I have switched off the central heating at the controller (set it to OFF) and drained the central heating system down.
NB : My water heating as always is set to continuous.
After some time, I heard the Grundfos central heating pump come on and make a whirring sound (presumably as it is running dry).
I immediately switched off the hot water at the controller too and the pump stopped too.
I'm pretty confused here as I thought the central heating pump could only come on when the central heating was switched on at the controller and would have no reason to come on for hot water heating at all?
Ideas anyone?
NB : My water heating as always is set to continuous.
After some time, I heard the Grundfos central heating pump come on and make a whirring sound (presumably as it is running dry).
I immediately switched off the hot water at the controller too and the pump stopped too.
I'm pretty confused here as I thought the central heating pump could only come on when the central heating was switched on at the controller and would have no reason to come on for hot water heating at all?
Ideas anyone?