When the temperature drops the last thing you want is for your heating system to stop working, or worse, blow out cold air! Here are a few troubleshooting tips that might get your furnace back on track before you need to call a professional.

Thermostat Problems

Make sure your thermostat is set to “heat” and your fan is set to “auto” not “on.” Having your fan set at the “on” position will cause the furnace blower to constantly run, even when it isn’t heating the air. Also, if you have recently installed a new thermostat, it may be incompatible with your heating system and if you’ve had your thermostat for some time, it may need new batteries.

Overheated Unit

Does your furnace blow hot air, then cold air, and then stop blowing altogether? Your furnace may be overheating. The limit switch, a safety device on your furnace, may be turning off your furnace’s burners. In this situation the fan will keep running in an attempt to cool down the overheating furnace. The most common reason for an overheating furnace is a dirty air filter blocking airflow, causing your furnace to run to the point of overheating. This cycle is extremely damaging to your furnace’s heat exchanger, which is expensive to repair or replace—so don’t ignore it, change the air filter!

PilotLight or Ignition Problems

If you have an older furnace with a continuous pilot light, it may have blown out and need to be re-lit. You can try to relight the pilot yourself (your unit’s instructions can be found on the unit or in the user’s manual) or you can call one of our technicians for assistance. If you attempt to relight the pilot but it won’t stay lit, check that gas is flowing into the furnace (gas valve switch is in the “on” positionwhich is parallel with the gas supply pipe). If it still won’t stay lit, then there’s likely a problem with the thermocouple (the copper rod the pilot flame hits). An adjustment or replacement of this component is technical and best left to a professional. If you have a newer furnace with an electronic ignition (i.e.intermittent pilot, hot surface ignition), your system may need adjustments or part replacements performed by an HVAC repair technician.

CondensateLine Clogs

Newer model, high-efficiency furnaces have condensate drains which remove water that is created during the heating process. If these drains become clogged, the water backs up and activates a switch that prevents your burners from lighting.

Call the Professional Team at Atlanta Air Care

There are a variety of other problems that can arise in a complicated HVAC system such as duct, valve, oil filter, flame sensor, gas supply, and burner problems. These are all situations where a knowledgeable technician is your best bet for getting your heating system running correctly again. Keep your home warm and comfortable this winter—contact us today!