Low pressure but where’s filling loop??

[Siobhan]

Very good then, I think that "proves" that the PRV is fed from a tank, and is wide open, last test, if you wish, just close the black valve fully and see what happens to the pressure(s) I think your boiler has a 10 litre E.vessel so would expect to see a rise/fall of ~ 0.5/0.7 bar between hot/cold if no expansion is passing back through the PRV. (maybe that's why the pipe was warm)

Sorry for my ignorance, to close the valve do I lock it clockwise or anti? The lower part of the pipe is now cooled quite a bit and the pressure gauge is at 0 (the gauge on the boiler is at nearly 0.2)

 

[John.g]

To close the water supply off you shut the black valve clockwise. To try and increase the pressure open the black valve anticlockwise and screw in the adjustment screw clockwise, the pressure will then increase if mains fed.

 

[centralheatking]

The tanks are identical but the one on the right Has a ball valve and seems to be fed by the mains, the one on the left has a pipe from overhead that drips into it - this pipe goes down behind the hot water storage tank in the hot press, maybe to downstairs where the boiler is but I can’t see.View attachment 41873View attachment 41874View attachment 41875View attachment 41873View attachment 41874View attachment 41875
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The PRV beside the hot press that’s showing almost zero pressure? Not sure what it’s doing there but the pressure rises slightly when the heating is on (the same as the pressure gauge on the boiler)

However I can’t see anything that looks like a swing or poppet valve near the cold water tanks - is that where I would find this?

This system seems a normal vented set up ..its a real puzzle ..chking
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This system seems a normal vented set up ..its a real puzzle ..chking

anyway we are off to North Cornwall for a few days soon , to stay in my last property there
before we buy my forever home in West Cork.then its hello Holyhead ferry terminal uck
..centralheatking

 

[Siobhan]

This system seems a normal vented set up ..its a real puzzle ..chking
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anyway we are off to North Cornwall for a few days soon , to stay in my last property there
before we buy my forever home in West Cork.then its hello Holyhead ferry terminal uck
..centralheatking

Sounds like a great plan, enjoy and thanks a million for all the help!
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To close the water supply off you shut the black valve clockwise. To try and increase the pressure open the black valve anticlockwise and screw in the adjustment screw clockwise, the pressure will then increase if mains fed.

Ok I’ve just done this now but nothing happened. It’s a mystery alright! Thanks so much for all the advice, even if the problem hasn’t been solved o e learned a ton and can now face a plumber with some idea of what they’re talking about!

 

[SJB060685]

To be honest what/however this system is configured it's going to baffle most

 

[John.g]

And the final pressures?

 

[Siobhan]

And the final pressures?

There was no change to the pressure when I adjusted the PRV - 0 when the boiler is off, nearly 0.5 when on for nearly an hour. Rte boiler gauge is 0.1 or 0.2 when off, nearly 0.5 when on.