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What Do I Do if My Furnace Blows Cold Air?

February 28, 2022

The last thing you want to deal with is a furnace blowing cold air in the middle of a Pittsburgh winter. With all the snow, ice, and freezing temperatures, you rely on your furnace to keep your home warm and cozy.

If you experience cold air blowing through your furnace, there are several possible causes for this issue. At Jacob Heating & Cooling, we have put together a list of the most common causes for this issue and how you can resolve them.

Faulty Thermostat

Your thermostat plays a major role in furnace operation by communicating the temperature needs of your home to the furnace. If your thermostat isn’t functioning correctly, it could cause the furnace to blow cold air.

If your thermostat is the culprit, it will need to be replaced to ensure that the cold air issues are stopped. Our experienced HVAC technicians can replace your thermostat and even upgrade it to a programmable or smart thermostat for an even more comfortable indoor experience.

Wrong Fan Setting

If your thermostat is working, be sure to check the fan setting. The blower fan on a furnace runs continuously, even if the system is not working to heat the home.

When the fan is blowing cold air outside of the heating cycle, it could be because the settings are incorrect. Check your fan setting and make sure that it is set to AUTO. It should not be set to ON; this can cause cold air to blow through the vents in between heating cycles.

Electronic Control Panel Issues

In some cases, the cold air blowing through your system could be caused by an issue with the electrical panel your furnace is equipped with. In some cases, you can resolve electrical issues by resetting the system. To reset the electrical system:

Shut off the power to the furnace using the ON/OFF switch. Give it a few minutes, and then turn the switch back to ON. If this reset doesn’t resolve the issue, contact a furnace repair professional.

Dirty Air Filter Issues

When your air filter is full of dirt and debris, it can impede the movement of air through the furnace. A dirty filter can raise the temperature inside your furnace, which can cause the limit switch to shut heating cycles down when the furnace becomes too hot.

To replace the filter, you need to find the filter compartment and remove the access door if there is one. You will then need to slide out the old filter and dispose of it.

Insert the new filter into the filter compartment and make sure to follow the directional markings that are noted on the filter frame. This will ensure the filter is placed in the proper position. Once the filter is positioned, place the access door back on.

Leaking Air Ducts

If there is a leak in your air ducts, it can cause your furnace to blow cold air. This is because the heat energy escapes through the leaky areas, causing the air to cool by the time it reaches the heated areas of your home.

Our experienced HVAC technicians can pinpoint and repair leaks to help increase the efficiency of your furnace.

The Pilot Light is Out

The pilot light ensures that fuel combustion takes place. When the pilot light is out, it will cause cold air to blow. To resolve this issue, you will need to relight the pilot light by:

  • Shut off the power to the furnace.
  • Turn the reset switch to the pilot light assembly to OFF.
  • Allow the escaped gas to clear. This will take about 10 to 15 minutes.
  • Turn the reset switch to Pilot and use a lighter or match at the pilot end to light it.
  • After lighting the pilot, you can turn the switch to ON.

Your furnace should now blow hot air.

Furnace Repair in Pittsburgh

At Jacob Heating & Cooling, we provide furnace repair to the Pittsburgh area using highly-trained technicians and high-quality replacement parts. We also offer 24/7 emergency service to keep you warm this winter in case you lose heat. Contact us today to learn more!

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