The whole unit (ie drain the system) or just the synchron motor within it?
Even if it's only temporary I'd prefer to not have to drain the system & mess things up at this time of the year as the wife won't be happy.
I have a 25 year old heating system that has functioned fine up until recently. Occasionally now I have a problem where the heating is on at the boiler but no heat is going to the radiators and the hot water from the taps gets really hot. This happens maybe once a week now.
There's a...