Very very useful FAQ

My sealed system seems to have partially failed, ie I can keep it from going
over 3 bar by limiting the temp to 75C and keeping min pressure at about 0.4
bar.

I presume that the air will have leaked and needs pumping rather than the
diaphram holed - or am I just being hopeful!!

John


"Ed Sirett" wrote in message
news
On Fri, 13 Feb 2004 01:13:27 +0000, Shabs wrote:

OK I agree that the pump should be set to 3, but if i move the switch
into position 3 I can hear a sort of different noise, but when I start
the central heating from position 3, the boiler does not turn off,
just runs continuous and the pressure goes sky high. With the pump on
no. 1 the boiler does the stop-start stuff. How would i get the pump
onto no.3 but the boiler doing the usual stop-start routine.

It is very unlikely that setting the pump to the high setting will by
itself cause any problem.
You should now procede to tackle the cause of the high pressure directly.
See the Sealed system FAQ it is likely that as the _average_ water
temperature rises the system pressure is rising too quickly.
The cause for this is likely a failed expansion vessel.

The boiler will likely operate correctly once the water temperature has
stabilised but this may mean the prsssure will go even higher and water is
thrown out of the vent pipe.


--
Ed Sirett - Property maintainer and registered gas fitter.
The FAQ for uk.diy is at www.diyfaq.org.uk
Gas fitting FAQ http://www.makewrite.demon.co.uk/GasFitting.html
Sealed CH FAQ http://www.makewrite.demon.co.uk/SealedCH.html