Upgrade to Y plan with room stat, cables required?

Can't comment on this - no exerience - but I imagine its alright. I'm using a CM67 (non RF) room stat which works ok. The latest RF stuff works at a different frequency from the earlier version, dedicated to intermittent operations - so hopefully won't interfere with anything else.

There's no point in having a wireless cylinder stat if all your wires congregate in the airing cupboard.

The basic Y-Plan wiring is shown in

The diagram assumes that the whole system - including the boiler - is fed via the wiring centre from a dedicated FCU. If it's more convenient to power the boiler from an FCU - and then bring the mains connections up to the wiring centre from the boiler rather than down to the boiler from the wiring centre, it will work perfectly happily. To answer your specific question, the whole system must be powered from the *same* supply rather than separate supplies - so that the whole lot can be isolated by a single switch throw. [I rewired my system to be powered from the boiler end via a 13A plug to make it easier to connect to a generator in the event of a power cut]

The wires you need between wiring centre and boiler will be:

• permanent line
• neutral
• earth
• switched live
• pump feed

So you can do everything with one 5-core cable.

Presumably the existing programmer and the switching unit for the RF room stat will both be in or very near to the airing cupboard - so connecting those to the wiring centre will be easy. You can probably continue to use the existing timer as long as it:

• provides independent CH and HW control (you may have to remove a link to achieve this)
• has a HW off connection (note that the cyl stat also needs to be a change-over type with 3 connections)

- and as long as you don't want any fancy timing programmes for the HW

So you set the existing timer for when you want HW on, and set HW to timed. You then set CH to constant - and use the programmable feature of the RF room stat to do the *actual* timing.

HTH.

Many thanks set square for the excellent advice. I will be using m supply from my boiler upto my wiring center as advised

once again Thanks

Da

-- dbroms