boiler presure problems

[Clive Sparks]

I have a Vaillant ecoTEC 428 boiler which has been losing pressure for about a year now and it has been necessary to re fill once a week. I could find no leaks on the system but water is obviously going somewhere. I had a heating engineer work on the system and replace a failing pump about this time last year and he said it’s evaporating in the boiler as the heat exchanger was corroded and I should consider a new one or maybe a new boiler. I am an electrician but my plumbing skills are somewhat limited however this sounded like an excuse to get me to part with some big money as surely this is not scientifically possible? I have been putting up with problem since then however it has been slowly getting worse and its now every day. I now see a green residue build up on the pipe outside in the garden leading to the pressure valve pipe over the boiler. I guess this is letting by and is where the water is all going. I went to my local plumbers’ merchant with a picture of the valve and said I wanted an exact direct replacement but was told that I needed to provide details and specifications of the boiler as a this was an unusual part Blah blah. As I said, my plumbing skills are basic, but I figured untightening two compression joints and replacing like for like, seems the best option for me.

Can anyone tell me what this valve is and where to get one?

Many thanks

 

[Iamchamps]

I had similar problem was losing pressure found no leaks so as advised here tie a bag round the release pipe which over a few days filled up. The plumber who fitted the boiler returned and in his words "blasted" the valve but letting water out filling up and letting water out about 7 or 8 times when I mean letting water out I do not mean all water in the system just a few small bursts. After this it has never leaked since. He said the valve sometimes gets small amounts of crap stuck inside causing it not to fully close by blasting it this cleared and now closed fully.

 

[terryplumb]

your prv is letting water out for sure.the question that you have to ask yourself is why. is it doing its job to release excessive pressure in the system , the reason for its existence ? or is it allowing water out for no good reason ?

 

[Terrywookfit]

..

 

[dilalio]

...

 

[Clive Sparks]

your prv is letting water out for sure.the question that you have to ask yourself is why. is it doing its job to release excessive pressure in the system , the reason for its existence ? or is it allowing water out for no good reason ?

Well thanks to the Terrys, I was kind of asking you professionals why coz I don't know! Thanks to lamchamps, I'll try that.

 

[dilalio]

I had similar problem was losing pressure found no leaks so as advised here tie a bag round the release pipe which over a few days filled up. The plumber who fitted the boiler returned and in his words "blasted" the valve but letting water out filling up and letting water out about 7 or 8 times when I mean letting water out I do not mean all water in the system just a few small bursts. After this it has never leaked since. He said the valve sometimes gets small amounts of crap stuck inside causing it not to fully close by blasting it this cleared and now closed fully.

But be warned that some, once activated, will not reseat again!

 

[terryplumb]

Clive ,to establish if the prv is lifting due to excessive pressure ,which is a sign of a problem elsewhere , turn c/heating on full .note the pressure on gauge when cold, then monitor the gauge over say an hour. if gauge rises to around 3 bar ,then the prv is supposed to lift ( open and allow water out ).