Baxi 80 combi boiler

[rmbp]

Hello there, I've got a baxi 80 combi thats losing pressure, all pipework is exposed and there no leaks. The rad's are ok, If I set pressure to 2bar It drops down to 0.5 bar in about tens minutes. The heating works fine until the pressure drops and the hot water operates no problem. But can't figure out why the pressure is dropping, Any suggestions are welcome.
This problem seems to occur quicker when the heating is turned off.

 

[mcmoby69]

have you checked the pressure relif valve outside ? is it dripping/ running?could besome muck in the valve stopping it from shutting off properly.

 

[Mike Jackson]

The other possibility is the main heat exchanger is leaking into the sump and draining away through the condensate drain.

Does this just happen when it is working or all the time?

If it is all the time you can narrow down the cause by re-pressurising the system and shutting the boiler isolating valves. If the pressure drops at the boiler the fault is within the boiler. If it stays steady and then drops when the valves are re-opened it is in the pipework. Obviously don't run the boiler while you are checking this.

Mike

 

[rmbp]

Hello there, I've got a baxi 80 combi thats losing pressure, all pipework is exposed and there no leaks. The rad's are ok, If I set pressure to 2bar It drops down to 0.5 bar in about tens minutes. The heating works fine until the pressure drops and the hot water operates no problem. But can't figure out why the pressure is dropping, Any suggestions are welcome.
This problem seems to occur quicker when the heating is turned off.

Just replaced the prv everything spot on, Thanks for advice.