Help request - Central Heating only comes on if water is also being heated

[MartinDowson]

Hi. I'm a complete novice with Central Heating, and so I'm somewhat mystified by my current problem. Any thoughts from the experts here would be much appreciated.

My problem is manifesting itself in the following manner:

If hot water is drawn off whilst the system is quiet during the day (or overnight), then when the heating is due to come on it initially works and the pump starts. Then once the house has warmed and the thermostat has cut the heating, then as the house cools it doesn't come on again.

If no hot water is drawn off whilst the system is quiet, then when the heating is due to come on in the evening nothing happens.

I requested a plumber, who mumbled something to me about "low voltage to the 3-way valve" (?) and then did not turn up as he had agreed. So before trying someone else, does anyone on this forum have any ideas?

Many thanks in advance for the replies.

 

[Darren Jackson]

It does sound like a motorised valve is faulty, but you need a local gsr engineer to come out and fault find the problem, try posting on the need a plumber thread on this forum, and hopefully a reliable qualified plumber in your area will help you out. Good luck.