Baxi Solo 3 PFL and overheat

[markf]

Hi,

I had the above conventional boiler fitted in January and all was well - nice hot water and rads, quiet op, etc., but this morning I awoke to a cold house and no hot water.

Checking the boiler I noticed it was stone cold and the overheat lamp was lit, but the pump in the upstairs airing cupboard was circulating. I followed the instructions in the book and reset the overheat by switching the thermostat off for 10 secs and then back on. sure enough the boiler fired up and we eventually had hot water and heating.

Can anyone suggest what might have caused this (the boiler did not fire up this morning at all until I reset it) and if this is anything that is likely to happen regularly?

The boiler is located downstairs in a cupboard with more than the minimum clearances around it.

Cheers
Mark

 

[kevplumb]

does the pump keep running after the boiler turns off

according to the fault finding chart it should to dissapate exess heat

 

[markf]

Yes Kev, the pump does continue to run for a short while. In normal operation the boiler can burn for a minute and then shut down for 30 secs to a minute before firing up again, or sometimes it will burn continuously for 10 minutes.

But this morning there was no burn, or heat to show there had been burn, although the pump was still running and circulating cold water.

 

[nigeld]

Not sure but think this boiler shows overheat if electrical supply lost for short time-dont know if this helps.

 

[fireman22]

i had experience of this boiler and as your pump is controlled from the boiler and not when a motorised valve has opened, there must be a by-pass valve, maybe this is closed slightly too much or blocked. Basically when your heating shuts down pump carrys on pumping water away from the boiler if no bypass nowhere for water to go then overheat occurs

 

[markf]

Thanks for the pointers - all OK still since the reset so will just keep an eye on it.

As far as I am aware there was no power outage that night as all otherappliances showed the correct time. Perhaps there might have been a voltage spike or drop.