Water hammer on 3 port mid pos

[splinterdream]

Hi

I have a customer who has water hammer as call for heating when hot water on. He informed me of this after i replaced his m/valve due to actuator failure and leaking valve but states his old valve used to do it too.

Has anyone else experienced this, not sure what to do for him.

Any help appreciated.

 

[Neil K]

Sounds like a valve shut. You sure it's not trv (s) making the noise?

 

[splinterdream]

He doesn't have trv's, strangest thing I've come across

 

[jtsplumbing]

Is valve connected correctly ? any other controls or valves on system, other option replace 3 port for 2 x 2 port valves

 

[dancinplumba]

Is pump right way round ?

 

[splinterdream]

Yes the pump is the right way and yes the valve is fitted correctly. I was thinking there may be an old non-return valve left on the system under floor or something. Have now seen there are some others that have posted a thread with a similar problem and resolved by installing a Danfoss paddle type valve. May try that. Thanks for your posts,