Britony Combi boiler leaking from top of 3 way valve

[andy1972]

I noticed a leak in the l/h hydraulic block, I bought a new part and replaced it myself which went ok, but it didnt come with the seal to seal it to the exchange. I didnt see any on the old one, althought they were they, I called the usual boiler guy out and he replaced them. After he had replaced them there was a leak from the other side of the boiler, near the other side of the exchange. The boiler was running fine but the pressure was upto 4 bar I didnt know why, i tried drianing some off but it kept going back up, then i noticed he had left the tap open on the flex pipe which tops the boiler up, i closed it and then was able to drain off the pressure to 1 bar. but now i have water leaking out of the top of the 3 way diverter valve, i'm going to replace the seal to see if that the problem, but i'm not sure if having the boiler full to max would have damaged anything else.

 

[Agile]

Overpressurising should make the pressure relief valve open at 3.5 Bar. Yours may be jammed which is potentially dangerous.

Over pressurising risks causing leaks inside the boiler and bursting the rads!

Tony