I have Lenox system with Honeywell Programmable thermostat. My Ac and furnace work fine. Only problem with furnace is if I feel cold in the house and if I raise temperature few degrees on the thermostat, I can hear my furnace starting. After about 5 seconds, it will turn off. After about 3-4 minutes it will restart and work fine. It happens only first time when I manually raise temperature. After that it will work fine with the new setting until I lower it or goes to programmable setting. If I do not touch the thermostat, it will work perfectly fine with whatever settings I have on the thermostat.