Banging TRVs.

[plumbandplumber]

Some of my TRVs make a banging noise. I have a pumpedsystem, with 3 port valve and 2 loft tanks. The valves are all flowing in thecorrect direction with the arrows on valve body – the valves are on the flowpipes into rads.
Should I try replacing the valves? If not, would it be agood idea to try a Grundfos Alpha pump that automatically varies it’s flow, ormaybe an automatic bypass?
Any suggestions welcomed.

 

[Sharp Point]

Auto bypass...

 

[Ray Stafford]

What make are the TRVs?

Is it an open vent or sealed system?

 

[drip-dry]

would say first thing to look at is make and quality of valves...you should always have a good by pass on the system...this is way systems should be designed and not just stuck in..designed systems,meeting the customers requirement make such a difference..

 

[plumbandplumber]

Thanks for your replies.

Ray Stafford>>>>> They're old Mysons.Open vented.

Just wondering why this started a while ago with one, then a couple more TRVs started doing it. Do the TRVs weaken/wear with age. Should I try new TRVs first, then bypass? Or go straight for bypass first?

 

[IDCHAPPY]

Old mysons won't be Bi Directional, if the TRV is on the return( switch the heating on and see which pipe gets hot first, that's the flow) it will struggle to shut as the pump is pushing against it.

 

[gav85]

if they are that old can't see them being bi-directional i have had valves chattering as they shut down on temp