Hi all central heating experts. Can I pick your brains please?
Central Heating programmer recently changed from Switchmaster 400 to Danfoss FP715si. As far as I am aware the main difference between the two is that the Danfoss allows individual control of HW via the HW off signal missing not used on the Switchmaster
Since the change I notice that when HW and CH are both on, the mid position valve buzzes/rattles/vibrates (cannot really describe the noise). Once HW achieves set temp and I guess, shuts off, the noise stops.
I assume that with the Switchmaster it wasn't present cos both HW and CH were not independent but wonder if the valve is perhaps so old that now it does work independently, the valve does not like the change?
Can anyone advise cause of problem? Could it be simply replaced or is it a wiring or voltage/current issue? I have checked the wiring (Y plan) and it all seems to be correct, the system is operating correctly. Obviously do not want to purchase new and then find prob is still there.
Also any ideas on best place to obtain replacement other than Ebay?
Or can you suggest an alternative to the Honeywell?
Many thanks plumb people, I would appreciate your help!
Cheers
Central Heating programmer recently changed from Switchmaster 400 to Danfoss FP715si. As far as I am aware the main difference between the two is that the Danfoss allows individual control of HW via the HW off signal missing not used on the Switchmaster
Since the change I notice that when HW and CH are both on, the mid position valve buzzes/rattles/vibrates (cannot really describe the noise). Once HW achieves set temp and I guess, shuts off, the noise stops.
I assume that with the Switchmaster it wasn't present cos both HW and CH were not independent but wonder if the valve is perhaps so old that now it does work independently, the valve does not like the change?
Can anyone advise cause of problem? Could it be simply replaced or is it a wiring or voltage/current issue? I have checked the wiring (Y plan) and it all seems to be correct, the system is operating correctly. Obviously do not want to purchase new and then find prob is still there.
Also any ideas on best place to obtain replacement other than Ebay?
Or can you suggest an alternative to the Honeywell?
Many thanks plumb people, I would appreciate your help!
Cheers