Hi.
I am slowly but surely getting the boiler (Vaillant turboMax) to be a happier one - not doing anything gas based, just sorting things like a loose NTC insert (screwed in tight but white bit spun and triggered F.1).
Anyway, all seemed to be going ok and I had read on here somewhere that they often work better on the lower side of 1-1.5 bar and mine was sitting a shade under 1.5 bar.
I thought (like a nit), that rather than bleed it from a radiator, I could lose the extra pressure AND check the PRV was a happy bunny by twisting the top.
It released a shade more than I wanted (quick thing) so I topped it back up via the filling loop, closed off both the filling valves and started it all up.
Pressure rose a tiny bit as it all warmed up, and everything was fab.
Later on, I went to check all was well and noticed pressure had fallen to about half a bar. Hmmm. Topped it back up and went to contemplate life the universe and boilers with a cup of tea. Back upstairs and sure enough pressure is heading South again.
Felt the PRV pipe and it was very warm - went outside and a saucer placed under the pipe had water in it when I next checked a few minutes later.
Have tried repeatedly opening and closing it (PRV not saucer) - letting it close gently and also "bang shut" in the hope it will re-seat. It won't.
Here come my three questions (sorry about the waffle), any thoughts welcome please.
1. Is there a simple way to generally make these seal again - or is it a case of "once they leak they need replacing"?
2. The valve looks a bit grim to get tools at - but there is what appears to be a spring clip around it. Is this a "fast disconnect / connect" system where I just but the correct replacement part, drain off surplus pressure and then five minutes later job done? Not seen this on other PRVs
3. Lastly, as I see Vaillant PRV's are about £30 including delivery. Can I simply put a generic 3 Bar PRV AFTER the Vaillant PRV? I cannot see that this would be dangerous in any way - but it might make a fairly grim task quite a bit easier to handle. If there is no safety issue (and I cannot see how there would be), then fitting a second, 3 bar PRV after the failed one would seem a simple and safe solution.
At the risk of irking people even more with a fourth question, is it generally a good idea NOT to test a PRV - on the basis that it would have very happily opened - but may not be all that keen on properly closing again. I have since found through googling, that it is almost unheard of for one to "fail shut" unless frozen, but they OFTEN fail to re-seal - as I now know.
Kind Regards & Thanks
Mark
I am slowly but surely getting the boiler (Vaillant turboMax) to be a happier one - not doing anything gas based, just sorting things like a loose NTC insert (screwed in tight but white bit spun and triggered F.1).
Anyway, all seemed to be going ok and I had read on here somewhere that they often work better on the lower side of 1-1.5 bar and mine was sitting a shade under 1.5 bar.
I thought (like a nit), that rather than bleed it from a radiator, I could lose the extra pressure AND check the PRV was a happy bunny by twisting the top.
It released a shade more than I wanted (quick thing) so I topped it back up via the filling loop, closed off both the filling valves and started it all up.
Pressure rose a tiny bit as it all warmed up, and everything was fab.
Later on, I went to check all was well and noticed pressure had fallen to about half a bar. Hmmm. Topped it back up and went to contemplate life the universe and boilers with a cup of tea. Back upstairs and sure enough pressure is heading South again.
Felt the PRV pipe and it was very warm - went outside and a saucer placed under the pipe had water in it when I next checked a few minutes later.
Have tried repeatedly opening and closing it (PRV not saucer) - letting it close gently and also "bang shut" in the hope it will re-seat. It won't.
Here come my three questions (sorry about the waffle), any thoughts welcome please.
1. Is there a simple way to generally make these seal again - or is it a case of "once they leak they need replacing"?
2. The valve looks a bit grim to get tools at - but there is what appears to be a spring clip around it. Is this a "fast disconnect / connect" system where I just but the correct replacement part, drain off surplus pressure and then five minutes later job done? Not seen this on other PRVs
3. Lastly, as I see Vaillant PRV's are about £30 including delivery. Can I simply put a generic 3 Bar PRV AFTER the Vaillant PRV? I cannot see that this would be dangerous in any way - but it might make a fairly grim task quite a bit easier to handle. If there is no safety issue (and I cannot see how there would be), then fitting a second, 3 bar PRV after the failed one would seem a simple and safe solution.
At the risk of irking people even more with a fourth question, is it generally a good idea NOT to test a PRV - on the basis that it would have very happily opened - but may not be all that keen on properly closing again. I have since found through googling, that it is almost unheard of for one to "fail shut" unless frozen, but they OFTEN fail to re-seal - as I now know.
Kind Regards & Thanks
Mark
