Reasons Behind Heater Blowing Cold Air

Heating sources mainly consist of natural gas and electric systems, though a tiny percentage use propane tanks, furnaces, and geothermal heating systems. The reason your heating system is blowing cold air will depend on the kind of heating system you own. For more information about repairs for your heater, contact Complete Home Specialist, LLC, serving in Allentown, PA and the surrounding areas

Before contacting us for heating repair go through the potential causes below to determine if the issue requires a quick fix that you can tackle yourself. 

Why Does your Heater Blow Cold Air?

  • Your Thermostat is Set Incorrectly

If you sense the furnace’s air running through the vents of the air, but it’s not cool, then perhaps you set it for summer and didn’t change it for winter. It’s also possible that your thermostat isn’t functioning correctly. If you require assistance or heating service, get in touch with Complete Home Specialist, LLC, providing heating service in Allentown, PA.

  • The Furnace Filter is Dirty

A clogged air filter could restrict your furnace’s airflow, cause it to overheat, and then shut off. As it is vital to maintain your system, be sure that you clean the air filter every 90 days.

  • Your Furnace has Overheated

If your furnace is overheated, it has a safety feature that will shut it off. Therefore, not only will the furnace blow cold air, but it will also shut down. There are several possibilities that your furnace may be running hot (besides an obstruction in your filter):

  1. Dirt buildup
  2. Mechanical failure
  3. Age
  • The Condensate Line is Clogged

Condensate lines in high-efficiency furnaces drain out the water from their furnace. A blockage within the condensate lines will stop your furnace from burning. In the absence of ignition, you will only have cold air entering your vents. It could also be due to an issue with the condensate drain line, but an HVAC technician will be able to inform you what the issue is.

  • The Pilot Light keeps Going Out

Most new furnaces have an electric pilot light that will turn on when required. Older models will have a pilot light that will be on continuously due to a gas supply. If that’s the case, the furnace is programmed to shut down in case of an issue in the gas supply. It is not easy to solve this problem; contact one of our experts for heating repairs in Allentown, PA.

  • The Air Ducts are Leaking

If you notice gaps or leaks in your air ducts, the heat escapes before it can get into your vents. It may happen due to the age of the system. Leaking ducts cause more damage than you’d imagine, and duct sealing could be the solution, whether using tape or new pieces depending on the level of damage. A professional should conduct an inspection to identify the areas of concern.


You can solve most HVAC problems or issues with just a few tests or by calling an expert if you’re uneasy about doing everything yourself. For more information about repairs for your heater, contact Complete Home Specialist, LLC. Reach us at 610-790-3835 or visit our website to learn more about our heating services in Allentown, PA.