generic pump in combi

[Groovejet]

My friend has baxi 105instant and it has been fitted with salus pump with same pressures.
The boilers been creating loads of air an noise and cutting out after 10 sec when using hw.
Auto air vent is closed cos it leaks and the expansion v is ok.
Can the generic pump cause problems ie rotor sticking due to incorrect fit or incorrect pressures.
Thanx

 

[Dan Robinson]

More likely, the impeller is not the correct dimensions for the pump body.