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Why Is My Heater Blowing Cold Air?

February 16, 2024

Feeling cold air when you expect warmth can be frustrating. If your heater is blowing cold air, several potential reasons could be behind this issue. The specific cause might vary based on the type of heating unit you have, be it a furnace, boiler, or heat pump. However, some problems are common across various heating systems.

For most issues, consulting an HVAC professional is advisable. Here are some common reasons for heating malfunctions:

  • Thermostat issues
  • Pilot light or ignition problems
  • Malfunctioning furnace
  • Insufficient fuel
  • Heat pump issues
  • Leaky ductwork
  • When to seek professional help

While some issues might be easy to identify and resolve, others demand expert attention. In this guide, we'll delve deeper into each potential problem and discuss solutions.

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Thermostat Issues

If your thermostat is broken, you probably need a new one, but you should always try troubleshooting first. If you have a smart thermostat, it could be frozen and need a reset to start providing heat properly. When your HVAC unit doesn't get the message to turn on from the thermostat or it's stuck in cooling mode, you might notice cold air coming from the vents. Disconnecting the thermostat from electricity and plugging it back in is a good first step to see if that fixes the problem. If not, you may need a new thermostat.

Pilot Light or Ignition Problems

When your pilot light is out, the rest of your furnace might still run, but there's no heat. The blower moves air that hasn't been heated, essentially air-conditioning your home in the wintertime. Fuel-burning systems need a source of fire for combustion. Any issues with igniting a fire can leave you without heat.

Malfunctioning Furnace

Your furnace might also be broken. If you're wondering why your furnace is blowing cold air, and you've already checked your thermostat settings and pilot light, it likely means there's something wrong with the furnace. It could have a broken blower, worn belts, or dozens of other issues that may impact heating performance.

Pay attention to subtle performance differences to give your HVAC pro good information when they arrive. Is the air actually cold, or is it lukewarm? Is air blowing from the furnace or a draft coming from the vents? The more information you can provide, the easier it is for your technician to determine the source of the furnace malfunction.

Insufficient Fuel

If your furnace is running properly, but you're feeling cold air, it might mean you don't have enough fuel. Combustion systems work by burning a fuel source, so when the fuel runs out, so does the heat. However, the air still moves through the system without warmth, leaving you to shiver under an arctic blast from your vents.

Heat Pump Won't Switch to Heating Mode

Heat pumps move air from one place to another. When they're in cooling mode, they pump heat out of your home and bring in cooler air. In the winter, they pump in warmer air and remove cooler air. If the heat pump doesn't switch out of cooling mode, the air blowing from the unit will always be cold. Check the settings on the unit and call in a professional if the heating mode won't engage.

Leaky Ductwork

Another possible source of cold air from your vents is leaky ductwork. Your furnace might be working fine and pumping out plenty of hot air, but if that air leaks out of the ducts, it won't make it to each room in your home. Your furnace could be working overtime depending on where the leak is and how many leaks there are.

When to Call the Professionals

If your home doesn't warm to the set temperature, you should have your heating system checked by a professional. In many cases, the issue is easy to fix but difficult to diagnose. Having a trained HVAC technician take a look can save you hours or days of discomfort.

Need help with a malfunctioning furnace?

Call Jon Wayne today when you need furnace repairs from a NATE-certified technician. We work on all types of units, including heat pumps, and have thousands of 5-star reviews to attest to our quality service.

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