My combi boiler is dripping/ running water when in use. It appears to be coming from a valve attached to the pump - this could be to let out air build up?

Had a plumber out and problem did not show itself in his presence (pressure in system had fallen extremely low), so he couldn't fix it. He topped up system and it was OK for a week. Now it's doing it again.

Any suggestions?

RachelB, May 2005

OK, I'm no plumber but I had a similar problem with a Sime Super 90 Plus. It was dodgy when we bought the house (we didn't know) and it got progressively worse.

The problem was the 'Exchanger' - it was corroded beyond belief - ot was so bad that slowly water leaked from it, bringing the pressure right down. Eventually we were at the stage where everytime I topped the pressure back up, the Exchanger would leak worse than the time before.

This therotically is a time bomb, waiting for it to go 'bang' with a fair force.....

The solution was to get a new Exchanger - this cost us about £100 plus labour.

I suspect that your problem is the same, but your in the early stages at the moment. The Exchanger looks like a small tank when you take the front cover off.

Hope this helps, but I may be completely wrong....

Gavin Sever, May 2005