Replacement Programmer or Addition of Room Stat?

[mrscalex]

We're just about to have a new boiler fitted. With the ceilings down for other work I have the opportunity to re-run cables and relocate the Central Heating/Hot Water timeswitch currently in the upstairs airing cupboard to downstairs (ie into a more convenient place), replacing it in the process with a modern programmer.

However, since the regs require me to add a room stat now anyway... I'm wondering whether gaining superior control of the central heating is better achieved (and more simply implemented) with the room stat and leaving the timeswitch as is (old mechanical Switchmaster 400 but it works fine).

As I understand it the timeswitch can still control timing of the hot water. But the room stat can exercise full control of the central heating independently of the hot water.

In case it helps I have a Y-Plan system with a 3-port Honeywell valve.

I'm happy to make an investment in a decent room stat. Another thread suggested the Honeywell CM67 was a good one to go for.

Thanks for any help confirming or otherwise any of the above.

Regards,

Robert

 

[ChrisR]

You got it. Leave the CH on const on the switchmaster, and use a prog stat.

I think the CM67 is about the best. Randalls TP5000 is OK but only 5/2 day not 7 independent. Drayton's Digistat 3 is a dog to program.

The Optimum Start version is clever and worth the extra, though it can appear to do some odd things!

 

[mrscalex]

Great - thanks for the very fast reply!

However the Switchmaster 400 just has a water only or water+heating toggle switch. So how do I achieve timed water and constant heating? Presumably not from the controls and only by hard-wiring?

Thanks,

Robert

 

[ArtfulBodger]

You got it. Leave the CH on const on the switchmaster, and use a prog stat.

I think the CM67 is about the best. Randalls TP5000 is OK but only 5/2 day not 7 independent. Drayton's Digistat 3 is a dog to program.

The Optimum Start version is clever and worth the extra, though it can appear to do some odd things!

I've given up fitting the CM67, it's just toooo clever by half. "I'm off on holiday" button, "I'm having a party" button - just too many buttons. Optimum start is guaranteed to confuse just about everyone, especially me.

 

[bathjobby]

I fitted one of these http://www.heatmisershop.co.uk/Heatmiser_DT__High_Power-p-16134.html 2 years ago, brilliant.
With regards to your programmer, no idea, but haven't I just read the same question in another topic or yours !

 

[mrscalex]

Thanks.

Yes, you did see a similar question! I found out a bit more myself in the meantime and wanted to verify it. Should have kept it in the same thread on reflection.

Regards,

Robert

 

[nstreet]

I installed the cm67 last year, brilliant stat and easy to install. I also had the switcmaster sm400 but changed it for a Honeywell ST799.