Ideal Classic FF 240 (Optia 40?) - Continues running

[JonathanAbbess]

I have an Ideal Classic FF 240 (same as Optia FF 40 I believe). Most of the time it seems to run correctly but occasionally when the time switch goes off the boiler continues to run. I can hear a motor running (not sure if it is a fan or the water circulation) and the boiler lights for a short period every few minutes. This continues even with the timer control unit removed (it's a potterton one where the electronics bit detaches from the base).

Switching the mains supply off obviously "kills" it, and when turned on again a number of hours later (next morning/evening) it seems "normal" again.

Obviously something needs replacing. Any idea what and where I can get one?

 

[HarrogateGas]

Sounds like you might have an S-Plan and one of the zone valve end switches is sticking.

 

[JonathanAbbess]

Many thank's HarrogateGas. I have looked up the "S-PLAN" circuit and can see exactly why you suggested that. Next time it fails I will know what to look for.