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 Ideal Boilers.
To obtain the gas consumption at a different calorific value:-
a. FOR L/S - divide the gross heat input (kW) by the gross
C.V. of the gas (MJ/m
b. FOR FT
C.V. of the gas (Btu/ft3)
3
/H - divide the gross heat input (Btu/h) by the gross
3
)
CAUTION.
appliance, care should be taken when handling edges of sheet steel components.
To avoid the possibility of injury during the installation, servicing or cleaning of this
2
Classic
FF
-
Installation & Servicing
GENERAL
Classic FF
Natural Gas only
Data Badge: on top of the controls support
B.G. Certified - P.I. No. 87AP107
Destination Countries: GB & IE
ModelsG.C. Appliance No.
Classic FF 330 ............ 41 391 54
Classic FF 340 ............ 41 391 95
Classic FF 350 ............ 41 391 96
Classic FF 360 ............ 41 391 97
Classic FF 370 ............ 41 391 98
Classic FF 380 ............ 41 391 99
Classic FF 3100 ........... 41 391 01
Appliance TypeBoiler size
C
12 & C32
C
C
72
12
FF 330, 340, 350, 370
FF 360 & 380 only
FF 3 100 only
Key to symbols
IE= Ireland
GB= United Kingdom
PMS = Maximum operating pressure of water
& C32 =A room sealed appliance designed for
C
12
connection via ducts to a horizontal or vertical terminal,
which admits fresh air to the burner and discharges
the products of combustion to the outside through
orifices which, in this case, are concentric. The fan is
down stream of the combustion chamber.
C72 = A room sealed appliance designed for connection via
concentric vertical ducts and a draught diverter located
in the roof space to a secondary flue. The combustion
air is taken from the roof space. The fan is down
stream of the combustion chamber.
I
= An appliance designed for use on 2nd Family gas,
2H
Group H only.
CONTENTS
Air Supply. ..................................................................... 6
Water and Systems ..................................................... 7
Water Treatment ..........................................................7
For GB, to comply with Building Regulations Part L1 (Part J in Scotland) the boiler should be fitted in accordance with the
manufacturer's instructions. Self-certification that the boiler has been installed to comply with Building Regulations can be
demonstrated by completing and signing the Benchmark log book.
BENCHMARK LOG BOOK DETAILS
BoilerPage
Make and model .......................................................3
Appliance serial no. on data badge ........................ 11
For assistance see Technical Helpline on the back page
complete, sign & hand over to customer
Page
3
GENERAL
INTRODUCTION
The Classic FF330-3100 is a range of automatically fully controlled,
wall mounted, balanced flue, fanned gas boilers.
The heat exchanger is cast iron. The boiler casing is of white
enamelled mild steel.
The boiler casing has a removable controls pod containing a drop-
down door. The boiler thermostat is located behind the drop- down
door.
These boilers cannot be used on systems which include
Note.
gravity circulation.
range of boilers is suitable.
See Frame 1 for details of the correct boiler tappings to use.
The boilers are supplied with a standard flue kit suitable for rear or
side outlet applications from 114 mm (4 1/2") to 600 mm
(23 1/2").
The boilers are suitable for connection to the following open
vented or sealed systems:
Sealed System Unit* - this fits on top of the appliance.
Extension ducts * - up to 3m (118").
Turret Outlet Kit.*
*
not available for FF3 100
CURRENT GAS SAFETY (INSTALLATION AND USE)
REGULATIONS OR RULES IN FORCE.
The appliance is suitable only for installation in GB and IE and
should be installed in accordance with the rules in force.
In GB, the installation must be carried out by a CORGI
Registered Installer. It must be carried out in accordance with
the relevant requirements of the:
•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 Competent
Person and installed in accordance with the current edition of
I.S.813 "Domestic Gas Installations", the current Building
Regulations and reference should be made to the current ETCI
rules for electrical installation.
Detailed recommendations are contained in the following British
Standard Codes of Practice:
BS.6891Low pressure installation pipes.
BS.6798Installation of gas fired hot water boilers of rated input
not exceeding 60 kW.
BS.5449Forced circulation hot water systems.
BS.5546Installation of gas hot water supplies for domestic
purposes (2nd Family Gases).
BS.7593Treatment of water in domestic hot water central
heating systems.
BS.5440.1 Flues for gas appliances of rated input not exceeding
60 kW.
BS.5440.2 Ventilation for gas appliances of rated input not
exceeding 60 kW.
Health & Safety Document No. 635
The Electricity at Work Regulations, 1989.
Manufacturer’s notes must NOT be taken in any way as overriding
statutory obligations.
IMPORTANT. These appliances are certificated by the British
Standards Institution 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
otherwise recommended by Caradon Ideal Limited in writing.
If in doubt please enquire.
Any direct reconnection of a control device not approved by CaradonIdeal Limited could invalidate the BSI Certification and the normal
appliance warranty. It could also infringe the Gas Safety Regulations
and the above regulations.
SAFE HANDLING OF SUBSTANCES
Care should be taken when handling the boiler insulation panels
which can cause irritation to the skin. No asbestos, mercury or
CFCs are included in any part of this boiler.
LOCATION OF BOILER
The boiler must be installed on a flat and vertical wall, capable of
adequately supporting the weight of the boiler and any ancillary
equipment.
The boiler may be fitted on a combustible wall and insulation
between the wall and the boiler is not necessary - unless required
by the local authority. The boiler must not be fitted outside.
Timber Framed Buildings
If the boiler is to be fitted in a timber framed building it should be
fitted in accordance with the Institute of Gas Engineering document
IGE/UP/7:1998.
Bathrooms
This range of appliances is rated IP 1XB.
The boiler may be installed in any room or internal space, although
particular attention is drawn to the requirements of the current
I.E.E. (BS.7671) Wiring Regulations and, in Scotland, the electrical
provisions of the building regulations applicable in Scotland with
respect to the installation of the boiler in a room or internal space
containing a bath or shower. For Ireland reference should be
made to the current ETCI rules for electrical installations and
I.S.813:2002.
.........continued on page 6
NOTE TO THE INSTALLER:
LEAVE THESE
INSTRUCTIONS ADJACENT TO THE GAS METER.
ALSO COMPLETE THE BENCHMARK LOG BOOK AND
GIVE THIS TO THE CUSTOMER.
4
Classic
FF
-
Installation & Servicing
1
BOILER WATER CONNECTIONS
This appliance in NOT suitable for use in a direct
hot water system or for gravity circulation.
FF 370, FF 380 & FF3 100 ONLY
must be fitted with the 22mm x 28mm copper sockets,
provided in the Hardware Pack, (or equivalent 22mm x
28mm compression fittings ) and the pumped flow and
return pipes run in 28mm pipe.
2
BOILER CLEARANCES
The following minimum clearances
must be maintained for operation and
servicing.
Additional space will be required for
installation, depending upon site
conditions.
Side and Rear Flue
a. Provided that the flue hole is cut
accurately, e.g. with a core drill, the
flue can be installed from inside the
building.
Installation from inside ONLY
b. If a core boring tool is to be used
inside the building; the space in
which the boiler is to be installed
must be at least wide enough to
accommodate the tool.
c. If using the Complete Sealed
System Unit then refer to the
instructions packed with the unit for
the necessary clearances.
Front ViewSide View
Pumped
flow pipe
12 (1/2")
141
(5 9/16")
700
(27 1/2")
Pumped
return
pipe
Gas
connection
380
(15")
300
(12")
GENERAL
44
(1 3/4")
Flue
terminal
100
(4")
Front clearance: 533mm (21")
from the front of the boiler
casing.
Minimum front clearance when
built in to cupboard is 75 mm
(3").
Pelmet restrictions.
If the ability to fit or remove the
casing during installation and
subsequent servicing is impaired
by pelmets etc. this operation can
be made easier by first removing
the controls pod casing in line
with the following instructions:
a. Release the controls pod
casing fixing screws (a) 3 full
turns only. Remove the pod by
pulling it forward to disengage
from the keyhole slots.
b. Undo the 2 screws (b)
retaining casing to the back
panel.
c. The casing can now be
removed in the direction of the
arrow, first lifting the casing
slightly to disengage the
casing top return from the
back panel. (For this purpose
a minimum clearance of
12mm is required between
the top of the boiler and
pelmet or other similar
obstruction.
20 (3/4")
Jacking
screw
Classic FF -
133 (5 1/4")
Installation & Servicing
Gas
connection
300 (12")
44 (1 3/4")
Clas 1783
5
GENERAL
If the appliance is to be installed in a room containing a bath or
shower then, providing waterjets are not going to be used for
cleaning purposes (such as communal baths/showers), the
appliance can be installed in Zone 3, as detailed in BS.7671.
Where installation will be in an unusual location, special
procedures may be necessary and BS.6798 gives detailed
guidance on this aspect.
Compartment Installations
A compartment used to enclose the boiler MUST be designed
and constructed specially for this purpose.
An existing cupboard or compartment may be used, provided it
is modified for the purpose.
In both cases details of essential features of cupboards/
compartment design, including airing cupboard installation, are
to conform to the following :
! BS. 6798.
! The position selected for installation MUST allow adequate
space for servicing in front of the boiler and for air circulation
around the boiler. Refer to 'Air Supply'.
! For the minimum clearances required for safety and
subsequent service refer to the wall mounting diagram,
Frame 2. In addition, sufficient space may be required to allow
lifting access to the wall mounting plate.
GAS SUPPLY
The local gas supplier should be consulted, at the installation
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 is to be installed only on a gas supply with a governed meter.
A gas meter can only be connected by the local gas supplier or by
a local regional contractor.
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. A MINIMUM pressure of 20 mbar MUST be
available at the boiler inlet with the boiler operating.
Installation pipes MUST be fitted in accordance with BS. 6891. In
IE refer to I.S. 813:2002. Pipework from the meter to the boiler
MUST be of an adequate size. FF3100 models should be piped in
22mm minimum. The final 1 metre may be run in 15mm if it is
visible.
The complete installation MUST be tested for gas soundness and
purged as described in the above code.
FLUE INSTALLATION
Pluming may occur at the terminal so terminal positions which
would cause a nuisance should be avoided.
The flue must be installed in accordance with the
recommendations of BS. 5440-1:2000. In IE refer to I.S. 813:2002.
The following notes are intended for general guidance:-
1. The boiler MUST be installed so that the terminal is exposed
to external air.
2. It is important that the position of the terminal allows the free
passage of air across it at all times.
3. Minimum acceptable spacing from the terminal to obstructions
and ventilation openings are specified in Table 3.
4. Where the lowest part of the terminal is fitted less than 2m
(6'6") above a balcony, above ground or above a flat roof to
which people have access then the terminal MUST be protected
by a purpose designed guard. The minimum spacing in Table 3,
Nos. 2,3, 4, 5 and 6 would be 75mm in order to allow a terminal
guard to be fitted.
Terminals guards are available from boiler suppliers - ask for
TFC Flue Guard, Model K1. In case of difficulty seek advice
from:
Table 3 - Balanced flue terminal position
Approved Manufacturer’s Clearances
Terminal PositionMinimum Spacing
1a. Directly BELOW an opening, air brick,
opening window, etc.300 mm (12")
1b. Directly ABOVE an opening, air brick,
opening window, etc.300 mm (12")
1c. HORIZONTALLY to an opening,
air brick, opening window, etc.300 mm (12")
2. Below guttering, drain pipes or soil pipes25 mm ( 1")
3. Below eaves25 mm ( 1")
4. Below balconies or a car port roof25 mm ( 1")
5. From vertical drain pipes or soil pipes25 mm ( 1")
6. From an internal or external corner or
to a boundary alongside the terminal25 mm ( 1")
7. Above adjacent ground, roof or
balcony level300 mm (12")
8. From a surface or a boundary
facing the terminal600 mm (24")
9. From a terminal facing a terminal1200 mm (48")
10. From an opening in a car port
(e.g. door or window) into dwelling1200 mm (48")
11. Vertically from a terminal on the
same wall1500 mm (60")
12. Horizontally from a terminal on the wall300 mm (12")
5. The flue assembly shall be so placed or shielded as to prevent
ignition or damage to any part of any building.
6. The air inlet/products outlet duct and the terminal of the boiler
MUST NOT be closer than 25mm (1") to combustible material.
Detailed recommendations on the protection of combustible
material are given in BS.5440-1:2000. In IE refer to I.S.
813:2002.
7. Where it is essential that the terminal wall plate is fitted, i.e.
wall thicknesses over 600mm (23
cut hole, the minimum spacing in Table 3 Nos. 2,3, 4, 5 and 6
would be 60mm (2 1/2") in order to allow the terminal wall plate
to be fitted.
IMPORTANT. It is absolutely ESSENTIAL to ensure, in practice, that
products of combustion discharging from the terminal cannot reenter the building or any other adjacent building through ventilators,
windows, doors, other sources of natural air infiltration, or forced
ventilation/air conditioning.
If this should occur, the appliance MUST be turned OFF, labelled
'unsafe' and corrective action taken.
1/2") or with an inaccurately
TERMINAL
The terminal assembly can be adapted to accommodate various
wall thicknesses. Refer to Frame 10.
AIR SUPPLY
Detailed recommendations for air supply are given in BS.5440:2.
In IE refer to I.S. 813:2002.
The following notes are for general guidance:
1. It is NOT necessary to have a purpose provided air vent in the
room or internal space in which the boiler is installed.
6
Classic
FF
-
Installation & Servicing
GENERAL
2. If the boiler is to be installed in a cupboard or compartment,
permanent air vents are required (for cooling purposes) in
the cupboard/compartment, at both high and low levels.
The air vents must either communicate with room/internal
space, or be direct to outside air. The minimum effective
areas of the permanent air vents, required in the cupboard/
compartment, are specified in Table 4 and are related to
maximum rated heat input.
3. Both air vents MUST communicate with the same room or
internal space or MUST be on the same wall to outside air.
4. In siting the air vents care must be taken to avoid the
The boiler must NOT be used for direct hot water supply. For the
types of system and correct piping procedure refer to 'Introduction'
and Frame 1.
The central heating system should be in accordance with BS.6798
and, in addition, for Smallbore and Microbore systems, BS. 5449.
The domestic hot water system, if applicable, should be in
accordance with the relevant recommendations of BS. 5546. Copper
tubing to BS. 2871:1 is recommended for water carrying pipework.
The hot water storage cylinder MUST be of the indirect type and
should preferably be manufactured of copper.
Single feed, indirect cylinders are not recommended and MUST
NOT be used on sealed systems.
The appliances are NOT suitable for gravity central heating, nor
are they suitable for the provision of gravity domestic hot water.
The hot water cylinder and ancillary pipework, not forming part of
the useful heating surface, should be lagged to prevent heat loss
and any possible freezing - particularly where pipes run through
roof spaces and ventilated under floor spaces.
Boilers not fitted to a sealed system must be vented.
IMPORTANT
A minimum length of 1m of copper pipe MUST be fitted to both
flow and return connections from the boiler before connection to
any plastic piping. This applies to ALL types of installation.
Draining taps MUST be located in accessible positions, which
permit the draining of the whole system - including the boiler
and hot water storage vessel. They should be at least
nominal size and be in accordance with BS. 2879.
The boiler is fitted with a special drain plug, which is provided, to
drain the BOILER ONLY, in the event of the system drain plug
being unable to do so. The hydraulic resistance of the boilers, at
MAXIMUM OUTPUT with an 11
are shown in Table 5.
Maximum boiler operating temperature should be 82 oC (180 oF).
These boilers incorporate a cast iron heat exchanger.
IMPORTANT. The application of any other treatment to this
product may render the guarantee of Caradon Ideal Limited
INVALID.
Caradon Ideal Limited recommend Water Treatment in
accordance with the
Treatment in Central Heating Systems.
Caradon Ideal Limited recommend the use of Fernox, GE Betz
Sentinel or Salamander water treatment products, which must
be used on accordance with the manufacturers instructions.
For further information contact:
Fernox Manufacturing Co. Ltd, Cookson Electronics, Forsyth Road,
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.
BS7593:1992 details the steps necessary to clean a
domestic heating system.
3. In hard water areas, treatment to prevent limescale 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.
BOILER CONTROL INTERLOCKS
Caradon Ideal Limited recommend that heating systems utilising
full thermostatic radiator valve control of temperature in individual
rooms should also be fitted with a room thermostat controlling the
temperature in a space served by radiators not fitted with such a
valve as stated in BS. 5449.
Central heating systems controls should be installed to ensure the
boiler is switched off when there is no demand for heating or hot water.
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 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 without end switches, 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.
Benchmark
Guidance Notes on Water
Classic FF -
Installation & Servicing
7
GENERAL
ELECTRICAL SUPPLY
WARNING.
Wiring external to the appliance MUST be in accordance with the
current I.E.E. (BS.7671) Wiring Regulations and any local
regulations which apply. For Ireland reference should be made
to the current ETCI rules for electrical installations.
The point of connection to the mains should be readily accessible
and adjacent to the boiler, except that for bathroom installations;
the point of connection to the mains MUST be situated outside of
the bathroom.
3
The system should be vented directly off the boiler flow pipe, as
close to the boiler as possible. The cold feed entry should be
inverted and MUST be positioned between the pump and the vent,
and not more than 150mm (6") away from the vent connection.
There should be a minimum height - 450mm (18") - of open vent
above cistern water level. If this is impossible refer below.
The vertical distance between the highest point of the system and
the feed/expansion cistern water level MUST not be less than
450mm (18").
The pump MUST be fitted on the flow side of the boiler.
A suitable pump is a domestic circulator capable of providing an
11°C (20°F) temperature differential (e.g. Grundfos UPS 15/50 or
equivalent). The vertical distance between the pump and feed/
expansion cistern MUST comply with the pump manufacturers
minimum requirements to avoid cavitation. Should these
conditions not apply, either lower the pump position or raise the
cistern above the minimum requirement specified by Caradon
Ideal Limited.
Note.
all automatic valves are in the closed position (refer to BS. 6798)
and when close coupled the feed must not be in a vertical leg.
The appliance MUST be efficiently earthed.
OPEN VENT SYSTEM REQUIREMENTS - FULLY PUMPED
A cold water feed must be available back to the boiler, when
Note.
Where a room sealed appliance is installed in a room containing a
bath or shower then the appliance and any electrical switch or
appliance control utilising mains electricity should be so situated
that it cannot be touched by a person using the bath or shower.
See Frame 38 for details.
Feed / expansion
cistern
Water
level
(cold)
22mm
Open vent
System
return
Connections
to boiler
15mm
Cold
feed
Inverted cold
feed entry
450 (18")
Mimimum
450 (18")
Mimimum
150 (6")
Max
System
flow to
pump
4
LOW HEAD INSTALLATIONS
The Classic range of boilers can be installed in
low head situations by fitting a 'surge arrester' in
the expansion pipe as shown.
The following conditions MUST be observed:
1. The surge arrester must be at least 42mm in
diameter x 150mm long, thus ensuring a
MINIMUM air gap and a MINIMUM depth of
water below the static water level (cold) of
75mm.
2. The static water level (cold) must be at least
200mm above the top of the horizontal flow
pipe, fitted as shown. The vent connection
MUST NOT be made immediately off the top of
the boiler, as venting is made less efficient.
3. The maximum practical length of 15mm cold
feed pipe should be used in order to reduce
the effective volume of system water
expanding into the feed/expansion cistern to a
minimum.
The pump manufacturers minimum
Note.
requirements must be complied with.
8
75 (3)
Min.
450
(18)
Min.
Return
All dimensions in mm (in.). N.B.
200
(8)
Min.
75 (3) Min.
Minimum Requirements
Feed / expansion
Surge
arrester
22 (3/4)
Flow
Highest
point of
flow or
return
Open vent
150
(6)
Max
Imperial dimensions are approximate
Classic
FF
Cold
cistern
Max. practical
length
-
Installation & Servicing
water
level
To pump
5
SEALED SYSTEM REQUIREMENTS
ecl6060
GENERAL
Hose unions
Temporary hose
(disconnect
after filling)
Non-return
valve
Automatic
air vent
Hosepipe
(disconnect
after filling)
Additional
stop valve
Double check valve
assembly
(note direction of flow)
Hose connector
Note.
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.
1. General
a. The installation must comply with the requirements of
BS.6798 and BS.5449.
b. The installation should be designed to work with flow
temperatures of up to 82oC.
c. All components of the system, including the heat
exchanger of the indirect cylinder, must be suitable for a
working pressure of 3 bar (45 lb/in
2
) and temperature of
110oC. Care should be taken in making all connections
so that the risk of leakage is minimised.
2. Safety Valve
A spring loaded safety valve complying with the relevant
requirements of BS.6759 must be fitted in the flow pipe, as
close to the boiler as possible and with no intervening valve
or restriction. The valve should have the following features:
a. A non-adjustable pre-set lift pressure not exceeding 3
bar (45 lb./in
2
)
b. A manual testing device.
c. Provision for connection of a discharge pipe.
The valve
or discharge pipe should be positioned so that the
discharge of water or steam cannot create a hazard to
the occupants of the premises or cause damage to
electrical components and wiring.
3. Pressure Gauge
A pressure gauge covering at least the range 0-4 bar (0-60
2
) must be fitted to the system. The gauge should be
lb./in
easily seen from the filling point and should preferably be
connected at the same point as the expansion vessel.
4. Expansion Vessel
a. A diaphragm type expansion vessel must be
connected at a point close to the inlet side of the pump,
the connecting pipe being not less than 15mm (
nominal) size and not incorporating valves of any sort.
b. The vessel capacity must be adequate to accept the
expansion of the system water when heated to 110
o
F)
(230
c. The charge pressure must not be less than the static
water head above the vessel The pressure attained in
the system when heated to 110
least 0.35 bar (5lb/in
2
) less than the lift pressure of the
o
C (230oF) should be at
safety valve.
For guidance on vessel sizing refer to the table in Frame
6. For further details refer to BS.5449. For IE refer to the
current edition of I.S. 813.
5. Cylinder
The cylinder must be either of the indirect coil type or a
direct cylinder fitted with an immersion calorifier which is
suitable for operating on a gauge pressure of 0.35 bar
2
(5lb./in
) in excess of the safety valve setting.
Single feed
indirect cylinders are not suitable for sealed systems.
6. Make-up Water
Provision must be made for replacing water loss from the
system, either:
a. From a manually fitted make-up vessel with a readily
visible water level. The vessel should be mounted at
least 150mm (6") above the highest point of the
system and be connected through a non-return valve to
the system, fitted at least 300mm (12") below the
make-up vessel on the return side of the domestic hot
water cylinder or radiators.
b. Where access to a make-up vessel would be difficult by
pre-pressurisation of the system. Refer to 'Filling.'
1/2"
o
C
Classic FF -
Installation & Servicing
9
GENERAL
6
SEALED SYSTEM REQUIREMENTS - continued
7. Mains Connection
There must be no direct connection to the mains water supply
or to the water storage tank supplying domestic water, even
through a non-return valve, without the approval of the local
water authority.
8. Filling
The system may be filled by one of the following methods:
a. Through a cistern, used for no other purposes, via a ball
valve permanently connected directly to a service pipe and
/ or a cold water distributing pipe.
The static head available from the cistern should be
adequate to provide the desired initial system design
pressure. The cold feed pipe from the cistern should include
a non-return valve and a stop valve with an automatic air
vent connected between them, the stop valve being located
between the system and the automatic air vent. The stop
valve may remain open during normal operation of the
system if automatic water make-up is required.
b. Through a self-contained unit comprising a cistern,
pressure booster pump (if required) and, if necessary, an
automatic pressure reducing valve and flow restrictor. The
cistern should be supplied through a temporary connection
from a service pipe or cold water distributing pipe.
This unit may remain permanently connected to the heating
system to provide limited automatic water make-up. Where
the temporary connection is supplied from a service pipe
or distributing pipe which also supplies other draw-off points
at a lower level then a double check valve shall be installed
upstream of the draw-off point.
c. Through a temporary hose connection from a draw-off tap
supplied from a service pipe under mains pressure. Where
the mains pressure is excessive a pressure-reducing valve
shall be used to facilitate filling.
The following fittings shall form a permanent part of the
system and shall be fitted in the order stated:
A stop valve complying with the requirements of
BS. 1010, Part 2 (the hose from the draw-off tap shall be
connected to this fitting).
A test cock.
A double check valve of an approved type.
• Thoroughly flush out the whole of the system with cold
water, without the pump in position.
• With the pump fitted, fill and vent the system until the
pressure gauge registers 1.5 bar (21.5lb/in
Examine for leaks.
• Check the operation of the safety valve by manually
raising the water pressure until the valve lifts. This should
occur within ± 0.3 bar (± 4.3lb/in2.) of the pre-set lift
pressure.
• Release water from the system until the initial system
design pressure is reached.
• Light the boiler and heat the system to the maximum
working temperature. Examine for leaks.
• Turn off the boiler and drain the system while still hot.
• Refill and vent the system.
2
).
Sizing procedure for expansion vessels: The volume of the expansion vessel (litres) fitted to a sealed system shall not be
less than that given by Table 6, multiplied by a factor of 0.8 (for flow temperatures of less than 88 oC).
Table 6
Safety valve setting3.0 bar2.5 bar2.0 bar
Vessel charge and initial0.51.01.50.51.01.50.51.0
system pressurebarbarbarbarbarbarbarbar
Total water content of systemExpansion vessel volume
The boiler is supplied fully assembled in Pack A, together with
a standard flue assembly for lengths up to 600mm (23 1/2"),
rear or side flue outlet, in Pack B.