Ask a tradesperson


Air sucked in through vent pipe on central heating

I have an open vented system in which I recently changed the pump, even on the pump lowest setting air is being sucked in through the vent pipe. The setup looks like this: (please ignore the dots )

II . . . .vent into loft
II. . . . II
II . . . .II
II . . . .II
II . . . ..==========
II . . . .II. . . . . . .II
II. . . . II . . . . . .II
II . . . .II . . . . . PP (pump into 3 way)
cold . . II
feed . .II

There is about 1 metre between the cold feed tee and the pump tee (the pump is above cold tee), there was a block in the cold feed pipe which was replaced and drains freely ? Is this piping incorrect causing air to be sucked in ? Can this be fixed by moving the cold feed tee above the pump ?

Any advice greatly appreciated.


2 Answers from MyBuilder Plumbers

Best Answer

Should be in this order
Vent, Feed, Pump and within 150mm of each other.
Common fault would be blocked cold feed usually where it tees into the flow/return. Can check with magnets have a google.


Answered 28th Jan 2015

Quality drawing!!


Answered 29th Jan 2015

Post your job to find high quality tradespeople and get free quotes

Can’t find an answer? Ask a new question

Question Categories