50
7.5 Draining The Central Heating System
If the need arises to drain the system, this can be
done as follows:
●
Switch the system to “WINTER” mode and ignite
the boiler.
●
Switch off the power supply to the boiler.
●
Wait for the boiler to cool down.
●
Connect a hosepipe to the system drain point and
locate the other end of the hose in a suitable drain-
age system.
●
Open the system drain valve (see
fi
g. 20).
●
Open the air vents on the radiators, starting with
the highest and moving down the system to the
lowest.
●
When the system has been drained, close the radiator breather valves and the drain valve.
●
If only the boiler needs to be drained, close the
fl
ow/return isolating valves on the heating circuit and
open the drain valve located at the bottom of the boiler on the pump manifold (see
fi
g. 20);
■
Draining the domestic hot water system
If there is a danger of freezing, the domestic hot water system should be drained. This can be done as fol-
lows:
●
Close the mains water supply valve.
●
Open all the hot and cold water taps.
●
On completion, close all the previously opened taps.
Fig. 1
Fig. 20