Strange Stat Behaviour

[TheScullster]

Hi all

Our CH system is controlled by 2 CM67 Honeywell programmable stats (upstairs/downstairs). For some reason, the downstairs one doesn't seem to be responding correctly.

It was quite chilly recently (evening) and the stat was showing 18.5c (probably nearer 15 actually). If I increase the required temperature above that shown, the heating fires up OK. But the stat does not seem to be "following/sensing" the ambient temperature correctly.

Is this a low battery feature or something more fundamental?

TIA

Phil

[cynic]

Turn off the intelligent forecasting facility - it probably knows its going to be a warm night and is saving your fuel.

[Mike Clarke]

If the battery is more than a couple of years old it might be worth trying a replacement. If you don't have a suitable one handy try swapping batteries between the upstairs and downstairs stats.

I don't think they look that far ahead. I'm not sure about the CM67's but the CM927's won't advance the start up by more than 2 hours and they certainly don't delay it.

[ARWadsworth]

Swap the programmers over to see what happens?