Thanks for the reply. What is the power head and how is it removed? Is it the electrical piece on top of the three-way connection if so do I have to drain the system?
As for inhibitor, it was added when it was first installed.
Regards
Bluepeteten
I have a gas fired CH system about 9 years old, Ideal Classic Boiler LXRS & RS sealed gas boiler, Grundfos pump, Honeywell V4073 3 way port valve.
I have noticed that although the thermostat (Drayton) operates correctly the rads remain hot regardless of the setting. If I switch the CH off the...