Boulter Camray 5 combi – pressure rises to 2 bar, cuts out

[geoffains]

Hi All,

I have a Boulter Camray 5 oil fired combi boiler, and it is causing me real issues. After about 40 minutes of running the central heating it trips out. This happens when the pressure gauge reaches 2 bar (even though though the pressure gauge states a maximum running pressure of 3 bar. When the system trips the radiators are red hot, and there is no visible discharge from the expansion pipe outside

I have trawled internet forums until my eyes hurt, and most of the suggestions appears to relate to a faulty expansion vessel. When I pressed the car type valve there was no evidence of water, so I let enough pressure out of the water system for the heating pressure to go to 0, and with the system open pumped the expansion vessel up to 15 psi, then refilled the closed system, bled the radiators etc....

...and it still is tripping out at 2 bar

Any help / advice would be hugely appreciated.

Thanks
Geoff

 

[John506]

Could be over heating due to scaled up heat exchanger.

When was the system last flushed out and are inhibitors present?

 

[Tibbot]

The pressure gauge reading has nothing to do with your problem. It is temperature, not pressure which breaks the o/heat stat. Before looking deeper check the control stat phial is correctly placed in its pocket. Then check for trapped air by bleeding any air vents.

 

[geoffains]

John506 - Not sure on the history of the system, as only lived in the house for a year. Will flush the system and add necisary inhibitors asap though.

Tibbot - The problem being related to heat and not pressure makes complete sense. Come to think of it, whan I moved in, I was pretty sure that the boiler went off when it reached a certain temperture, and then came back on again. Now the burner appears to run constantly, untill the radiators are red hot, then it trips out.

Thanks both for your help. I will try what you suggest, and let you know how I get on.

Geoff

 

[oilhead]

Suspect the boiler thermostat. As suggested, make sure the phial is in the pocket. If it is, then replace the thermostat

 

[geoffains]

All sorted - thankyou all so much for your help.

Originally it was tripping out at 3 bar, after I re-charged the expansion vessel, it reduced to tripping out at 2 bar, which as you all quite rightly suggested was caused by the control stat.

The thermostat phial was not in its pocket, and to confuse thing further (for a novice) there was an old phail and control stat were still tied up in the web of wiring...so I traced them using the manual, place the correct one back in the pocket, and all works as it should. The boiler did work when I moved in, so it baffles me how it ever worked properly with the stat phial out of its pocket...

Thanks once again for your help - nice that kids are no longer waking up with cold hands...

Geoff