You've enjoyed months of cool comfort thanks to the air conditioning portion of your central HVAC system. With temperatures plunging towards freezing, now's the time to put the heating portion to work. Now would be a bad time to discover that while your air conditioning works like a champ, your furnace seems to be out of action.
The last thing you need this winter is a furnace that's out of commission. Here are a few common problems that can easily sideline your furnace, along with some tips on how to bring your furnace back from the dead.
Your furnace won't turn on if doesn't get any power. If there's a master switch for your furnace, toggle it to the "ON" position and see if your furnace works. You should also check the circuit breaker and make sure the furnace's assigned circuit isn't tripped. If your furnace works after resetting the breaker, only for the breaker to trip shortly afterward, have your HVAC technician check for any electrical issues.
A malfunctioning thermostat can also prevent your furnace from working properly. Common malfunctions include getting air conditioning when you've clearly called for heat, uneven heating and short cycling. Before you do anything else, make sure the thermostat isn't located next to an artificial heat source, a drafty area or an area that's constantly exposed to sunlight.
Check your thermostat for any signs of physical damage. If it's been a few years since you've last replaced your thermostat, it may be time for a newer replacement.
Faulty Igniter or Pilot Light
Oil and gas-fired furnaces rely on a pilot light or electronic igniter to light the burners and deliver the heat your home needs. A faulty igniter or pilot light can prevent the furnace burners from firing. Follow your furnace manufacturer's instructions for relighting the pilot light. If the pilot fails to light or quickly extinguishes itself, you may be dealing with a bad thermocouple that needs professional replacement.
To diagnose a faulty igniter, power-cycle the furnace by shutting it off for a few minutes and then turning it back on. If the igniter fails to light the burner, have your heat and AC repair technician inspect and, if necessary, replace the igniter.
Faulty Heating Element
On electric furnaces, a faulty heating element can also result in a no-heat condition. Try power-cycling the furnace to trigger the heating element. If the heating element still fails to work, have your HVAC technician replace the faulty component and conduct other checks to ensure your furnace's proper operation.