Why Is My Furnace Blowing Cold Air?

Is Your Furnace Blowing Cold Air?

The winter months bring harsh outdoor temperatures, and a warm house can provide a comfortable respite from Mother Nature’s wrath. When it’s time to turn on your home’s heating system, you expect to feel the warmth coming from the air vents. If you aren’t reaching the desired temperature in your home, the solution could be as simple as checking for drafts or as complex as a complete furnace replacement. Here’s a look at four reasons why your climate control system is blowing cold air instead of producing heat.

​1. Your Filter Is Dirty

One of the most important pieces of your entire furnace installation is the filter that cleans the air as it passes through the intake vent. Filters can only function until they’re clogged with dirt, dust and debris. Once the air’s path towards the heat exchanger is blocked, the unit will overheat, which could put a crack in the system. If your furnace’s internal temperature reaches dangerous levels, the unit will shut down to prevent this from happening, which could be why you’re experiencing cold air. Make sure you change your filter on a quarterly basis and do it sooner if you have pets or you’re doing renovation work that creates a lot of dust.

2. Your Thermostat Is on the Wrong Setting

If you’ve recently experienced hot air from your furnace, the problem could be as simple as a thermostat that’s set to the wrong mode. Smart thermostats have an automatic function that keeps your home within an acceptable range of comfortable temperatures by heating and cooling based on the building’s conditions. This is different than the fan’s “on” setting, which blows air without passing it over the heating or cooling exchange. If you’re getting cold out of your vents, make sure someone didn’t make changes to your thermostat’s settings.

3. The Condensate Line Is Clogged

High-efficiency HVAC systems are great at reaching comfortable temperatures without driving your power bill through the roof, but they do have the side effect of producing significant condensation. The condensed liquid runs through a PVC pipe and drains away. If this drain clogs, water will eventually back up to the furnace, which triggers an automatic shutdown.

4. An Extinguished Pilot Light

​While newer furnaces use an electric ignition to burn natural gas, older models employ a standing pilot light that’s always burning. If this small flame goes out, your furnace won’t be able to heat your home’s air. If you suspect this is the problem, follow the manufacturer’s instructions to reignite the pilot light or have a professional technician do it for you.

Stay Warm This Winter

These are just four reasons why your furnace may be blowing cold air, but don’t hesitate to contact an experienced HVAC contractor if you suspect a larger problem with the system. At Next Level Heating and Air Conditioning, we work with homeowners all over Sonoma and Marin Counties, and we’re ready to turn your home into a comfortable respite from the elements. For more information about our services or to request a free estimate, contact us online or give us a call at 707-228-9921.