Whether your furnace is conventional or high-efficiency, proper maintenance can give you years of problem-free comfortable heating. However, as with all complex machines, things occasionally go wrong. If you're handy, and you feel comfortable working on your furnace, you can solve many minor problems yourself. However, if you feel over your head, you probably are. Find a heating contractor, and pay them a reasonable fee to solve your problem. You should also remember to have a qualified service technician perform an annual inspection and maintenance on your furnace.
The most common furnace problems are related to:
- Thermostat malfunction
- Tripped circuit breaker
- Blown fuse
- Pilot light gone out
- Furnace not generating heat
- Temperature swings
- Blower problems
One problem you should not try to solve by yourself: if you have a gas furnace and you smell gas, leave the house immediately. People die every year when leaking gas lines explode. Call your utility company from a neighbor's house.
Switches, Fuses, And Pilot Lights
There are times when your furnace may not appear to be providing any heat. Check that the power switch is on. If it is, check the master switch and circuit breaker or fuse. There's a possibility that the electrical system may have overloaded. If there is no circuit breaker trip or a blown fuse, the problem may be with a faulty thermostat. If the pilot light does not light or remain lit, check the thermocouple to see if it is positioned properly in the pilot flame.
Not Enough Heat
If your furnace is not heating sufficiently, check to see if the thermostat is set properly and if anything is blocking the warm airflow. Wait for a few minutes after raising the temperature 5 degrees. Are the room's heating registers open? Check the furnace filter to see if it needs cleaning. If these tips don't work, you may want to call in a furnace repair technician to attend to your furnace: the blower may be faulty or the system may not be properly set.
Faulty Thermostat And Filters
In combustion furnaces, a faulty thermostat can make the furnace cycle go on and off frequently. If you have an electric furnace, you may have an overheating problem due to clogged filters or a blower that isn't working properly. The filter might need to be cleaned or replaced -- and if that does not work, you will need a furnace repair technician. If the room temperature seems to go up and down often, you may need to adjust the heat anticipator.
Continuously Running Blower
A wall-mounted thermostat or the limit switch located on the furnace below the plenum can cause this a blower to run continuously. The plenum is the box that distributes heated hair to the ducts. If the air here gets too hot, the limit switch is set to shut off the furnace. Check to see if the fan switch in the thermostat is on. If it is on, turn it off or to auto. If it is already set to off or auto, call a technician to adjust the limit switch.
Most furnaces will provide dependable service for decades, if you provide them with annual maintenance, and you solve problems as they arise.