Worcester 42CDi with UFH - Help needed please!

[slinkymcvelvet]

I have a 42CDI which is used for the usual, central heating and hot water. I am also adding UFH in my extention and have been trying to work out the correct plumbing and wiring requirements - it's been a headache.

The UFH is T'd off of the CH and consists of a pump and a juntion box (no wiring centre) and a Heatmiser PRT. Assuming the CH is ON and the PRT requires heat, it starts the pump. This is all very well and good, however many people recommend that this is treated as a seperate zone, with motorised valves. As I understand it this would allow me to start the UFH earlier than the CH.

The boiler thermostat is a TD200 with RT10. I believe I should put a motorised valve on both flows, after the T - Can someone please tell me how to wire this lot up and recommend some valves etc please? If the RT10 was 240v I'd assume it would be easy.. but its 24v(?)

 

[Agile]

You are correct except that the UFH loop runs its own circulating pump all the time that its timed for heating.

As you suggest the UFH is better on its own seperately timed loop.

I dont have time to write a book on how it should be connected but its relatively obvious.

You may find the suppliers have circuit diagrams to give you.

Tony