Anyone know of a low differential programmable thermostat?

[RoyMacDonald]

I've been trying find a programmable theromstat with a better than 0.5 C differential.

My present ones if set to 19.5 C, rise to 20.1 C then turn off and come back on at 18.4 C This gives too long on and off periods with the temperature being too hot then too cold.

Thanks.

Roy

 

[Boilerman2]

Try a Honeywell CM927 you can set the Hysteresis to suit your application make sure you set the option for fuel type, I don't think you can buy a better controller IMHO

 

[RoyMacDonald]

Thanks.

Looking at the Honywell pdf seems to say the differential is + or - 0.5 C which is the same as the ones I have. It does not mention an ability to set it to 0.25 C Is that correct?

I should say I want to use it as a two wire on off thermostat into an EZC-12 Microcenter, and I need 5.

 

[RoyMacDonald]

After reading lots of tech information pdfs I bought a Grasslin Famoso 1000 and that has a 0.25 C switching differential but is also has an integral compensation program that keeps the differential close to 0.1 C after it starts running the heating demand. Absolutely brilliant.

My only criticism is that you need to be very careful to keep the unit square and parallel when plugging the unit into the backplate.

So no more complaints about the temperature falling too low and no wasteful over runs.