My Britony Combi SE 80 keeps losing pressure, when I boost it with the filling loop its ok for a short while but soon drops again.

I have noticed that when there is demand for hot water and/or heating that the overflow pipe is leaking water.

When the HW is on it constantly cycles through hot-cold-hot-cold-hot-cold etc etc.

Last year it had a new pcb and diverter valve plus a couple of other bits but has never really worked properly since (we lost faith with the plumber at that time after nearly 3 weeks of changing parts) but I'm fed up with having to use the electric shower to fill the bath!

Please can anyone help?

Ian, June 2009

or leak on raidator

lego, July 2009

dripping is probably expansion vessel, observe guage when hot ie heating on for a long period if its reading near 3 its a cert. if it drips all the time whatever temp, maybe just prv.

hot water sensor? giving hot/cold

x, June 2009