Air lock in central heating return?

[Bill Wright]

Fred

[Fredxxx]

The OP has already said that the pump spins easily, so not stuck.

However your suggestion does work in many cases.

[charles]

and, if there is sludge a tap with a hammer will often dislodge it.

[Slough]

My plumber has investigated the problem and reported back. Compacted sludge was found in the heating return pipe to the boiler. This had led to a lot of air getting into the system.

The sludge was removed. System re-filled. Heating is now up and running again.

Thanks to everyone for their feedback. It enabled me to eliminate the system components as the cause of the problem and reassured me that I had done everything within my capability before calling in a plumber.

[www.GymRatZ.co.uk]

My first house had a single pipe central heating system. There was a chipboard lid on the header tank and it was all run from a solid fuel parkray fire back boiler.

I ended up having to connect my diving cylinder to sections of pipes to "clear" them of wood blockages where the chipboard had deteriorated and worked it's way around the system before converting to a 2 pipe F/R system that actually worked.

There's no accounting for what atrocities and poor system designs are out there.

:)

[Dave Plowman (News)]

Now add inhibitor to prevent it happening again.