10
Filling the Domestic Hot Water & Heating System
The Domestic Hot Water can be filled by opening one of the hot water taps in the house to allow the air in
the boiler to escape and then the mains valve opened to allow water into the boiler. The 3Bar boiler
pressure will be controlled by the pressure reduction valve. The central heating system should be filled by
connecting the filling loop to the water mains and the valves turned on. The heating system will fill and
when the system is bled at the radiators, the proper pressure should be set at 1.5Bar... After the initial
filling the boiler and the radiator system should be flushed and drained, The domestic hot water side can
be flushed by opening the drain valve at the bottom of the tank and letting the water flow until flushing is
complete. The central heating system can be flushed by connecting the filling loop and allowing water to
flow through the system until flushing is complete. Any leaks apparent should be attended to. A suitable
inhibitor should be added with the filling loop disconnected, by filling the required amount of inhibitor
through the 15mm pipe stub provided for the auto air vent on the flow side of the central heating system on
top of the boiler. The heating system can then be filled to its proper pressure of 1.5Bar, the pump should
be run for some time to expel all the air from the system including bleeding the radiators. Finally the
radiators should be balanced and the pump set to the lowest speed that will suffice in supplying full heat to
all the radiators. It will probably be necessary to return to the house and bleed and refill the system to its
proper pressure after the system has been running due to the automatic bleeder reducing the pressure as it
removes air from the system during the settling in period.
. The filling loop should always be disconnected and both valves closed after filling is complete. It is also
important to check the output temperature from the Domestic Hot Water valve. Output temperature is
normally factory set at 55Deg C but can be adjusted to the house holders requirement by removing the
locked blue plastic cap by the centre Allen screw and resetting the valve. The system pressure should be
checked after a settling period of approx one month.
