7
400
Central Heating
Detailed recommendations are given in BS 6798:1987 and BS 5449-1:1990, the fol-
lowing notes are given for general guidance.
Pipe Work:
Copper tubing to BS EN 1057:1996 is recommended for water pipes. Jointing should
be either with capillary soldered or compression fittings.
Where possible pipes should have a gradient to ensure air is carried naturally to
air release points and water flows naturally to drain taps.
The appliance has a built-in automatic air release valve, however it should be
ensured as far as possible that the appliance heat exchanger is not a natura col-
lecting point for air.
Except where providing useful heat, pipes should be insulated to prevent heat
loss and avoid freezing.
Particular attention should be paid to pipes passing through ventilated spaces in
roofs and under floors.
By-pass:
The appliance includes an automatic by-pass valve, which protects the main
heat exchanger in case of reduced or interrupted water circulation through the
heating system, due to the closing of thermostatic valves or cock-type valves
within the system.
System Design:
This boiler is suitable only for sealed systems.
Drain Cocks:
These must be located in accessible positions to permit the draining of the
whole system. The taps must be at least 15mm nominal size an manufactured in
accordance with BS 2870:1980.
Safety Valve Discharge:
The discharge should terminate facing downwards on the exterior of the building
in a position where discharging (possibly boiling water & steam) will not create
danger or nuisance, but in an easily visible position, and not cause damage to
electrical components and wiring.
The discharge must not be over an entrance or a window or any other type of
public access.
2.7
Gas Connection
The local gas region contractor connects the gas meter to the service pipe.
If the gas supply for the boiler serves other appliances ensure that an adequate sup-
ply is available both to the boiler and the other appliances when they are in use at
the same time.
Pipe work must be of an adequate size. Pipes of a smaller size than the boiler inlet
connection should not be used.
2.8
Water Connections
A
C
B
D
E
H
I
F
View of the Boiler Connections
Fig. 2.4
unswitched shuttered socket outlet both complying with BS 1363.
The point of connection to the Electricity supply must be readily accessible and adja-
cent to the appliance unless the appliance is installed in a bathroom when this must
be sited outside the bathroom.
Legend:
A = Central Heating Return (3/4”)
B = Central Heating Flow (3/4”)
C = Gas Inlet (3/4”)
D = Domestic Hot Water Outlet (1/2”)
E = Secondary return (1/2”)
F = Domestic Cold Water Inlet (1/2”)
H = Central Heating Discharge
I
= Domestic Hot Water Discharge
SC002A
