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Martin Pentreath Martin Pentreath is offline
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Default Boiler dripping from pressure relief pipe

On Oct 17, 11:12*am, Ronald Raygun
wrote:
Grimly Curmudgeon wrote:
If the pressure relief valve is the spring-onna-wotsit-wivva-red-cap
type, try quickly rotating the cap so it reseats. Often a bit of system
**** will clag the seat.
If that doesn't work just replace it, they're cheap enough. Dripping
from these is quite a common fault.


If the relief valve is leaking, the system pressure should gradually drop..
Once a volume of water equal to that of the expansion vessel has left the
system, which at a steady drop should be a matter of hours or days, the
pressure should have gone to zero.

That the system is nevertheless still at pressure (the OP said 2 bar)
would, I suggest, seem to indicate that there is a leak in the manually
operated (and normally fully shut) mains water top-up valve.

Come to think of it, isn't 2 bar a bit on the high side? *Could it be
that the relief valve is actually doing its job perfectly, and that the
real problem lies *only* with the top-up valve?


Thanks to all. I think Ronald could have hit the nail on the head. The
system has been dripping for weeks without being topped up, but is
still at full pressure, so I guess is must be the top-up valve.letting
through. I shall make further investigations ...