Plumbing Questions? Ask a Plumber for Answers ASAP
Do you have the make and model?
biasi activ A 120v
Are you able to run the pump with the centre plug out to release the air?
Can you hold the flow and return pipes on the boiler and tell me if they both get hot?
yes both pipes get hot one slightly hotter than the other
must go to bed, early start. will check in tomorrow.