M
Mork
Hi all, just installed a polypipe under floor heating system to an existing Y plan, the valve is a V4073A,with this system the UFH stat should independently operate the UFHeating from the existing central heating, the snag is with the time clock off and the UFHeating stat on both the UFH & the central heating come on, I've checked the wiring and I know Im back feeding the orange of the zone valve, but it appears that this in turn is back feeding the white (heating on). Q; Does this valve allow for back feeding? Is the valve itself at fault? Many thanks if you can help, cheers Mork.