Add heating Zones to C-Plan Gravity System

[Haggistrap]

Hello,

I want to add two heating zones to my C-plan system. Right now I have a C-plan system with a zone valve and c-stat for the hot water. I want to go a stage further and zone the heating by adding two zone valves to allow independent control of the ground and upper heating areas.

Right now I have;

Drayton RF room stat
Horstmann H27xl - programmer for HW and CH
Honeywell 2 port valve on the heating circuit

The above works fine, when the programmer is "on" and the room stat signals demand the pump starts and the boiler fires.

However I want to place zone valves at the appropriate place on the heating pipework, one for the ground floor and one for the upper floor. The pipe work is such that this can be done.

I am going to add an additional programmable room stat to control the upper floor. (Drayton RF 701+3)

Question -

What will the wiring be? I can find no C-plan diagrams with heating Zone valves, only S-plan.

I have a Honeywell wiring center I was going to install at the same time as the upgrade.

Thanks fro reading and any advice given.

Terry

 

[oph]

http://www.honeywelluk.com/products/Systems/Wired-Sundial/Sundial-C-Plan/

Try the downloads section. It should give you some idea anyway

 

[mikely]

Assuming that your current system is wired as here: http://www.honeywelluk.com/Documents/All/pdf/936.pdf, I think the following would work:

For each heating zone, you could add a two port valve controlled from its room stat (as per S plan) with its switched output (orange) connected to terminal 9 in the C plan diagram. When either zone valve is operated, the pump will run and the boiler will fire via the tank zone valve.

Or covert to a fully pumped S plan; but I guess you have considered that:
http://www.honeywelluk.com/Documents/All/pdf/938.pdf