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Why Is My Furnace Blowing Cold Air?

One of the more common furnace issues, especially among homeowners whose heating systems are old, is a furnace blowing cold air. You rely on your furnace blowing hot air, so when your furnace is blowing cold air, it’s not only confusing but uncomfortable, especially during chilly winter storms. The following problems may be the reason for your furnace blowing cold air:

Thermostat Troubles

Over many years of furnace repair in Toms River, NJ, we’ve found that the first thing to do when a furnace acts up is to go to its “brain” by checking the thermostat. Make sure your thermostat is set to “auto” rather than “on” because “on” means the thermostat’s fans are running all the time, which can cause problems and cost you big on your heating bills. One other thing that sometimes slips people’s minds is to switch the thermostat from “cool” to “heat” so that the furnace is actually heating your home. Our HVAC technicians have been around the block before — your furnace blowing cold air might actually be your air conditioning, and you didn’t notice!

Dirty Filter

If your furnace is blowing cold air even after adjusting the thermostat, the next thing to check for is a dirty air filter. Similar to your vacuum cleaner, which can’t suction up dirt effectively when it’s already full, a furnace air filter that’s filled with dirt and dust will have a hard time heating your home. While we can sometimes help customers find their model of furnace to replace the filter themselves, we recommend calling a furnace repair professional if you don’t know what you’re doing — or scheduling regular furnace tune-ups so that you can have your filter changed out every 6 months.

Leaking Air Ducts

While your air ducts are designed to perform as “pipes” for hot air to travel through, sometimes there are gaps, cracks, or holes in air ducts. If there are issues with leaks in your air ducts, it might be the culprit for a furnace blowing cold air.

System Is Overheating

It may sound like a strange problem for something designed to heat the air, but is your furnace blowing cold air because the furnace itself is overheating? If your furnace reaches a temperature that the system detects is too hot, the unit’s built-in limit switch ensures that the gas valve is closed and gas supply is cut off, protecting you from dangerous carbon monoxide exposure. However, this can cause a reaction where your furnace is blowing cold air. If you think overheating could be causing the issue with your furnace blowing cold air, get in touch with HVAC experts ASAP. 

Wiring Problem

A wiring problem might also be why your furnace is blowing cold air. A furnace blowing cold air due to a wiring system problem will have trouble starting up and turning off, you’ll smell an acidic or “burning” odor near or around the unit, or if it manages to start up, it will work poorly. You might also notice a pilot light that keeps going out or flame sensor problems. You don’t want to risk a fire, electrical shock, or huge energy bills, so a problem with furnace wiring should be diagnosed and dealt with by HVAC professionals as well.

Clogged Condensate Line

Not all furnaces have condensate drain lines, but if yours does, a clogged condensate line could be the reason for a furnace blowing cold air. The condensate line is important to the heating cycle as it carries water away from the furnace and helps it ignite reliably. However, if this line is clogged, you might not even be able to start your furnace up, or you’ll notice your furnace blowing cold air.

Faulty Furnace? Contact Care Temp, LLC!

Is your furnace blowing cold air? Need complete system replacement or want to change to a greener alternative? No matter what kind of HVAC services you need, Care Temp, LLC has your back. Let us help you stay comfy this year and for many years to come. Contact us today for a FREE estimate on our furnace services!

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