Wiring in Underfloor Heating

[Stanios]

Hi guys got a Honeywell evohome to wire up tomorrow, rads on one zone, hot water and third will be underfloor. The underfloor is only for kitchen so its one zone. Thing is ive never wired underfloor, what I was going to do is just wire in a stat to the motorised valve to underfloor manifold + the pump on manifold so when stat asks for heat it will fire them up.

What confuses me is that there are two cables already on the manifold (aside from the pump cable), I dont think there are any actuators since its just one zone. What do those cables do? In a wiring manual i found online it shows one manifold cable and its wired exactly like a room stat at the wiring centre(save for neutral connection) but there is nothing about the second cable.

 

[Stanios]

What are the two wires coming out of that box? Any help would be much appreciated. Cheers

 

[dancinplumba]

There is a temp sensor in box, one wire goes to pump and other wire goes to a room stat

 

[Stanios]

Ah yes that makes sense.. Do i take the existing pump wire (the black one) out and wire pump to manifold via one of the white ones?
Cheers mate

 

[dancinplumba]

Yes, take power to it as well

 

[dancinplumba]

Ideally there should be 3 wires, power in, pump and stat wire

 

[Stanios]

Yeh just realised both cables are 3 core so the third cable you mention is missing. Gona have to hand it over to the underfloor guy. Thanks for your help dancing