Hi,

We have just moved in a house which has been vacant for about two years. There is an Ideal Classic FF350 boiler within an open vent system controlled by a British gas UP1 programmer. We've tried to program/use the Hot Water Advance function but the boiler also triggers the CH despite the CH controls being off. We've had to use the immersion switch on and off, which is far from being economical and impractical... Sorry it might be nothing but we've always had combis and this systems is new to me...
Is this normal after long period of inactivity or could there be a fault?

Many thanks.

Millythecat, September 2013

Many thanks to both of you!

Millythecat, September 2013

you will have 2 zone valves, 1 each for heating and the hot water, the heating one will be slightly open, meaning when you have the hot water on, it is also going down the heating pipes. as a temporary measure turn down the thermostats on the radiators, but you will need a heating engineer to replace the valve

sinky7062, September 2013

most likely a faulty diverter valve

kash, September 2013