Boiler overheating everyday.

[Projectfocus]

I seem to have an issue with my boiler overheating. I can't remember the model number but I can find that out tonight. I think I have found what is causing it but I am not sure how to stop it.

Firstly here is some background. This issue has been happening for over a year and what we did to get around it was to manually put the heating on and off and not have this controlled by a thermostat. Mainly because when we moved in the heating system was all wrong and did not work.
So when we redid the kitchen and changed the programmer we decided to change the thermostat also to get it all working properly on temperature controlled central heating. This then started the problem happening again but it was the spring so did not worry us to much. Now it is doing it every day.
What I think is happening is the thermostat is advising the controller that it is at temperature. This then shuts off the pump and the boiler. This however does not always happen and the boiler keeps running. This I gather then boils the water in the pipes and or drags air through as the pump is not running. This then overheats and the pipe crash and clatter for a few minutes. When the temperature goes below the call for heat value it then starts the pumps again. The boiler is still on overheat so nothing happens. It is almost as if the relay that is driven from the programmer is sticking. Or it is not getting the proper control signal.
What do you think this could be?
Is it worth getting a specialist in?
Is this something that would be easily rectified based on the description of the fault?

If you need any more info I will try and get all you require. Thanks in advance for your help.

 

[Projectfocus]

It was only through reading some other posts on this site that I have remembered the company that make the boiler. It is a Baxi boiler but I am not sure how old. A few things I do know is that it does do the Hot water as well. Although I never have that side of it turned on due to not really using Hot water in our house. It seems that there seems to be enough seeping through that our airing cupboard still seems to get quite warm even without the Hot Water on. Another thing I thought I should mention as from reading other posts this may be relevant. All of the Rads were replaced about 2 years ago and all fitted with Thermostatic Valves. Well all apart from 2, The bathroom and the spare room.

I hope this information helps.

 

[bellairaphon]

u need to be more specific on what boiler it is. however it seems like a temperature sensor problem

 

[Projectfocus]

The boiler is a BAXI SOLO 2 40 PF.

This means nothing to me but for some strange reason I turned down the Thermostatic valve that is located under the thermostat and it did not go off on Overheat last night. So I really am not sure what the problem is now. Unless it was just a coincidence.