Air in system

[JohnnyCarpenter]

Hi I have an ongoing problem with air (2 + rads full of air each day) I have fitted various bleed valves which help but dont fully sort problem. I believe the air comes in through the pipe that overflows back to the header tank when the pump turns on and off. Heat comes from an open wood fire with the pump on the return side of the system.
My thoughts are to extend the overflow pipe below the surface of the water in the tank, that way excess water will still go into the tank but only water can then be pulled back (no air)
Will this work or am I missing something?
All the best
Johnny

 

[GasmanxxxR1]

The configuration of the pipework is probably wrong. Cold feed in relation to open vent and pump probably needs looking at.

Extending open vent ito water is not a cure for the problem

 

[Simon F]

Hello Johnny,
what height is the vent pipe above the water line?
what speed is the pump set to?
might be corrosion causing production of hydrogen gas, not air