Standard old 1980's unpressurised system with open header/exp tank. If the system is left off to cool for even a weekend I get air in the system which seems to stick at the brand new pump, making it noisy and some rads don't heat up. Switching pump on and off a few times makes glug glug noises as the bubbles make their way to the header tank overflow. Once cleared all rads are piping hot.
Where does this air keep coming from?
Would chemicals in system reduce surface tension and prevent it anyway?
Cheers
Steve
Where does this air keep coming from?
Would chemicals in system reduce surface tension and prevent it anyway?
Cheers
Steve