DIY Doctor UK DIY Forums

Hi, I have a combination boiler, sometimes it will turn its self on for a short time for no apparent reason, (its not a pre heating boiler BTW), no taps running, CH not on. It normally happens at night. Any ideas why it would do this?

Firstlt check you're not missing something simple like programmer set to timed mode ?

Could be a faulty sensor bringing the boiler on as the majority now have a frost stat. If the temperature drops the boiler will bring the heating on to prevent the pipes etc from freezing.

htg

Hi thanks for the reply, the timer seems to be set correctly, I don't think it has been cold enough recently for the frost sensor to have come on, what type of sensor could be causing it?

I have a friend who is a gas engineer, but he doesn't have a clue what would cause it, maybe you could point him in the right direction?


Thanks.

Make and model of boiler ?

Sorry didn't explain properly. I'm not saying it has been cold enough - i'm saying the sensor/frost stat may be faulty.


htg

you need a boiler engineer. there is clearly a fault with a sensor somewhere. could be one of a number of things that have already been stated, but without actually looking at it, it's impossible to say.

Hi sorry for not replying I've been busy lately, my british gas friend checked the frost sensor and said he thinks thats the problem, he has swapped it for a new one now so I will have to wait and see if the problem goes away.

Thanks for all your help.