Thermostat/Programmable Thermostat

6 Oct 2008
Reaction score
United Kingdom
Hi All,

We have an S-Plan system driven by a Potterton EP2001. All our radiators have TRVs and we do not have a thermostat. It looks like we do not have an auto bypass valve, but a 15mm gate valve between the pump & the HW return.

I want to fit an RF thermostat & also upgrade the programmer to one where we can set the HW & CH to different times. I'm looking at the Honeywell ST9400C. However I've seen a few people on this site suggest a programmable thermostat.

Is there much advantage to using a prog. thermostat? I'd have to set the Potterton to permanently on (or get a separate timeswitch for the HW).
Also cost-wise would the cost of an ST9400C and a decent digital RF thermostat be equivalent to a good Honeywell CM727 or CM927?

Any advice gratefully received.
Sponsored Links

DIYnot Local

Staff member

If you need to find a tradesperson to get your job done, please try our local search below, or if you are doing it yourself you can find suppliers local to you.

Select the supplier or trade you require, enter your location to begin your search.

Are you a trade or supplier? You can create your listing free at DIYnot Local