Thumping noise in Vaillant Ecotec Plus 618

[RobertigK]

We’ve had a problem with our boiler, a Vaillant Ecotec Plus 618 model off and on for the best part of three years now

It makes a thumping/whooshing noise, a bit like those balls that you get in a tumble dryer and the pressure needle goes wild so much so that we turn it off fearing something awful’s going to happen.

The person who fitted it added another pump, about six inches underneath the boiler, explaining to us that though the boiler had its own internal pump, it needed another to pump a round a house of our size. Our house is just an ordinary suburban semi but the boiler is in the loft. Ironically, it was only when this pump was replaced last time did the boiler stop thumping. Now almost two years on it’s started doing the same thing again.

The installer’s been round but can’t fathom what’s wrong. My betting’s on the pump which is too damaged to pump the water around quick enough and the boiler’s overheating. Though of course I'm no expert.

Grateful for any advice you can give. Is the extra pump the problem and if so why and should we just remove it altogether? If we have to put in another pump what’ll stop this happening again?

 

[picasso]

ask your installer if he has opened the automatic air vent on top of the boiler pump and you shouldent need a second pump in a 3 bed semi.

 

[mickyg]

sounds like the heat exchanger could be partially blocked, or it is possible its the pump or a restriction but normally this would result in a fault code . You shouldnt need an extra pump on the system the one in the boiler is more than adequate.