Air in System

[ploughback]

Usual story of air in an open vented system which appears to be being sucked in evry time the system is in operation. Ive tried tightening all compression joints and tied up the ball cock in the tank to prove no water being lost. Could it be sucking in from elsewhere? Anybody any ideas?
One plumber suggested isolating & pressurising the system to force weak point to show itself - sounds a bit drastic to me. Also considering auto vent but isnt this just masking problem?

Cheers

Tom

 

[Slugbabydotcom]

Read my post HERE About the possibility of air being dragged in through the pump itself.
Also possible that air is getting dragged in through a rad valve which is under negative pressure when the pump is running.
Condition is sometimes referred to as a micro leak where the hole is so small that air can get in but water cant get out

 

[ploughback]

Thanks for that, I will check out pump next....