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7
Controls:
As a minimum it is recommended that a 2 chan-
nel timer and room thermostat is installed to control the
appliance. Thermostatic radiator valves may be fitted to the
system but must not be fitted in the room where the room
thermostat is fitted. There must be at least one radiator
installed with lock shield valves that should not be closed.
Further guidance can be obtained from the Domestic
Heating and Hot Water Guide to the building regulations and
GPG 302
NOTE: a differential pressure bypass valve MUST be
installed to maintain a minimum flow rate of 18 L/min
(20
o
differential at maximum heat input).
2.7 Domestic Hot Water System Requirements:
Domestic hot water circuits and their components must be
in accordance with the relevant standards and water sup-
ply regulations. Further guidance and recommendations
can be found in the building regulations G17 to 24 and
R17 to 24.
Additional
Expansion Vessel
(if required)
BOILER
Drain
Point
Bypass
(if required)
Flow Control
Valve
Heating
Circuit
Fig.2-2
Heating System
Method 1
Method 2
Method 3
Supply
Hose
Unions
Hose Unions
Service
Valve
Service Valve
Heating System
Heating
System
Heating
System
Service Valve
Service
Valve
Double Check
Valve System
Double Check
Valve System
Stop
Valve
Stop
Valve
Hose
Unions
Supply
Temp
Hose
Temp
Hose
Combined Check
Valve & Vacuum
Breaker
Supply
Stop
Valve
Overflow
Pressure
Reducing
Valve
Fig. 2.3
Filling Methods
