How do i stop Water leaking out of air vent on Halstead ace combi boiler. System keeps dropping to 0. When I top up and raise pressure, leak gets worse before dropping to zero again over next few hours.

Patrick Connolly, November 2007

I've got the same problem with same boiler. My plumber says-- (1) Change the pressure relief valve, (the "3 bar" device), which is an easy cheap job. (2)--If this doesn't work there is a leak somewhere in the heating system. This can be a nightmare to find, but Fernox do a leak sealing additive so I'm going to try this next.

JohnC November 2007

John Cannell, November 2007

what do you mean by air vent?? if its the open ended pipe thats outside (15mm) then thats the prv and then that needs to be replaced of if its not that then its the expasion vessel? p.r.v is the red knob inside the boiler that says "3 bar" on it

ppan, November 2007