Turn the thermostat to heat mode and set it to 80 degrees, just for testing. You should hear the furnace turn on, and warm air should begin to blow within a few minutes. If the furnace is running fine, turn the thermostat back to its normal setting. If it’s not running properly, you can try to diagnose it as outlined in Gas Furnace Repair and Troubleshooting. Depending on what’s wrong, you may be able to fix it yourself, or you may need to call a qualified service technician.
If you have a propane or oil furnace, make sure to have your fuel storage tank topped off and ready to go.
Clear obstacles to heating vents, so air can freely flow. Many experts recommend having a service technician come in and clean the vents every year or two.
Check for carbon monoxide leaks:
This silent killer can easily be detected with either an inexpensive test badge or battery-operated alarm. Whichever way you decide, just please decide to protect your family with one of these units.
See Testing for Carbon Monoxide for more information.