First check that power is on, the breaker is not tripped, change filter (make sure it is not dirty— change 1x/ two months). Check to see if your pilot light is still lit. A simple test is to make your furnace room is as dark as possible. Then, you can look through the front of the furnace, and if you see a slight glow then chances are your pilot light is lit. Your furnace may have instructions for how to re-start or even diagnose your furnace. Please make sure to follow instructions closely. Once you have followed these steps and you furnace still doesn’t come on, please give us a call at 800-470-4812.