bosch combi and honeywell stat and programmer

[daz1963]

Hi all. going to sound really thick here. adding a honeywell t6360b to a bosch greenstar 27cdi combi boiler using 3 core for the central heating only which i've done a few times. now they are wanting to add a seperate programmer and was thinking of using a honeywell st9400c. looked at the wiring diagrams and just can't figure it out.any pointers would be greatly received. do i wire the programmer from the stat or vice versa. the boiler has only one wiring point for either a stat or programmer. and looking at the programmer theres no place for a stat to wire in. i don't do much with central heating and its proberbly really simple but i've gone completely blank.
thanks to all Daz...

 

[topquark]

Wire the programmer from the boiler (ST10 Ls Ns E). The CH from the programmer then goes to the stat and the S/L from the stat back to Lr on ST10 in the boiler. As it's a combi you only really need a single channel programmer though.


If you find it easier, put a wiring centre in! I'd run cores for CH, HW and HW off from the progammer to the wiring centre. If using the wiring centre then you'd use:

FCU (3A) to:
1 2 3 = L N E supply
1 2 -> programmer backplate
CH on backplate -> 4
HW from backplate -> 6 (won't be used)
HW off from backplate -> 7 (won't be used)
Stat N from 2, L from 4, S/L from stat back to 5
link from 5 -> 10
boiler ST10 Lr from 10
no connections for valves.
pump is built in so no connections for that.