- Check Electrical Panel
Check your fuse box for any tripped circuit breakers, especially since this could indicate a bigger problem with your electrical system.
- Check Furnace Power
Look for the power switch mounted on the side of the furnace. It may also include a liftable metal housing containing a fuse. If the fuse is blackened and burnt, then it will need to be replaced. However, remember that a blown fuse may also indicate a bigger system problem, so the system should be inspected by a licensed technician.
- Check blocking of the Fresh Air Intake and Exhaust Pipe
If your furnace have their fresh air intakes and exhausts through the side of the home, check for the blockage. Sometimes leaves, insects, and moisture affect heating systems. Check if the intake and exhaust pipes are not covered by snow.
- Check your Thermostat Settings
Make sure your thermostat is communicating with your furnace and has been set to “heat”. Furnace will not run if the set temperature and room temperature is same. While that sounds obvious, it’s a small detail that is easily forgotten by a worried homeowner.
If you are using a Smart thermostat like NEST, Ecobee or any other, you should check the manufacturers guidelines or contact their technical support. Most of the time there is some software update or a technical issue due to which your smart thermostat is not communicating with the Furnace.
- Check Thermostat Batteries
Many programmable thermostats feature a flashing “low battery” icon on their control screen. If you see a “low battery” warning, promptly replace the batteries with new ones.
- Check your Furnace Filter
If your furnace is firing up but it’s not blowing as hard as it normally does, then it might mean that the air filter needs to be changed. Furnace Air filters trap dust, hair, and other particles in the air and, over time, the filter gets so full of debris that it can restrict air flowing through your furnace system. On most residential heating systems, air filters should be changed every 3 months.
- Check the Access Door
As a safety measure, the furnace turns off whenever you open the access door. If it is still open, even slightly, the safety switch inside will prevent operation. Fully close the door and ensure the latch is in place.
- Flush out Drain Lines
High-efficiency furnaces can drain off several gallons of water a day in heating season. If the drain lines become restricted by sediment or mold growth, the furnace will shut down. If the drain hose looks dirty, remove the hose, fill it with a mixture of bleach and water (25 percent bleach), then flush it after several minutes.
- LED Status code
Record the LED status code BEFORE removing the blower access door or turning off 115-v power to the furnace. See the information booklet inside the main furnace door for a service code legend.
- Blocked return air supply
Check for blocked return-air or supply-air grilles. be sure they are open and unobstructed.
- Manual shut-off Valve
Is the manual shut-off valve in the gas supply pipe leading to the furnace open.