Does anyone know a thermostat (3 stage heating/2 stage cooling) where you can set the temp differential between 1st, 2nd and 3rd stage. Before I start digging through spec sheets, I thought I ask here. The Honeywell 8321 does not have that function.Thanks

Hey Jens - The Climatemaster ATP32U03 and 04. I believe you can also use the WF model of this stat also.

You need the change the default temperature algorithm from P&I to Differential in the installer settings and than update the values in the normal settings menu.

 

Ecobee does as well and has other internet features for your customer

The newer (second) version of the Honeywell Prestige has the following settings.

Separate 2nd stage differential settings for Cooling and Heating: 1.0°F to 3.5°F in 0.5°F increments.
Backup Electric Heat settings: 2.0°F to 15.0°F in 0.5°F increments.
Backup Heat Upstage Timer:
30, 45, 60, 75, 90 minutes, 2 to 6 hours in 1 hour increments, 6 to 16 hours in 2 hour increments.
Aux Heat Lockout feature (with the wireless outdoor temperature sensor.)

The thermostat also has some features I have not used such as Radiant Geothermal settings (we don't have radiant), and electricity Time of Use settings (rates and times not currently favorable.)

One of our original two Prestige thermostats had a wireless communication issue with the wireless remote thermostat and was recently replaced under warranty with the newer Prestige version. Our second (original) Prestige has an identical setup (with a remote thermostat) with no issues and was installed in early 2009.

Another option is Braeburn 5300 or 6300 touchscreen. Installer programming is a bit clunky but works well with adjustable differentials between stages.

http://www.braeburnonline.com/products/thermostat/5300