When the heating is on, water drips quite rapidly from the overflow pipe outside and so the pressure drops. There is also a small drip coming from inside somewhere. Help!!!!

Rosie, January 2010

the diafram has gone in the switch over valve this allows the boiler switch from heating to hot water when the tap is opened they is a hole in the diafram so you have got water going throw diafram on to the heating side if you look at your pressure gauge it probley high call a plumber it not a easy job

geoff, January 2010

baxi combi 105e light comes on for fault onfan on flue how do i mend it

d/ crabtree, January 2010

bet ya last dollar small drip is from hot water diaphragm assembly if it drips out front left hand side,rhs drip would prob be pump airvent or pump seals.
if when the pressure drops after youve used heating like you said and you top it up to say 1 - 1.5 bar (normal) then fire the heating away again and guage rises beyond 3 bar and drips outside then you have a flat of fooked expansion vessel, prob fooked im afraid and depending on boiler location could be a boiler off the wall job to replace but it will need looked at to confirm what actions are required.

ste, January 2010

i dont know the boiler but what was sequence of events? - could it have been that the pressure was originally low and someone charged up the system via filling loop?if so it sounds as if it was overpressured - easily done - and the excess pressure may have put additional pressure on 'possible' jubilee clips that clamp flexible pipes within boiler -these will require tightening up if this is so - but firstly check that the filling loop valves have been shut off after charging the system else the system will continually charge up and excess pressure is then sent to outflow - sometimes these valves become defective and cannot fully shut off water charging system and will need to be replaced - let us know if we were correct in first instance

eddie, January 2010