Flow hammer on 3 port honeywell valve

[gassman]

Problem only occurs when HW and CH on demand then CH satisfied. Hammers for 2-3 secs on mid pos shutting off heating. All other options no noise at all. Netatec system boiler and the cylinder circuit is still 28mm off original gravity run, with manual vent at the cylinder so no trapped air. Any ideas?

 

[Destroyer2813]

Had this once b4 same syptoms as you turned pump speed down sorted it, happened after new boiler installed. If h/w on gravity still why there a 3 port on it should all be pumped surley

 

[gassman]

Yh it is fully pumped with 28mm pipe on the cylinder run, 22mm on heating. Like your idea of pump speed, do you know if it can be adjusted on the Netatec boiler with its own inbuilt pump?

 

[SafeGasInstall]

what make is 3 port valve ? could be to sludge in it , stick a auto bp

 

[mitchellcook]

I had the same problem the other week mate. In the end I changed the valve to a danfoss which is the paddle type. Think the ball was banging back and forth on the old 3 port.

 

[gassman]

System is clean with Honeywell mid-pos valve, only 8 months old. Auto bp is ok

 

[SafeGasInstall]

Auto BP shoud take the flow if balanced correct

 

[gassman]

Changed the valve for a paddle type, all running sweetly now