Boiler lost pressure whilst on holiday

ILoveSittingDown

I have been on holiday for a week and when I left to come home, I turned the heating on via Hive so it would be toasty when we got back. On returning home several hours later, the house was still cold and upon inspecting the boiler, it had errored out and the pressure gauge was sat on zero. I re-pressurised the boiler and reset it, and the heating has been running since for 3-4 days with no issues. I went around the house checking for any leaks from the central heating but couldn't see any.

Should I be concerned about the pressure dropping to zero? It hasn't dropped since I re-pressurised it and I can't see any evidence of leaks, although I haven't lifted the floor boards to check 100%.

Bendy_House

A complete drop to 'zero' is a cause for concern, although what made this happen could be relatively minor or relatively serious - so don't panic yet...

Just keep it monitored. Almost certainly it'll happen again - either slowly or quickly - and then you can start to discount causes.

What, I guess, is the worst-case scenario - a hidden leak from a hidden pipe - is the least likely.

Soot2006

As above, it can be anything. Mine did it, but very slowly, until suddenly one day we were cold as it had emergency shut down.  And then again, over the next three months. Couldn't find an obvious cause and boiler is 1 year old so got the guy who installed it in to have a look and he found the tiniest pinprick leak in the bathroom. It wasn't obvious as as area that gets splashed anyway and so so tiny. Tightened that up and now pressure is fine again.  It can drive you mad these things ...

ILoveSittingDown

Thanks both. I'll monitor it and if I see it happening again then I'll call a plumber out.

NSG666

Just to add to what Bendy has said, make sure you check it when the system is cold as the pressure should increase when the heating is on. Also check that all the radiators are getting hot at the top as some of them might need bleeding if the pressure dropped so low then top the boiler pressure back up to 1bar (when cold)

ILoveSittingDown

NSG666 said:

Just to add to what Bendy has said, make sure you check it when the system is cold as the pressure should increase when the heating is on. Also check that all the radiators are getting hot at the top as some of them might need bleeding if the pressure dropped so low then top the boiler pressure back up to 1bar (when cold)

Thank you!