Gas Boiler Problem?

[dunnitall]

Would like some advice please if at all possible. The boiler is BAXI SOLO 2 if that means anything to those in the know. Had chap come out to it because it wasn't switching on properly, sometimes would work, sometimes not then it stopped coming on.

Chap said it was circuit board which had burnt out...he showed us and replaced with new one there and then. Wow...boiler so much better. However, putting the thermostat on 17 degrees the boiler just seems to keep going, just "fading to off" for 30 seconds or so, then switching on again. Because it seemed to be getting too hot at 17 degrees, we turned it down to 15 degrees and it hasn't come back on even though the room and rad is cold. Put thermostat back to 17 and all comes on again.

I know nothing at all about these things so wonder if someone with the knowledge may be able to tell me if this is as it should be or still something not quite right. With the heat the rads throw out at 17 degrees, we shouldn't need it any higher even in freezing temps!! Lol

TIA for your comments.

[The Builder]

Assuming it's the right circuit board, and not one for a Solo 1, then it does sound as though there was more at fault than just the board.

First thing would be to replace one or more of the heat sensors in the boiler. They're basically just thermostatic controls. Any one of them could throw up all kinds of problems such as this.

I really do feel for boiler techs in these cases. It's so often down to trial and error until you find the offender.

[dunnitall]

Thanks Builder, I did wonder if it was going to be 'one of those problems...trial and error' nothing much is simple nowadays lol...tighten a screw/turn this...etc. I will get it sorted I hope and get the chap back, many thanks again.