I have an unvented Vaillant condensing boiler which is regularly losing
pressure - I guestimate te loss to be of the order of about 3 pints per
week judging by the length of time I have to open the valve on the
filling loop. (The gauge on the boiler falls to zero and said boiler
starts to make strangulated noises...)
This has been happening all summer, ie with the CH switched off. I
can't see any leaks anywhere, and the tundish by the pressure relief
valve is dry; but logic tells me the water must be going somewhere, and
surely at this rate ought to be detectable. Where's it going?!
Already have actually! Decided it couldn't be the expansion vessel
because the pressure only drops, it doesn't cycle (have I understood
that correctly?); and the pressure-relief valve seems OK as I said. And
I'd have thought I'd notice the effects of the volume of water which is
apparently vanishing... so I'm stumped!
Thanks Ed. Well, I thought I had had a good look... the pipework twixt
boiler and HW tank does pass under the upstairs floor for several
metres, and I haven't pulled up carpets to inspect that; but you'd think
that level of leak would have manifested itself, wouldn't you?
Mm, maybe that's where I'm headed; seems a bit of a bodge solution though?
Because my problem is not tied to the central heating being on?
Presumably I just need to be looking at the boiler/HW tank/intermediate
pipes, is that right?
On Sat, 09 Sep 2006 21:03:07 +0000, Lobster wrote:
No. All the primary pipework ( that includes the rads) are under
pressure, although some types of leakage happen only when the pipes are
IME you can loose a litre or two a week and not be flooded out, look
carefully for damp patches. Assuming its not the relief valve itself then
the most likely places are:
1) The radiator valves.
2) The boiler
Ed Sirett - Property maintainer and registered gas fitter.
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