I installed the Honeywell yesterday and it didn't come on last night. I believe the problem may be that the new unit needs an 'L' lead which is called the 'System Monitor' and the Comfortmaker didn't call for one. Also, I see that my old 'Stage 1 heating relay' lead needs to be on the 'Auxillary heat relay' terminal. So this could be the problem also. I have both a black and a blue wire left that weren't attached in the old thermostat. Which of these do I use for the 'System Monitor'? I'll switch over the one lead when I shut down the heat pump to hook up the black or blue lead.