
Fig. 17. Typical Open Vent Fully Pumped System (Honeywell ‘Y’ plan).
Automatic
air vent
Fig. 18. Typical fully pumped sealed system (Honeywell ‘Y’ plan).
Expansion
Vessel
Diverting
valve
Pump
Radiator
N.B.
A drain cock should be
installed at the lowest point of
the heating circuit
Domestic hot
water
cylinder
Pressure
gauge
Safety valve
To system filling device (see Fig.14)
Boiler
Automatic bypass valve to be fitted
where thermostatic radiator valves
are fitted on all radiators
12