Hi,
A while back I asked about a motorised 3 way ch/hw valve that was giving the symptoms of allowing ch when hw was called for.
I got the chance to test the valve from cold yesterday.
Removed the valve head Rotated the valve to the hw position Powered up the system.
I kept my hands on the pipe work either side of the valve (as far as I could from the valve itself) and felt both sides heating up nearly equally? ;-(
So, this suggests to me that the valve itself is faulty (damaged ball etc) and whilst I'm more than happy to change the entire valve body (it's on fairly short pipes that may need some 'persuading') it looks like the valve itself is secured to the face of the valve body with 4 screws and sealed with an 'O' ring and so, might be swappable with another / new / good unit?
Worth a go ... or what are the chances the valve seats are worn etc?
Cheers, T i m