Just replaced 5 rads in a heating system,removed and flushed the rest of the rads,flushed system replaced all the rads and added inhibitor.Reason for this was a noisy pump and air in sytem ie bleed all rads next day air in rads again. Upon inspection i found that the F&E expansion is sucking air then releasing and in the F&E tank every 5 or so seconds water is pushed back into the tank,heating pump seems as thogugh its pushing or pulling then slows then pushes or pulls again then slows! Any ideas to resolve the problem?
