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Central heating when hot water system comes on so do the radiators
I have Glow Worm 80ff, Danfoss programmer CP715, Danfoss H series switching valve.
The radiator system works OK, but I notice that after a bath when the hot water system comes on the Danfoss valve goes to the middle position quite often (not always but usually) so that the radiators also come on and stays in that position even if I switch the radiators off at the CP715.
Is it the CP715 programmer faulty?

The first thing I would do is power down the heating altogether preferably when the valve is in the centre position.

Once the power is off, the valve should return to the heating off position with the cylinder coil side open. If it doesn't return then the valve is sticking. If it does return then operate it manually to ensure a smooth operation.

If that all checks out, then the possibility of a faulty timeswitch becomes more likely although there could be other possibilities such as a frost stat not working correctly.

I have a Baxi 80 combi ECO,it works OK on the HW side but when I switch on CH the boiler just stops and start every few seconds,new PCB+gas valve(not checked)micro switch,new Venturi,new Temp.switch,but it still wont work.any ideas.