Pressure dropping

Sheedy234

Hi folks

Big problem with my oil boiler system. Pressure is dropping from almost 1.5 bar to zero is less than an hr. My plumber is stumped he has tried everything and I had a leak detector out and he has found nothing. Just yesterday the plumber disconnected the flow vales to copper cylinder as a last chance . Leak guy coming back again tommorow. The heat is working fine as long as the pressure eis up,it is an old Firebird boiler. Any help welcome please I'm well sick of it 😪

Wearb

Any white smoke when it's running?

Sheedy234

No it looks and sounds fine

Wearb

It needs to be pressure tested then. Got the be going somewhere. Maybe put some cheap scent into the system water before pressurising.

Lenar3556

He should be able to nail it down better than that by pressure testing. Is heat a factor? Does it happen even if the boiler is off?

Has he tested/replaced the expansion vessel?

Have you put a container under the boiler blow off to confirm there is no water escape from here?

Wearb

Is it a condensing boiler. I know you said old, but they've been around for some time now.

Sheedy234

Hi,

I'm not up on plumbing ,I don't know if it is a condensing boiler ,it is a popular 82 Firebird. I don't know if expansion vessel has been checked. I have just put the pressure up and will check if it drops with no heat on and put an container underneath.

I will ask all these questions tommorow.

Thank you all so much I will reply back if problem found

Wearb

OK. Not a condenser.

If you're plumber hasn't already checked the vessel then he isn't up to much.

Since you posted that you had a plumber out, I've made loads of assumptions that he's done the basics at least.

Sheedy234

I would trust my plumber whole heartedly he is very honest well regarded so I would say yes he has. He is adamant there is a bad leak somewhere. Thank for you ideas and I will ask to make sure he has .

Sheedy234

Just went out and checked and the pressure has dropped with no heat on .

Wearb

What's feeding the boiler when you pressurise it?

I'm just wondering if there's a possibility of the pressure leaking back past the fill point.

Sheedy234

That the setup

Wearb

What's the disconnected pipe?

The flexible pipe looks to be the top up pipe?

Do you have your own well?

Sheedy234

It's where he disconnected the return flow to copper cylinder yesterday to see if that was the problem. He is coming back to reconnect . He was just trying to rule out . No to own well.

Wearb

https://www.boards.ie/discussion/comment/121344679#Comment_121344679

Expanding water has to go somewhere if expansion vessel cannot absorb it.

Sheedy234

This is a cottage over 150 yrs old and 20 yrs ago previous owner did work and I can safely say it was not professional. The boiler was probably second hand and installed by a handy man no doubt.

Wearb

https://www.boards.ie/discussion/comment/121344700#Comment_121344700

So you are on a mains supply?

Sheedy234

Yes mains supply

dmac.

Whilst I didn't have a leak so bad that it resulted in the pressure dropping in an hour, it did drop over about 12hrs.

The plumber that was called out advised that it was a pipe buried in the screed and to avoid digging up tiled floors to use a leak sealant additive as a first attempt to fix.

2.5 years on and it has worked fine with no pressure drop.

Hope this helps.

Sheedy234

Leak pinpointed I hope,half way across sitting room floor. Don't know how the leak guy didn't pick it up the last time as I heard it on the machine myself and it was really loud. Floor coming up next week so fingers crossed it will be sorted.

Thanks for all the input

thespecialon

sorry to hijack but similar query..my pressure is dropping but much slower, if oil boiler if off it doesn't seem to drop much if at all..The more boiler is on heating the more it seems to drop like 1.5 bar over few nights..Plumber had a look but doesn't seem to have any ideas, rand leak detector guy who said leak was too small for him to find! no visible signs of leak yet!..anyone every have similar

Wearb

Seeing as you've had a plumber out we have to presume he's checked expansion vessel and pressure relief valve?

thespecialon

I wasn't there when he called but he said he checked a few things and didn't see any issues( hes not the best communicator and I've been thinkin about getting a new plumber anyway)..He suggested calling the leak detector guy ..The pressure release valve isn't actually plumbed anywhere(outside etc) its just an open pipe in the hot water tank room so would see if water was coming from in