Baxi Solo 2 overheat - I have checked other posts, but....

[Richduc750]

Hi there

I was hoping someone might be able to shed some light on the following problem, before I call out an engineer. I have checked for an answer on this board before posting.

Baxi Solo 2 80PF

5 bed house

The boiler has been running ok but there has been an intermittent very loud banging coming from the pipework around the HWC (usually at night when its colder, heating on). I have given the boiler a once over and noticed the overheat stat was not screwed into the boiler. I have swapped it for the new style overheat stat located on the flow pipe now.

However, now the overheat stat seems to be kicking in after a while (a few hours) on heating - the boiler shuts down and the overheat light comes on. It then needs resetting. In the mean time all seems ok, although the boiler does shut down and restart very often, but this is just it bouncing off the room stat temperature, I presume.

When both HW and heating is called for the situation is the same.

There is a slight hissing sound coming from the boiler, too.

To make matters interesting, when hot water only is called for the boiler fires up but shuts down very quickly, as if the hot water is already up to temperature. It then fires up again after a while just to do the same thing. I have checked the HWC stat which seems to be working ok and is set to 60 degrees. The only difference I can notice to the heating issue is there may be a louder hissing sound from the boiler before shut down, but that might be in my imagination.

I have checked as much as I can and the 2 port valve for the hot water seems to operate as does the pump which I have also bled. I have not checked the other valves as it seems quite complicated in there!

Pics here, hopefully, if you have time to take a quick look:

//www.diynot.com/diy/media/albums/solo-2-overheat.25695/

Any info gladly appreciated, as the missus is now demanding I call an engineer but I would at least like to be able to narrow it down or do some further investigation. I have not checked any tanks in the roof void yet for issues as I am not sure what to look for.

Thank you for taking the time to look!

Rich

 

[stardanny]

You need to check the pump is running.

Is all the radiators hot?

Pipework possible clogging up.

Possible boiler nearer end of life, quite old.

You need to get an engineer to have a look and advise you.

Daniel.

 

[AGAS]

why would you think an overheat stat tripping is a minor fault ??,you'll be lucky if just a faulty OH stat , you need to find out why the oh stat is tripping which sounds like its been going on for a while . it can be couple reasons why its faulting for which i recommend you get a heating engineer to have a look .

 

[dilalio]

It sounds like heat is not getting away from the boiler and being dissipated throughout the system, as it should. This is indicative of poor/no circulation and can be caused by a number of things... Defective pump, valves or blockages due to sludge. If your are not familiar with how your system functions then it would be better to call out an engineer. He'll likely check pump first then proceed through a fault finding check list which can be found elsewhere on t'internet!

 

[Richduc750]

ok thanks for the responses - I will get an engineer out - I just wanted to make sure there weren't any things I could do first just to check. BTW the reds heat up fine and the pump seems to operate as it should. Thanks again!