I have the Goodman Janitrol Dependable 92 gas furnace. My question has to do with the operation of the fan. I have a honeywell rth7500 thermostat that is not using the dual heating and A/C setting. On cold days, we use a kerosene heater to supplement the house's heat. When the house temperature rises 7 or 8 degrees above the thermostat calling temperature, the fan starts to cycle on and off. The thermostat setting for the fan is set to auto. The fan will kick of for ~15 minutes, go off for ~30 minutes and kick back on. This does not happen when the actual house temperature is close to the thermostat temp setting. The honeywell tstat is a replacement for a ritetemp that was doing the same thing. I replaced the ritetemp thinking that may have been the problem - but it wasn't. I realize that this is not a big problem since my heating and cooling is not affected, but am just curious as to why this may be happening.