baxi boilers.

[championc]

have a baxi 109e combi boiler the over flow seems to be constanty dripping and the water pressure gauge is up at 3/3.5 bar when the central heating is running? is it possible to over pressurise the system using the top up valve on the bottom of the boiler?

[buildersmate]

Yes it is, and that sounds like exactly what has happened. If you just used the filler loop until no more water would go in from the mains cold, you would have pressurised it to this figure.
These systems have to have a pressure relief valve, normally set at 6 bar but it could be (validity) set up to relieve pressure at a lower figure.
You should let water out of the system such that it is at 1 bar when at rest. It may rise a bit when hot and working - say to 1.5 bars - but it should not go higher than that.

[championc]

ok thanks.