y plan clarity

[rainydays]

Hi all, trying to get up to speed on central heating wiring centre`s.

Looking at a SALUS diagram it shows terminals 12-boiler live, 13-pump live and 14-call from the cylinder stat all linked together in the wiring centre.

My question is: if it is a y plan fully pumped system with a pump not incorporated into the boiler would i remove the link between terminals 12 and13 and then link terminals 14 and 12?

The pump is next to the cylinder.

I would then connect the pump live conductor from the boiler into a termination in the wiring centre with the live of the pump.

My understanding is that the lp terminal on the boiler is a timed output to shift the hot water from the boiler.

Am i right or have i lost the plot?

 

[steptoe]

you may well have a boiler with a pump over run on it.

if so then you are correct in thinking the boiler controls the pump, is there also a permanent live at the boiler? it needs this to over run the pump.

 

[rainydays]

Yeah the boiler has connections for permanent live, S/L and L/P

Just found some info on the net that says that the timed pump over run comes from the permanent live through the PCB so i guess that answers my question about seperating them in the wiring centre