Page 1 of 1

S-Plan wiring with boiler switched live return

Posted: Fri Oct 05, 2018 9:05 am
by Keith.L
I have an S-plan system, regular boiler (Worcester Bosch Greenstar Ri) and external pump. I had anticipated using the wiring diagram on page 46 of the installation guide but am puzzled about how to deal with the demand / live return to the boiler. The boiler requires that the pump is wired directly to it rather than via the wiring centre (Honeywell 10-way), no problem there but I don’t know which terminal in the junction box illustrated on page 46, that the live return connects to and if it requires any changes to the illustrated layout as a consequence?

Update - I've worked it out (you can tell I don't do this for a living!) - the switched live connects to terminal 10, shared with the orange wires from the two zone valves. All other wiring on page 46 remains the same except for the pump, the live for which is taken from the LP connection in the boiler itself and not through the wiring centre.

I'll leave this up for a bit in case this is useful to anyone else.

Re: S-Plan wiring with boiler switched live return

Posted: Mon Oct 08, 2018 2:36 pm
by Richard
Hi Keith,

Yes unfortunately the Page 46 diagram is a bit out of date verse up to date systems with pump over-run.

Glad you worked it out.