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No boiler pressure but no visible leaks - please help!
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As SparkieDave has said, its likely to be your Expansion Vessel.
If you are bleeding radiators, and repressurising to 1-1.5 bar and then firing the boiler, and the pressure rises/drops immediately, this usually indicates the expansion vessel is not doing its job (compensating for an increase in volume of the heated water).
Your best bet is to either contact a reputable company whom offer a 'contract type care cover' where they will not necessarily charge by the hour should you require them to trace&repair.
OR
If its visible, without removing any case/covers from the boiler itself (as this does contravene Gas Installation & Use Regulation 1998) you could re-pressurise your expansion vessel yourself!
The expansion vessel is usually red in colour (or silver, if German by design&manufacture) and will have a schraeder valve (a valve, similar to that of a bicycle wheel). If you merely remove the cap, place a foot pump WITH A PRESSURE GUAGE onto it and pump it to 1bar, then re-fill your system, you should find you've cracked it.
Only attempt this if you can see the expansion vessel without removing parts of the boiler, as you MAY interrupt the combustion seals and place yourself and others in danger.
If you can't see it, either join a contractual cover or request an engineer with a feasable hourly rate to carry out this activity for you. If you disturb the combustion seals, you are required, by law to check their integrity, along with the effectiveness of the Flue, Combustion Air, Gas working pressure(s) and Safe operation of the appliance (Hence, the need for a registered gas engineer)Mortgage Free Wannabe
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BlueMoonMole - I have spoken to husband and he says that is what my plumber friend is going to try next so I am hoping that will fix the problem. Having someone else outline it for me has reassured me so thank you for taking the time to reply to my query.0
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well today my plumber did something with a pump to add air and still the pressure dropped within an hour or two. Water is still coming out of the pipe that leads from the back of the boiler outside, it drips constantly and then a little flow of water comes out quickly and then drips some more etc. Plumber suggested finding the drain !!!! and draining down the system, cleaning it out and then using the fernox f4 to seal any possible leaks and then using a protector. He will also try to add more air into the sytem with a compresser (?) I think he said. I've bought the fernox sealer and just waiting for delivery of the cleaner but I am worried about all the water that keeps coming out of the back pipe outside - this seems a constant thing but the plumber says it's not a problem with the boiler - boiler is fine - but since he has already pumped air into the system and this hasn't sorted out the problem I am getting really worried. Moving into the house in 4 days time now. Just fed up of seeing the pressure dropping all the time no matter what we seem to try and we want a water meter fitting but daren't with all this water loss! LOL wondered why there were exclamation points after the word drain and came back to edit - doh! drain c-o-c-k!!!0
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Plumber sounds a plonker tbh. He repressurised the expansion vessel by the sound of it but if the internal diaphragm is shot repressurising it won't help for one microsecond.
If water is coming out of the overflow pipe outside thats because the PRV has lifted. Thats happens when there is too much pressure in the system. Typically they lift at 2½ - 3 bar. The trouble is that once it has lifted the seating gets full of carp wnad when the pressure reduces the valve doesn't reseat properly and it then passes. Whilst that is happening you have no chance of repressurising the system whatseoever. The simplest solution is to fit a new PRV.
You don't need leak sealer but what you will need is new inhibitor.
Oh and get yourself a different plumber - preferably one who knows what he is doing.
CheersThe difference between genius and stupidity is that genius has it's limits. - Einstein0 -
BlueMoonMole wrote: »without removing any case/covers from the boiler itself (as this does contravene Gas Installation & Use Regulation 1998)
CheersThe difference between genius and stupidity is that genius has it's limits. - Einstein0 -
thanks Keystone, have copied your advice to husband and will take your advice.0
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greyhounds galore - how did you get on?0
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Hi There, my combi boiler has been losing pressure and i have found a leak on the copper t behind the plaster, its really hard to get to and cannot access it easy, iv been reading about internal leak sealers that can be added to the system, does anybody have any thoughts on this stuff as it would solve a massive expensive leak?
Can i add this to my radiator through the blanking nut located at the top?
Hope someone can help or it looks like il have to take the wall out from the living room to the kitchen as this is where the pipe is located.
thanks guys0 -
Never used a leak sealer and never would myself. I'd want to repair the pipe properly to know it's been done right.
I know it's usually messy and requires some further putting right after, but I wouldn't be happy hoping the sealer has bodged the repair job for me.
Just my personal view of course. The sealers may well work but I recall comments on here in past posts about potential damage they can cause to the boiler. I don't know how true that is, but I'd always access the leak and do a repair.0 -
spitfire13 wrote: »does anybody have any thoughts on this stuff as it would solve a massive expensive leak?Can i add this to my radiator through the blanking nut located at the top?....................or it looks like il have to take the wall out from the living room to the kitchen as this is where the pipe is located.
Cheers
OH and BTW a new thread would have been more helpful to you as the title of this one doesn't reflect your problem.The difference between genius and stupidity is that genius has it's limits. - Einstein0
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