Honeywell Diverter Valve V4073A1039 Problem

[Jacko439]

I have a Honeywell Diverter Valve Pt. No V4073A1039 which is programmed by a Honeywell ST9400C on a fully pumped system. The problem I have is that when the programmer is calling for central heating it stops the hot water programme from switching on even though the green on light on the programmer is showing, the moment I switch off the Central heating side the hot water switches on.

[beegeebee]

No idea really, just to say in the 20 years I've lived in this house, have had the 3way valve replaced on three separate occasions. For reasons unknown apart from the fact they would not respond to the programmer. Sorry I'm no help to you.