S PLAN WIRING - fault with diagram??

[londonboy123]

just a quick point-after looking at the y plan and s plan wiring diagrams-i know HOW the systems work/link together BUT on the S PLAN the power to the cyl stat from the programmer should surely go to C and not 1!?? otherwise it doesn't make sense?? is it a fault with the diagram?

 

[nickso]

as long as the switch breaks on temperature rise it makes no difference what the markings are.

 

[D_Hailsham]

just a quick point-after looking at the y plan and s plan wiring diagrams-i know HOW the systems work/link together BUT on the S PLAN the power to the cyl stat from the programmer should surely go to C and not 1!?? otherwise it doesn't make sense?? is it a fault with the diagram?

The connections are important on a Y-plan as all three connections on the thermostat are in use; but, when you are only using two, it does not matter which way round they are.

Honeywell (assuming those are the diagrams you mean) must have used different people to do the drawings.

 

[londonboy123]

ok i get it. it just would make more sense for the diagram to make C and 1 make and break as the connection from the programmer to h/w on doesn't link up with anything and it doesn't make sense to look at!!!!!

 

[D_Hailsham]

it doesn't make sense to look at!!!!!

It make perfect sense!
The wire from Programmer HW on connects to Terminal 6, which then connects to terminal 1 of the thermostat. Terminal C of the thermostat connects to terminal 8, which also has the brown wire from the valve.
When the HW cylinder is below temperature the HW Stat will be closed so that there will be 230v on the brown (valve motor live) wire. The valve will then open, this closes the switch in the valve, connecting the grey wire to the orange and the boiler will run.
Turning the HW stat round, so that 1 connects to 8 and C connects to 6, make no difference to the way it works and is purely a diagrammatic change.

 

[londonboy123]

yep i get you. i just thought if c and 1 (with c on the lft in the diagram) made and broke connection it would look easier and more clear! but i get it!! it's also weird how 2 x 2 port vale had a permanent live each while the 3 port mid has no permanent live!!!