Why Does My Hot Water Circulating Pump Bang When It Starts Up?

[Brian]

I have recently had a new boiler and circulating pump installed keeping the hot water cylinder. I have the hot water timer set to come on for an hour each morning but when the time is reached, a loud bang comes from the pump which can be heard all over the house. Can anyone please suggest what the problem is and how to cure it? If it is not a simple job, I will call the installer back to attend.

 

[Brian]

Update. I have had the installer attend. He has made some simple adjustments to the pump and now, all is well. Thank you all for trying to help.

 

[John.g]

Good to hear that, if you don't mind you might post the present pump power and if possible the pump setting.

 

[Brian]

Hello John. I am not really sure about the settings. All I can say is that there are two buttons. The one on the left is set to Auto and the one on the right which has a Moon/Sun symbol, is on the lowest setting. The dial reads 14W when it first comes on, but varies as the heat goes through. Hope that makes sense. Brian