Grundfos noisy oil central heating

[Donzagabonza]

Hi. We have a wolf oil central heating system, with a grundflos alpha 2 circulation pump. Sometimes it makes a tinkle noise ( like metal to metal) and sometimes not. With and without burner running. I removed pump and impeller is ok and clean. Bled system through. Nothing helps.

 

[John.g]

Possibly new pump required, how old is this one?.

 

[Donzagabonza]

Possibly new pump required, how old is this one?.

A good few years I suppose. It was in the house when we got it, 4yrs ago.

 

[John.g]

Would expect a bit more than that, maybe worth looking at the settings and power W and m3/hr, if something like this one.