Hello
My furnace blows cold air at the beginning and at the end of each cycle, is this normal?
Also the furnace seems to start every 15 minutes regardless of whether the temp. drops or not. I was watching the thermostat last night and the temp. would not drop on the thermostat screen but the furnace would turn on.

Thanks
Jesse

When the furnace starts a cycle, the cool air in the ducts must be displaced before warm air is produced from the registers. At the end of the heating cycle, the blower runs until the furnace "cools down". If you have a digital thermostat, temperature is displayed in whole degrees but measured in fractions of degrees (usually 1/16-1/32), so response is more sensitive and temperature control more accurate vs. mechanical-type thermostats.