet.

Please be advised that the ‘Benchmark’ logbook should be completed by the installation engineer on completion of commissioning and servicing.

All CORGI Registered Installers carry a CORGI ID card, and have a registration number. Both should be recorded in your boiler Logbook. You can check your installer is CORGI registered by calling CORGI direct on :- 01256 372300.

If in doubt, contact you installation/servicing company for advice. As a safety feature the boiler will stop working if the condensate

drain becomes blocked. The display will repeatedly flash ‘

‘8*’. During freezing conditions this may be due to the

then forming of ice in the condense drain external to the house. Release an ice blockage by the use of warm cloths on the pipe. Press the reset button to restart the boiler. Contact your installation / servicing company if the fault persists.

Draining and Filling

This boiler works in a pressurised system which must only be drained, refilled and pressurised by a competent person.

If the pressure gauge indicates a loss of system pressure, i.e. less than 0.7bar, the appliance will shut down showing flashing:

‘1’ then ‘2*’ on the display. YOU MUST CONTACT YOUR

INSTALLER.

Pressure Relief Safety Valve

A pressure relief safety valve and discharge pipe is fitted to the boiler. This valve must not be touched. Should there be

any discharge from the pipe, isolate the boiler electrical supply and contact your installation/servicing company.

Cleaning

This appliance contains metal parts and care should be taken when handling and cleaning with particular regard to edges.

The boiler casing can be cleaned using a mild liquid detergent with a damp cloth, then a dry cloth to polish.

Do not use any form of abrasive or solvent cleaner as you may damage the paint work.

Boiler Casing

Do not remove or adjust the casing in any way, as incorrect fitting may result in incorrect operation or failure to operate at all. If in doubt seek advice from the local gas company or your

installation/servicing company.

Replacement Parts

If replacement parts are required apply to your local supplier or British Gas.

Please quote the name of the appliance.

Pluming from flue terminal

All condensing boilers produce a plume of water vapour from the flue terminal. This is due to the high efficiency and hence low flue gas temperature. This may increase in wet, damp weather but is nothing to worry about.

0’

Clearances

If the boiler is fitted into a compartment or cupboard do not use the compartment or cupboard for storage.

Protection Against Freezing

The boiler has a built in frost protection programme as long as the electricity and gas are left switched on.

This device only protects the boiler. Any other exposed areas of the system should be protected.

If the mains electricity and gas are to be turned off for any long periods during severe weather, it is recommended that the whole system, including the combination boiler, should be drained to avoid the risk of freezing.

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Clock Setting

Setting Instructions for Electro/mechanical Clock - if fitted

Refer to diagram 2. This clock has a twenty four hour dial, i.e. 1pm is '13'. To set the time, turn the whole face clockwise until the pointer

is against the time of day. To set any “Off” time, push the tappets outwards. To set any “On” time, push the tappets inwards. Time can be set either “On” or “Off” in fifteen minute segments. Note: The clock supplied is fitted with an override device, which

switches the clock programme “On” or “Off” permanently.The switch will need to be repositioned to resume programmed working.

CLOCK FACE

OVERRIDE SWITCH

POINTER

TAPPETS

CONSTANT OFF PROGRAMMED

CONSTANT ON

Diagram 2

Setting Instructions for the 7 Day Digital Clock/Timer - if fitted

Refer to diagram 3.

5673

AUTO

WTh

DA Y HR MIN

RUN

This is a 24 hour clock/timer, that is 1pm is '13:00', and has 8 “ON” and 8 “OFF” daily switching actions.

It is fitted with a lithium battery back up which protects the programme in the event of an electrical failure. The battery should have a life of several years.

Setting the Clock

1. With both AUTO and RUN switches set to the central position, press R reset button, the display will flash.

2. Set RUN switch to .

3. Set day of week by pressing button DAY.

4. Set time of day by pressing buttons HR and MIN.

5. Set RUN switch to the central position, colon will flash, this indicates the clock is set.

With the clock set, the factory preset programme shown below will operate.

4956

MON/FRI

ON - 06:30 OFF - 08:30 ON - 16:30 OFF - 22:30

SAT/SUN

ON - 07:00 OFF - 09:00 ON - 16:00 OFF - 23:00

Setting Timed Programmes

With the clock set to the correct time, see SETTING THE CLOCK paragraphs 1-4, and then continue as follows:

1. Set RUN switch to P , the display will indicate the 1st (ON) preset programme and the symbol

2. Set day of week to be programmed by pressing the DAY button.

Note. The days can be selected individually or as groups:

Mon-Fri., Mon-Sat., Mon-Sun., Sat/Sun. An arrow will be displayed under the day or

days selected.

3. Set time of day by pressing the buttons HR and MIN.

4. Press button P to confirm programmes, the display will indicate the 2nd (OFF) preset

programme andsubsequently, 3rd, 4th, 5th, 6th. 7th, 8th to 16th.

5. Repeat procedures 2, 3 and 4 until desired programmes are set.

Note. It is not a requirement to use all of the 8 on and 8 off programmes.

6. Set the RUN switch the central position, your appliance will now operate at the programmed times.

General Notes: With the AUTO switch in the I position the central heating will

operated constantly ON. With the AUTO switch in the O position the central heating will

not operate. Soft Override button indicated by the symbol

function will override the current central heating programme for the next available.

ON time programmes are indicated by the symbol

, this

Diagram 3

5 221874A

145

1 Installation Instructions

373

208

520

9053

101

CONDENSATE SIPHON

Condensate Drain Connection

140

INSIDE WALL FIXING FACE

140

CAP

1.1 Installation

Where no British Standards exists, materials and equipment should be fit for their purpose and of suitable quality and workmanship.

When installing the appliance, care should be taken to avoid any possibility of personal injury when handling sheet metal parts.

The installation of this boiler must be carried out by a competent person in accordance the rules in force in the countries of destination.

Manufacturer’s instructions must not be taken as overriding statutory requirements.

1.2 Gas Supply

This boiler is for use only on G20 natural gas. The gas installation must be in accordance with the current

issue of BS6891. The supply from the governed meter must be of adequate size

to provide a steady inlet working pressure of 20mbar (8in wg) at the boiler.

On completion, test the gas installation for soundness using the pressure drop method and suitable leak detection fluid, purge in accordance with the above standard.

1.3 Data Label

The data label is on the base panel inside the appliance.

1.4 Electrical Supply

The boiler must be earthed.

All system components shall be of an approved type and all wiring to current I.E.E. wiring regulations.

The boiler must be connected to a permanent 230V ac, 50Hz supply.

Connection of the whole electrical system of the boiler, including any heating controls, to the electrical supply must be through one common isolator.

Isolation should be by a double pole switched fused spur box, with a minimum gap of 3mm for both poles. The fused spur box should be readily accessible and preferably adjacent to the appliance. It should be identified as to its use.

118

890

BOILER

REFER TO THE WALL TEMPLATE FOR PIPE DIMENSIONS

Diagram 1.1

Alternatively connection can be made through an unswitched shuttered socket and 3A fused 3 pin plug.

The mains supply cable and other cables connected to the boiler must be the PVC flexible type of at least 0.75mm

0.20mm).

The colours of three core flexible cable are, blue - neutral, brown - live, green and yellow - earth.

The wire coloured blue must be connected to the terminal marked “N” or “Black”.

The wire coloured brown must be connected to the terminal marked “L” or “Red”.

The wire coloured green and yellow must be connected to the terminal marked “E” or “Green” or the earth symbol

(24/

1.5 Condensate Drain

A plastic drain pipe must be fitted to allow discharge of condensate to a drain.

Condensate should, if possible, be discharged into the internal household draining system. If this is not practical, discharge can be made externally into the household drainage system or a purpose designed soak away, see section 9.4 for more details.

1.6 Boiler Efficiency

The Seasonal Efficiency Domestic Boilers UK (SEDBUK) is: Ecosy 2 28E: 90.1% 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 has been certified by Gastec.

221874A

1 General Information

TABLE 1 C.H. Max D.H.W.Max MIN

9055

NOMINAL HEAT INPUT kW 32.5 32.5 11.7 GROSS Btu/h 110,890 110,890 39,920

NOMINAL HEAT OUTPUT kW Btu/h 97,583 97,583 34,120

COND. HEAT OUTPUT kW 30.0 30.0 11.3

Btu/h 102,360 102,360 38,556

BURNER MANIFOLD SUCTION PRESSURE HOT(APPROX)

mbar

wg -1.92 -1.92 -0.2

28.6 28.6 10.0

-4.8 -4.8 -0.5

SCHEMATIC LAYOUT OF BOILER

Diagram 1.2

TABLE 2

Lift Weight 64kg (141lb) Total Weight (packed) 68kg (150lb) Total Weight (installed) 86kg (189lb)

● Gas connection Rc1/2 (1/2in BSPT)

● Heating and return 22mm compression

● Domestic hot water 15mm compression

Safety valve Preset 3bar (43.5lbf/in

Safety valve discharge 15mm copper

BURNER %CO

CASING

DOOR ON

CASING DOOR OFF

9.2-9.6 9.2-9.6 9.2-9.6

9.0-9.4 9.0-9.4 9.0-9.4

APPROX. GAS RATE

m3/h

2.9 2.9 1.0

ft3/h 102.4 102.4 35.3

Domestic hot water flow rate

temp rise 300C 13.3l/min (2.9gall/min)

350C 11.4l/min (2.5gall/min)

Maximum flow temperature 650C Minimum working pressure 0.1bar

■ Maximum heating 130 litres

system water (28.6 gallons)

content using at 75

)

fitted expansion average system

vessel, pressurised temperature at 1bar.

Water content (heat exch) 2.7 ltr (0.59 gall) Water content (primary store) 12.4 ltr (2.7 gall) Water content (domestic) 2 ltr (0.44 gall)

■ Expansion vessel capacity 7 litres (1.54 gallons) Charge pressure 0.5bar (7.3lbf/in Heating system 0.7bar (10.1lbf/in

)

minimum pressure

D.H.W Max. 8bar working pressure (150lbf/in2)

Electrical supply 230V~50Hz

Electrical rating 115W fused 3A

IP classification IP40 Internal Fuse rating 1) Type 2AF

2) Type 2AF

3) Type 3AT

● Ball valves are fitted in water and gas connections, plus a drain point on all water connections.

■ For larger systems use an additional expansion vessel.

7 221874A

2 Boiler Position

2.1 Location

The boiler is not suitable for fitting outdoors. Any electrical switch or boiler control using mains electricity

must be positioned so that it cannot be touched by a person using a bath or shower.

The boiler must be mounted on a flat wall which is sufficiently robust to take its weight, refer to Table 2.

2.2 Clearances

The boiler should be positioned so that at least the minimum operational and servicing clearances are provided, see diagram

2.1. Additional clearances may be beneficial around the boiler for

installation and servicing. For flue installations where external access is not practicable,

consideration should be given for the space required to insert the flue internally which may necessitate clearance larger than those specified in diagram 2.1.

9070

† 600

200

Increase to 25mm clearance from combustible material.

† A removable compartment door can be placed at least 5mm in front of the appliance.

Dimensions in millimetres

MINIMUM CLEARANCE FROM PERMANENT SURFACES

200

Diagram 2.1

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3 Flue Location and Ventilation

3.1 Flue Position and Length

There are several flueing options available for the Ecosy 2 28E, e.g. horizontal, vertical and twin flue.

The standard horizontal flue is fitted onto the top of the boiler using the flue elbow.

See diagrams 3.1 to 3.3 to determine whether a standard flue can be used.

The standard flue can be extended using 1m long extension kits and 90° elbows. A maximum of 3500mm of extension pipes plus 3x90° bends can be added to the standard horizontal flue length.

When extension pipes are used the flue system must be designed to have a continuous fall to the boiler of at least 2.5° to allow condensate to run back into the boiler and out via the drain.

3.2 Internal Flue Installation

The flue can be installed from inside the building, when access to the outside wall face is not practicable.

3.3 Terminal Position

The minimum acceptable siting dimensions for the terminal from obstructions, other terminals and ventilation openings are shown in diagram 3.4.

The terminal must be exposed to the external air, allowing free passage of air across it at all times.

Being a condensing boiler some pluming may occur from the flue outlet. This should be taken into consideration when selecting the position for the terminal.

Car ports or similar extensions of a roof only, or a roof and one wall, require special consideration with respect to any openings, doors, vents or windows under the roof. Care is required to protect the roof if made of plastic sheeting. If the car port comprises of a roof and two or more walls, seek advice from the local gas supply company before installing the boiler.

If the terminal is fitted less than 600mm below plastic guttering or less than 450mm below painted eaves or a painted gutter, an aluminium shield 750mm long should be fitted immediately beneath the guttering or eaves.

WALL THICKNESS 'X' = 75 TO 554mm

"X"

REAR FLUE - STANDARD

DISTANCE 'Y' = 307 TO 755mm

Diagram 3.1

6501

6502

DISTANCE 'Y' = 393 TO 755mm

6503

"Y"

SIDE FLUE - STANDARD Left

Diagram 3.2

"Y"

SIDE FLUE - STANDARD Right

9 221874A

Diagram 3.3

3 Flue Location and Ventilation

B,C

UNDER CAR PORT etc.

H,I

3.4 Terminal Guard

A terminal guard is required if persons could come into contact with the terminal or the terminal could be subject to damage.

If a terminal guard is required, it must be positioned to provide minimum of 50mm clearance from any part of the terminal and be central over the terminal.

The guard should be similar to that shown in diagram 3.5. A suitable guard can be obtained from. Tower Flue Components Morley Rd. Tonbridge Kent TN9 1RA. Their Reference CGD K3 BL.

3.5 Timber Frame Buildings

If the boiler is to be installed in a timber frame building it should be fitted in accordance with the Institute of Gas Engineers document IGE/UP/7/1998. If in doubt seek advice from the local gas undertaking or Hepworth Heating Ltd.

3.6 Room Ventilation

The boiler is room sealed, so when it is installed in a room or space, a permanent air vent is not required.

3.7 Cupboard or Compartment Ventilation

Due to the high efficiency and hence low casing temperature of this boiler, cupboard or compartment ventilation is not necessary.

TERMINAL GUARD

Diagram 3.5

MINIMUM SITING DIMENSIONS FOR FANNED FLUE TERMINALS POSITION

MM A DIRECTLY BELOW, ABOVE OR

HORIZONTALLY TO AN OPENING, AIR BRICK, OPENING WINDOWS, AIR VENT

OR ANY OTHER VENTILATION OPENING

300 B BELOW GUTTER, DRAIN/SOIL PIPE 75 C BELOW EAVES 200 D BELOW A BALCONY OR CAR PORT 200 E FROM VERTICAL DRAIN PIPES AND

SOIL PIPES 75

F FROM INTERNAL CORNERS 300* G ABOVE ADJACENT GROUND OR

BALCONY LEVEL 300

H FROM SURFACE FACING THE

TERMINAL 600*

I FACING TERMINALS 1200 J FROM OPENING (DOOR/WINDOW)

IN CAR PORT INTO DWELLING 1200 K VERTICAL FROM A TERMINAL 1500 L HORIZONTALLY FROM A TERMINAL 300 M FROM EXTERNAL CORNERS 300

Diagram 3.4

2816

221874A

* It may be necessary to increase this dimension to prevent

staining of adjacent walls depending on weather conditions.

4 Heating System

4.1 General

The boiler is for use only with sealed central heating systems. The safety valve is an integral part of the boiler and it cannot be

adjusted. A pressure gauge is incorporated on the boiler control panel to

indicate the system pressure. The circulation pump is integral with the boiler. The Ecosy 2

28E is fitted with a UPS 25-60 pump. A performance curve is shown in diagram 4.1.

4.2 Expansion Vessel

The boiler has an integral expansion vessel with a capacity of 7 litres (1.54 gallons), with a charge pressure of 0.5bar.

The maximum heating system water content using the fitted expansion vessel is 130 litres at an average temperature of 75OC, and charge pressure of 1.0bar.

4.3 Flow Rate

The minimum flow rate through the boiler is 1230 litres/hr. This is equal to 20

The system can be fitted with a lockable balancing valve if necessary in the main flow or return pipes shown as valve "A" in diagram 4.2.

C differential at maximum heat input.

4.4 Bypass

The boiler is fitted with a manual bypass, see diagram 4.3. This valve may be adjusted by the installer if necessary to ensure at least 1230 litres/hr flow through the boiler. The boiler is supplied with the bypass open by approximately half a turn and is closed by turning the white screw clockwise. However for systems completely fitted with thermostatic radiator valves or systems of high pressure loss an additional bypass valve must be fitted to the heating circuit to ensure that under no circumstances does the flow rate drop below this level.

An additional bypass valve “B” is shown in diagram 4.2.

4.5 Filling Sealed Systems

Provision for filling the system at a low level must be made. Two methods of filling are shown in diagram 4.4. There must be no permanent connection to the mains water supply, even through a non-return valve.

Diagram 4.1

9104

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