Plumber required

[Herminator]

below the 2 pumps it looks like there is a bypass valve, is this open ?

The one on the floor or the one between the two pumps on the wall?

 

[Taz]

not the 1 on the floor

if the valve directly below the pumps is open it could be that either pump running will draw through both pipes, the pipe on the left is the hot water tank, if the pump on the riight is the return from the heating then it will be drawing through that too

which pump is running?

 

[srhutch]

Under normal circumstances I would expect the tap between the two pumps to be closed. If one pump failed that tsp could be opened to share the pumping between water and heating circuit.

The tsp on the floor serves no purpose as there is another further up the pipe doing the same job.