Worcester combi + Underfloor heating

mff369 · May 25, 2011

Hi,
Can anyone help me regarding wiring combi with underfloor heating master wiring centre. I have always ran a feed direct to boiler from fused spur,then the same to the master wiring centre.
Could I power the boiler from the wiring centre so only having the one spur? If so how ?

truckster · May 25, 2011

I don't get why you have two spurs but depending on the layout you can feed the master wiring centre and take the boiler feed from there which is probably easiest with a three pole switch at the boiler point for servicing.

Short Circuit · May 25, 2011

mff, it might sound a bit daft, but what you need to do is power the wiring centre from the LS on the boiler. You will have the permanent supply at the boiler for water, and then from the LS - take that to supply the lives in the woring centre,and again from the LR in the boiler, you need to take that to the wiring centre too, and have that on the boiler relay! Which wiring centre are you using? If there are volt free contacts, the LS will in effect put the supply to one side of the volt free part, when the circuit is made, the contacts will supply the UFH pump and the boiler relay!

Dont forget that if you are using 'normal' heating upstairs, wire the upstairs stat to where the zone valve is and not the wiring centre.

I would use two spurs as well, but not 2 supplies, only so there is a local means of isolation for maintainence etc - hope you cna understand that, its not easy to explain!