Zone valve wiring into existing CH system

[DP]

Y plan CAN be used for UF heating

A 3 port Y valve does not spring closed - You have to drive it to the shut water position by giving it a "hot water off" signal from the timeclock, and a "hot water satisfied" from the stat.

A 3 port valve does spring to close position (with exception of MOMC valves) of CH port. In HW mode it does not need to close only remove the signal to heat source. If CH calling, then HW satisfied OR HW OFF will motor the valve to close the HW port

 

[matt1e]

Y plan CAN be used for UF heating

A 3 port Y valve does not spring closed - You have to drive it to the shut water position by giving it a "hot water off" signal from the timeclock, and a "hot water satisfied" from the stat.

A 3 port valve does spring to close position (with exception of MOMC valves) of CH port. In HW mode it does not need to close only remove the signal to heat source. If CH calling, then HW satisfied OR HW OFF will motor the valve to close the HW port

true it could but why would you?
it would require an extra cable core to the room stat on one of the zones
the wiring is more complicated, and if the boiler switching is volt free then unless you are using a dedicated UFH controller that may have voltfree enable terminals you will need to add a relay to fire it
2 ports are the best option
Matt

 

[FirmButton]

As it happens I have two two port valves so an s plan would work for me but I am unsure as the best way to wire it. Currently there is a combi boiler and manual room stat. Now I have fitted a ufh manifold, it has voltage free contacts. Can you knock me up a simple diagram on how you would wire it chap?

Cheers

Steve