There are a few common problems that you can troubleshoot on your own. First, simply check to be sure that your furnace has been switched to heat. A surprising number of thermostats have not been set correctly before winter starts. Next, replace the filter. This is an inexpensive fix that can prevent a lot of trouble and improve the efficiency of your system. The next important step is to check batteries and make sure that the furnace is receiving electricity. Older furnaces have pilot lights that sometimes need to be relit.
There are some safety issues that can crop up as you try to troubleshoot and perform repairs on your own. A good guide to follow when it comes to calling in a heating technician is: when you begin to feel uncomfortable, call in the professionals.What If My Air Conditioning Unit Stops Working after Thermostat Change? » « What Are the Most Common Issues That Stop My Heating System from Working Efficiently?