Water dripping from pressure relief valve

[T-maker]

Hello, I have a glowworm 30ci combi boiler which was serviced a couple of months ago. Its operating pressure is 1.1 bar. Just recently it's started to lose pressure. Every 3 or 4 days i've had to open the filling loop. I was fearing the worst that there was a leak under the floor somewhere but i've noticed its dripping from the pressure relief pipe outside. It now is a drip a second and requires filling every day sometimes twice. Can anyone tell me why its dripping from here? And is it an easy fix? Thanks in advance.

 

[Burnerman]

These things are notorious for not sealing once they've been opened - which is why its a bad idea to depressurise the system from them.
If you're happy with opening the thing by yourself, the debris within may be shifted, if your luck is in....more often than not its time for a new one.
John

 

[T-maker]

Thanks burnerman, so do you think that when it was serviced, the system was depressurised from this relief valve and not through the brass tap fitting underneath the rad by the front door, if you get what I mean!

 

[Burnerman]

Its certainly possible, especially if the expansion vessel was checked for its air pressure at that time.
More often though, people overfill the system via the filling loop, and once the pressure reaches 3 bar, the prv lifts automatically.
John

 

[T-maker]

that might have happened to be honest. my missus rang me at work when it locked out and I gave her instructions. I think my instructions were good but the boilers got a crappy digital pressure gauge which doesn't register till it's too late. Luckily i got the feel for it but my lady...... . Anyway thanks very much for your help.