Qball wrote: The only thing I want to change is the thermostat to a programable one. The round Honeywell is off a few degrees from my digital oil furnace one.
I thought you could adjust most thermostats to "calibrate" them. Check to see if there is a set screw on the round bi-metallic to balance it so the switching point matches the digital readout. The mercury switch ones ya could just mount a little off level to "calibrate" them.