PLEASE HELP ME - AIR NEAR MY CENTRAL HEATING PUMP

[Millsy 82]

Could a blockage be checked by draining down say 10 litres of water and observing if the F&E Tank ball cock starts to make up rapidly??

You could do wouldnt telk you where the blockage is though.

 

[John.g]

What I was trying to say (badly) is if the make up is rapid then it would point possibly to no blockage and problem possibly elsewhere, will be interesting to see if reduced pump head helps to alleviate noise problem, OP said in first post that all rads are heating up ok.