Thermostat and programmer replacement

[nstreet]

One for the plumbing guru's

I would like to replace my mechanical timer and old room stat with new ones. The old timer is playing up and the room stat is in the wrong place.

I would like to use the Honeywell CM67rf programmable room stat, because its wireless so less hassle installing and it also has the nice optimum start feature.

My question is if i use one of these how to i control the HW. Do i still need a conventional timer? If I use a conventional timer, then the optimum start may not work becuase the heating will only be triggered when the timer allows and not from the demand from the room stat. Am I correct in assuming this?

 

[oilman]

You need a timer/programmer for the DHW, but the RF stat takes over control of the heating. If you had a programmer for the heating originally, the CH would be set to constant.

 

[nstreet]

Thanks Oliman,

Didn't think of running the heat on constant.