Supplied By www.heating spares.co Tel. 0161 620 6677
13
221474C
4 Heating System
Diagram 4.2
BOILER
3-LITRE
MAKE-UP
BOTTLE
(if required)
NON-RETURN
VALVE
AUTO AIR
VENT
DOMESTIC
WATER
HOT
COLD SUPPLY
FILLING
POINT
DRAIN
POINT
MIN. 22mm
DIA. BY-PASS
'B'
'A'
BY-PASS
VALVE
FLOW CONTROL
VALVE
HEATING
CIRCUIT
RETURN
ADDITIONAL
EXPANSION
VESSEL
(if required)
2818
METHOD 1
METHOD 2
METHOD 3
SUPPLY STOP
VALVE
SUPPLY
PIPE
HOSE
UNIONS
SERVICING
VALVE
TEMPORARY
HOSE
HEATING
SYSTEM
HEATING
SYSTEM
TEMPORARY
HOSE
HOSE
UNIONS
SERVICING
VALVE
SUPPLY
PIPE
SUPPLY STOP
VALVE
DOUBLE CHECK
VALVE ASSEMBLY
HEATING
SYSTEM
SERVICING
VALVE
SUPPLY
STOP VALVE
SUPPLY
PIPE
HOSE
UNIONS
DOUBLE CHECK
VALVE ASSEMBLY
OVERFLOW
CISTERN
COMBINED
CHECK VALVE
AND VACUUM
BREAKER
PRESSURE
REDUCING
VALVE
0051M
Diagram 4.3
4.9 Filling Sealed Systems
Provision for filling the system at a low level must be made.
Three methods of filling are shown in diagram 4.3. There must be
no permanent connection to the mains water supply, even through
a non-return valve.
NOTE: It is important that fittings used for
connection to potable water comply with the water undertakers
requirements.
4.10 Corrosion Inhibitor
If an inhibitor is to be used in the system, contact a manufacturer so
that they can recommend their most suitable product.
When fitting the boiler into an existing system, special care should
be taken to drain the entire system, including radiators, then
thoroughly cleaning out before fitting the boiler whether or not
adding an inhibitor.
4.11 Draining Tap
A draining tap must be provided at the lowest points of the system,
which will allow the entire system to be drained. An additional
draining tap MUST be fitted close to the boiler.
The flow and return isolation valves are provided with drain points
for boiler heat exchanger drainage.
5.1 General
The domestic hot water service must be in accordance with the
rules in force in the countries of destination.
5.2 Water Pressure
For the minimum and maximum working pressures of the domestic
hot water circuit of the boiler, refer to Section 1.6. If the cold water
supply pressure exceeds the maximum, a pressure reducing valve
must be fitted in the supply to the boiler to reduce the pressure to
within the limits given.
5.3 “Hard” Water Areas
In areas where the water is “hard”, that is, more than 200mg/litre,
it is recommended that a proprietary scale reducer is fitted in the
cold supply to the boiler. Check the total water “hardness” using the
kit supplied, in the door, following the instructions given. Consult
the local water company for additional advice.
A double check valve assembly must be fitted upstream of the scale
reducer. For the relative position of the scale reducer and pressure
reducing valve, if required, refer to the manufacturer’s instructions.
5 Domestic Hot Water System