boiler losing pressure no sign of water - expansion vessel insert fix

[@JohnMcCambley]

Great video and this is exactly what happened on our Combi. After 2 previous visits from a plumber, who was talking about potentially digging up flooring for leaks, it was actually this little valve that was the main problem. Your video was so timely and helpful.

[@petegasguy]

Brilliant… really glad it saved you some hassle. Sounds corny but stuff like this makes it all kinda worthwhile.

[@hamzaparvais3948]

Thank you for sharing

[@HughieMunro]

They put a dust cap on, with a rubber gasket at bottom so it’s not an issue. Until someone checking the pressure loses it

[@GaetanoCostanza]

Not always it could just be condensation. Need to test it to see if it's just condensation or faulty vessel

[@ekadjeka]

Good video thanx

[@elliotwilliams7421]

Great video mate. My boiler is loosing pressure over a few hours when switched off, seems to hold when the heating is on, no visible leaks internally or externally, all radiators are still full, no water coming out via the PRV by the looks of it, but.......the condensate trap has started filling up and going into fault mode. Could it be leaking into the condensate? I'm an electrician, COMPEX qualified, used to work on industrial boilers so I'm not clueless on this type of stuff

[@petegasguy]

Ewwww a sparky 😂😂😉 If your condense is filling when boiler is off then probably a pinhole in heat exchanger… which is a biggie. Unlikely to be a plate heat exchanger issue… Bit of a weird issue that… but if water going through condense pipe with no demand then i’d be suspecting a knackered main heat exchanger

[@elliotwilliams7421]

@@petegasguy 😄 can't believe I've had to lower myself and ask.......hahaha I let the system cool, turned it off, shut off the valves for the heating and it still drained from .5 bar in about 4 hours. It's an old boiler that was getting upgraded and moved later this year so it's not that bad. Piece of shit ariston microgenus, must be 20 years old

[@elliotwilliams7421]

@@petegasguy just before winter last year the condensate started filling up and leaking, put the heating on and the condensate no longer fills up, works as it should, turned the heating off recently and within a week the boiler had emptied and the trap was full again.

[@petegasguy]

@@elliotwilliams7421 meh - new boiler if it’s an ariston microgenus … stick £2500 aside and get yourself a decent baxi. What’s that, like a morning’s work for you lot??

[@elliotwilliams7421]

@@petegasguy £2500, that include installation? I've got a vokera up the attic somewhere. Was fitted on a job, not powerful enough so it was replaced, got it for £50 hahaha Honest guv, we don't earn that much, cost of materials, fuel........

[@MetalboxJ]

My vaillant boiler cuts out, the light flashing on the front indicates there's no water in the system, but it's at 1.5 bAr. ??

[@waynewalton8139]

I have this exact issue. I have tried swapping the valve core to no avail, I have tried cleaning inside the valve step where the o-ring on the core sits, still no luck. Definitely the valve that is leaking but can't seem to sort it. New vessel it is then.

[@petegasguy]

Sorry to hear that mate… sometimes a little bit of corrosion internally can mean its difficult to get a proper seal. Potentially a very thin strip of ptfe?? Good luck either way.

[@305deanna]

Hi Pete great info ...I had an engineer out for pressure lose( actually 5 of them) the last one fix it at a cost of 800£ two weeks later pressure loss again he comes back and said i now need a new boiler at 2000 ! I'm thinking could i try to change the valve as you suggested....as maybe an old timey plumber would repair the problem and most modern plumbers wouldn't ???...anyhow filling it everyday now and can't find where the waters going ...my rads are all ok ....Idea combo 35 = 12 yrs old .....any suggestions please ....would it be reasonable cost wise if the whole vessel needed replacing ??? thanks so much deAnna

[@petegasguy]

Google ‘combicert’ and give me a bell if you like. I have 5 mins spare to have a chat

[@petegasguy]

Best thing to do is to turn the boiler off and let the system cool. Fill up the boiler to a specific point (1-1.5bar…) and the leave it. Does the pressure drop after a few hours? If not then turn the boiler on and turn heating on. Watch the pressure gauge… what happens after a few minutes… does the pressure start to rise? New expansion vessel, fitted… probably around £150 - £170 ish - no a difficult job. If you watch the video again you’ll see an explanation… press the schrader valve and see if water comes out - if it does then it’s knackered. If it doesnt then chances are it just needs the valve replacing/reseating and then the EV recharing via a pump

[@in4dakill470]

Hi Pete, I have a Vaillant aqua Plus combi boiler which has a leaking expansion vessel. I've been told by the engineer that the boiler would need to be removed from the wall to replace the expansion vessel as its fitted to close to the ceiling and it can only be done from the top. Is this true or can it be replaced from the front by removing the front panel? Thanks for your help.

[@petegasguy]

It wouldnt shock me if that were the case. The aqua plus is quite a rare one and i can’t say i’ve ever taken one out... but - easiest way to check is to call vaillant and ask their tech guys. Like i say - it wouldnt shock me... some are designed like that.

[@TheStressD]

Hi mate great video, my ideal logic plus 30 keeps losing pressure. The valve won't come out, have they fixed it in there so it can't be removed by any chance? It just spins around making a clicking noise at the very last turn, have you experienced this before? I know how these companies are and they probably want you to replace the whole vessel.

[@petegasguy]

Sounds like it may be snapped internally or something. No - never seen one where you can’t just take the inner valve out. Sorry mate

[@TheStressD]

@@petegasguy OK thanks nice one

[@martindrury9740]

Hi. I've got a water leak behind my Vokera 20E boiler. Could the expansion vessel be leaking? If so how easy is it to change.

[@petegasguy]

What makes you think it’s expansion vessel? Without seeing it it’s very difficult to say. I dare say it’s not the first time a vokera has leaked from there. Get someone out and turn it off mate - don’t want the water doing any damage to electrics. Isolate under the boiler

[@martindrury9740]

@@petegasguy It's been loosing pressure and no signs of leaks any where else. I have switched off the electric to it and isolated the water. I just thought it could be because the water is running down the wall at the back

[@petegasguy]

@@martindrury9740 potentially mate - the ev is down the back on them. Only thing you can do is take a look and try to see where it’s coming from. I’ve seen vokera’s leak from pretty much everywhere 😂

[@martindrury9740]

@@petegasguy Cheers. I will look again tomorrow. I guess it's removed from the top?

[@petegasguy]

@@martindrury9740 library.plumbase.co.uk/flipbooks/RE/vokmyn20e_22550_t/mobile/index.html#p=24 Page 21

[@leestar7156]

Interesting.. just had my heat exchanger replaced because I isolated my boiler for 1 month and it still lost pressure. My expansion vessel needed recharging too the engineer said.. anyway 2 weeks later still losing pressure 😩

[@petegasguy]

Sorry to hear that mate. Ok - get a balloon/sandwich bag/anything you bloody well like - and tie it over the prv outlet that’s outside. Let’s rule that out first - before we start messing with stuff. Then - if dry let’s see if it’s coming out of condense. Does your pipework go under ground floor level (I.e. somewhere you wouldn’t notice if there’s a leak?). Are your isolators holding correctly....?

[@petegasguy]

How did the engineer diagnose a new heat exchanger...?? Was it actually new or one taken from one he had? Heat exchangers tend to be expensive bits of kit - I tend to direct people to manufacturers for a one time repair when they go as it’s cheaper for the customer in the vast majority of cases. Other option for leak - potentially it’s an issue with the plate heat exchanger... but I’m sure your engineer would have checked (less likely as the pressure from your cold mains side would have equalised out)

[@leestar7156]

Pete Combicert thanks for the reply. Before lockdown I was losing 1 bar pressure a week in January. The engineer wanted to isolate the boiler for few days to determine if it was the boiler or CH. I didn’t want to at the time because we had a new born and the wife is temperature OCD ( don’t ask ) I said I’d do it when the weather picks up. By this time I was gradually topping up pressure the less the CH was on. Lockdown happened and in August I closed the flow and return valve off for a month, during that time I lost 1 bar. Phoned boiler cover and engineer said it was heat exchanger. 2 weeks after heat exchanger was replaced still dropping pressure so I decided to phone IDEAL logic instead of my insurance. They sent their engineer out and said the only thing left to change on the boiler regarding pressure dropping was expansion vessel and PRV. When the engineer looked at the boiler straight away he was your expansion vessel is completely flat, zero air or water came out when he pressed the valve. Funny enough the 2 times the boiler insurance engineer came out to service and repair he said it was flat too, so in 12 months it’s gone flat 3 times. Anyway the IDEAL engineer has changed the expansion vessel and PRV, he said if the pressure drops it’s a leaking pipe under the downstairs floor. It’s been 1 day so far so I’m still waiting.

[@leestar7156]

Oh and about the isolators, the IDEAL engineer said when I isolated the boiler they may not have been fully closed and when I opened it up and lost a little bit more pressure I might have been losing it all along.

[@petegasguy]

Shit! Sounds like you’ve been hammered on this - hopefully insurance company won’t hammer you too much upon renewal. Seems made the heat exchanger was replaced when they knew expansion vessel as low... it’s (generally) the last thing you’d look to do. Keep us updated mate - hope it starts behaving

[@allfor1andoneforall]

Can you direct me to the valves on eBay please for ideal combi appreciated .

[@petegasguy]

www.ebay.co.uk/itm/20x-Tyre-Valve-Core-Insert-With-Remover-Tool-Schrader-Car-Bike-Motorcycle-Wheel-/184261714646?_trksid=p2349624.m46890.l49292