Replacing the Programmer with Programmable Room stat

15 May 2013
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United Kingdom

Right system is a S Plan which currently has a Horstmann ChannelPlus XL (3 Channel programmer). This is only using 1 zone for CH and 1 for DHW, thus zone 2 is unused. Each channel has a Honeywell V4043 zone valve.

I have just installed a Honeywell CM907 so that I can have different temperatures at different times of the day and different temps at the weekend. This now means that the Horstmann programmer has the CH zone set to ON all the time as the CM907 controls the switching of the Boiler and the CH zone valve. (a small wiring change in the wiring centre would mean that the CH zone could be controlled directly from the CM907 thus zone 1 CH on the Horstmann would also not be wired.

Now my question is I hate the look of the Horstmann programmer and was considering replacing this with a Honeywell ST9100C 7 day programmer just to control the DHW via the L641 cylinder stat.

Apart from some simply changes to the wiring in the wiring centre is there any reason why you would not run a central heating system with two separate programmers controlling CH and DHW.

Oh forgot to mention that the Boiler is an Ideal Logic + Plus 30kw System Boiler not that, that should make any difference.


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