Heating coming on randomly

little_lass

HI everyone
Looking for some advice.
My energy bills have been really high for awhile now, I can't really understand why as I'm careful with the heating (timed to come on 1.5 hours in the morning and same in the eve), not loads of baths/ tumble drier etc.
I switch tariffs to get the best deal (currently with Tonik) and worked out that last month we used £150 just on gas.

Since then I've noticed the radiators are on/warm when the heating isn't on (all dark on control panel as it's outside heating times), and during the night (we never have heating or hot water on at night) I can hear the boiler igniting etc although I don't think the heating is coming on then.

Any ideas/advice gratefully received.
Thank you for reading my long post!

Talldave

Sounds like a problem for a skilled heating engineer.  The control of a boiler is really quite simple, but it's working out where the failure is that takes skill. Something is "calling for heat" when it shouldn't be. It's got to be the programmer, valves or the boiler itself that's at fault. Warm radiators when heating is off shouts valve problem but depending on the wiring configuration it might be something in addition to the valve that's firing up the boiler.
There could even be a frost protection stat set too high somewhere that's firing the boiler.

tim_p

Do a few meter readings before going to bed and ideally before the heating is set to come on in the mornings to get an idea of how much, if any, is being consumed. Other than the frost stat the problem could lie with a two port valve but that would usually mean you got hot rads when hot water was selected. Try some process of elimination by turning off the entire boiler, then just the heating or DHW etc alongside meter readings to try to pin it down. 

matelodave

Depending how your controls are configured and wired it is possible for a two or three port valve to be stuck and some of them do have an auxiliary switch which controls the boiler and pump.
Unless you can identify how your system is configured and you are capable of a some fault finding (including the controls) then you'll probably have to get a heating engineer in to check it all out

dogshome

Some boilers have a built-in  Hot water tank, the idea being that an opened tap delivers hot water almost immediately rather than waiting whilst for the boiler to heat it from cold - the boiler fires up randomly to keep the tank at a set temperature - Look at the manual, there should be an option to turn this feature off

This should not heat the radiators, unless there is a fault with the 3 port valve