Which Centralling heating plan?

[yrob]

Hi,

I've recently had some problems installing a new timer switch but after some digging have come to the conclusion that I'm not sure which Central Heating plan I have, i.e. Y, C, W etc. I have the following:-

Honeywell ST6400 timer
Honeywell v4043 zone valve
Room Stat
Cylinder stat
Ravenheat CSI Primary boiler - requires pump overrun
Pump is next to the boiler and wired direct
Store hot water in loft - indirect I believe

I would be grateful if anyone could state which plan I have so I can then source the correct wiring diagram for the Control center. Many thanks in advance.

 

[Mike Jackson]

If the pump is wired direct from the boiler then it must be fully pumped which would point to an S plan but you need two zone valves for that. There must be another zone valve unless it is not wired to a plan.

Mike

 

[yrob]

Thanks Mike. Yeh getting a bit confused. There is def only one Zone valve and the wiring center was orignally wired with that but no pump overrun to the boiler. Any further thoughts??

 

[sonray ltd]

wheres the zone valve fitted ?

 

[yrob]

The valve is under the floor on the upstairs. The boiler and pump are below this in the garage.