Skip to main content

Ready to hire?

Post your job in minutes, browse real reviews and choose who to speak to.Post a job

Need some tips or advice?

Ask a question
Central Heating

Boiler losing pressure mystery, HELP!

Anonymous user 23/02/2024 - 3.42 PM

My boiler is losing 1.5 bars of pressure from 20:00 to 07:00. We’ve got British Gas home care and so far we’ve had the boiler isolated and it retained pressure. When the boiler was unisolated the pressure dropped down to 0 pretty much instantly, indicating it was an issue with the central heating. ADI leak detection was called out because British Gas’s third party was going to be weeks. They used acoustic, damp meters and gas tracing but found no leak. The gas tracing was at 4 bars or pressure for 90 minutes and no drop off pressure. British Gas came back out to check the boiler once again and stating nothing was wrong with the boiler but noticed a weeping radiator valve which was replaced. This is no longer weeping. The boiler continues to lose pressure and a F4 leak sealant has been used now. However, the pressure still drops, there’s no air in radiators each time I pressurise the boiler. So my question is this caused by a leak or is it the boiler?

Are you a tradesperson and able to answer this question?

4 Answers

Anonymous user

Your expansion vessel is split or needs to be aired. This is causing the pressure relief valve prv to activate. Causing ur central heating water pressure to be emptied through ur overflow pipe
Answered9 August 2021
4

CTSGROUP

Rating: 4.9 out of 5
Coventry
It is clear that you do not have a leak on your system. Either your Main Heat Exchange is breached and the water going out the condense line or the expansion vessel has failed and its going out the prv so 1/2 bar pressure could be equivalent to two small drops of water
Answered9 August 2021
0

Anonymous user

It will be the expansion vessel, will be split or the diagphragm split, or could need recharging
Answered15 August 2021
0

Anonymous user

Well if the boiler is isolated for 24 hours cold generally speaking would individuate the the heating system it’s self. If you have a copper cylinder isolate the flow and return to that as it could well be a faulty coil BELIVE ME IVE BEEN THRE. Cut a section of pipework in to be able to air test the coil you’ll know in 30mins to one hour
Answered18 August 2021
0