Recent content by JackF

I have a fully pumped open expansion tank system . At high or medium pump speed it is sucking in air but if I turn it down to lowest speed it stops sucking air. Any idea whats wrong.

I have the same sound coming from my pump and it is sucking in air but when I turn the pump speed down to the lowest It stops the surging noise and the system remains clear of air after purging. The problem with this is it takes a lot longer for the rads to heat up and some stay cold at the...