vent pipe to header tank

[Archbold]

Hello my first post strange problem when central heating switches on the vent pipe from header tank starts to vibrate the pipe is not moving but when you put a hand around it you can feel vibration been running well for 5 years this has just started last few weeks.had plumbers out and also gas board no one has a clue what the problem is system all working fine rads and hot water all pipes correct new pump fitted.noise is driving me up the wall can hear it all over house it only lasts for 2-3 mins any ideas anyone.

 

[nysk2008]

tried turning pump speed down to see if that sorts the prob, as you said new pump fitted, was it like for like?

 

[Archbold]

Yes like for like have ran pump on speed 1 this does make noise a little less noisey but not much also rads downstairs slow to heat norm pump speed 2

 

[Whn1]

When does it happen?

 

[bewsh]

is the pump running dry?

 

[Archbold]

happens when room thermostat calls for heat and when hot water tank stat calls for heat. pump not running dry

 

[Whn1]

Have you checked the motorised valve?

 

[Whn1]

Or auto bypass if it has one?

 

[Archbold]

y plan valve only 6 months old honeywell no auto bypass great response to problem by the way

 

[stevetheplumber]

plastic clips gone slack or popped out ?trv sticking?try removing all the heads see if it stops it