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Another boiler losing pressure

Postby toplondonchef » Tue Nov 16, 2010 9:23 pm

Have a similair problem to the previous post submitted by jrterror;

I also have a boiler fitted in the loft, a Worcester Bosch Greenstar condensing. It's been losing pressure for a couple of weeks now and I have been repressurising it to 1.5 bar every 2-3 days
It's now losing all pressure and reading zero after 1-2 days and when at zero, the boiler doesn't run. A couple of times now we've had no hot water or heating early in the morning as the boiler must have lost all pressure during the night
Over the weekend I added 2 ltr of liquid leak sealer to the system, after following instructions and allowing up to 24 hours for the product to work.
It appears not to have solved the leak as again the system is on zero and again no heating/hot water until repressurised
I've checked all rads for obvious leaks and cant find any, no damp patches on ceilings/walls but obviousely ground floor pipes are under the floorboards
I had most of ground floor covered with Amtico flooring this year and this is bonded onto self leveling compound, then 12mm plywood, then floorboards.
The thought of the floor having to come up is not a pleasant option
What is my next option ?
I brought leak sealer from Toolstation and it's made by Eco - is it any good compared to other makes ? The guy behind the counter told me that they sell loads of this stuff to all the plumbers - so gave me some confidence
Just out of interest for a boiler to lose pressure from 1.5 bar to zero how much water loss are we looking at - pints, gallons ? (it repressurises in seconds)
Also just noticed in boiler fitting instructions it says "the addition of sealing agents to the system water is not recomended as this can cause problems with deposits left in the heat exchanger"
Have I caused another problem by adding leak sealer?
Any advice given will be very much appreciated - Thanks
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Simply Build It

Postby DEEARR2 » Wed Nov 17, 2010 11:56 am

Have you checked for signs of leaking from the external pressure relief pipework. This is located outside usually in the vicinity of the boiler.
It would be advised to flush the system clear of the sealing agent in that this use is against manufacturers recommendation and that it had no effect on the problem.
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