8
221873B
1.7 Gas Supply
The gas installation shall be in accordance with the rules in force
in the countries of destination.
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. With all other appliances operating.
1.8 Electrical Supply
WARNING. This boiler must be earthed.
All system components shall be of an approved type.
The electrical installation shall be in accordance with the current
rules in force in the countries of destination at the time of
installation.
Connection of the whole electrical system of the boiler and any
heating system controls to the electrical supply, must be through
one common isolator.
Isolation should be by a double pole switched fused spur box,
having a minimum contact separation of 3mm in each pole.
The fused spur box should be readily accessible and preferably
adjacent to the appliance. It should be identified as to its use.
Alternatively, a fused 3A 3pin plug and unswitched socket may
be used, provided they are not used in a room containing a bath
or shower.
The mains supply cable and other cables connected to the
boiler must be the PVC flexible type of at least 0.75mm
2
(24/
0.20mm) .
1 General Data
Diagram 1.2
1.9 Heating System Controls
The heating system should have installed: a timer and room
thermostat controlling the boiler.
Thermostatic radiator valves may be installed, however they
must not be fitted in a room where the room thermostat is
located.
Note: All systems must have at least one radiator not fitted with
a thermostatic valve.
Note: For further information, see The Building Regulations
1991 - Conservation of fuel and power, 1995 edition - Appendix
G, table 4b.
7664
Diagram 1.3
7641
FANNED FLUE
AUTOMATIC
AIR VENT
EXPANSION
VESSEL
MAIN BURNER
HEAT EXCHANGER
PLATE TO PLATE
HEAT EXCHANGER
PUMP
HOUSING
LOW WATER
PRESSURE
SWITCH
PRESSURE
DIFFERENTIAL
MICRO SWITCH
GAS VALVE
SAFETY
VALVE
DISCHARGE
OVERHEAT
CUT-OFF
TEMP.
SENSOR
TEMP.
SENSOR
MOTORISED
3 WAY VALVE
HOUSING
VALVE
BYPASS
VALVE
D.H.W.
COLD
INLET
D.H.W.
HOT
OUTLET
C.H.
FLOW
C.H.
RETURN
D.H.W.
MICRO SWITCH
GAS
SAFETY
VALVE
The appliance flue type is a C
12
and C
32
. This refers to a concentric
flue where the fan is downstream of the heat exchanger. The C
12
is
a horizontal flue termination, and the C
32
is a vertical flue termination.
