No one expects a gust of cold air when cranking up the heat. When this happens, you may be quick to think the worst. However, there are actually a few common reasons this could be happening. While you should still call a trusted heating contractor to properly diagnose and resolve your issue, here are five potential explanations for your heater blowing cold air.
- Thermostat Issues. Your first move should always be to check your thermostat. Check the temperature settings as well as batteries, if your thermostat takes them. Perhaps the most common issue is the fan setting turned to “ON” rather than “AUTO”. This setting keeps the fan constantly moving, even when the heater isn’t warming the air.
- Damaged Ductwork. If hot air is not making it from your furnace to the vents in your home, it might be a sign of damaged or leaky ductwork. Because the ducting is normally fed through attics and crawlspaces, inspecting the ducts yourself can be a dangerous job. If you have reason to suspect an issue with your ducting, be sure to call a professional.
- Clogged Air Filters. When is the last time you changed your air filter? Dirty or clogged air filters can restrict airflow into your furnace, which triggers a safety setting to shut down the burner.
- Pilot Light Gone Out. While we’re sure you’d check and relight a pilot light, it’s important to notice whether or not your pilot light consistently stays lit. If the light is always going out, it may be indicative of a problem with the thermocouple.
- Ignition Problems. If your pilot won’t light, there may be an issue with fuel reaching your gas furnace. This could be an inadequate gas supply or a faulty valve. If you have an electronic ignition, your system may need some adjustments.