In a perfect world, your furnace would always heat your home the moment you need it.
But when temperatures drop and your furnace stops cooperating, you need to know how to troubleshoot quickly. Here are the top five most common problems homeowners experience with residential furnaces and what you can do about them.
Not Producing Heat
This is the most alarming furnace issue and can lead to freezing indoor temperatures if not addressed quickly. Sometimes the fix is simple:
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Check that the thermostat is set correctly
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Make sure the pilot light is lit (for older furnace models)
If neither resolves the issue, the problem may be more serious and requires professional furnace repair. After checking these basics, contact Comfy Air Cooling & Heating for assistance.
Noises Coming From the Furnace
If you’re hearing sounds beyond the typical low hum of your system—such as grinding, clanking, banging, or rattling—this usually signals a mechanical issue. These noises shouldn’t be ignored. A trained HVAC technician can inspect the furnace, diagnose the cause, and prevent worsening damage.
Furnace Not Turning On
Another common problem is when the furnace fails to turn on altogether. Often, this relates to the thermostat:
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It may be misreading the temperature
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Settings may need adjusting
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The thermostat may be failing and need replacement
If you can’t find an issue with the thermostat, the furnace likely requires professional attention.
Short Cycling
Short cycling occurs when the furnace turns on and off in very short increments. This often indicates restricted airflow. Try the simplest fix first:
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Check your HVAC filters and replace them if they’re dirty
If replacing the filter doesn’t solve the issue, the short cycling could signal a bigger problem with the furnace or blower motor. A professional should inspect the system.
Blower Running Constantly
If your blower never seems to shut off, start by checking your thermostat:
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Ensure the fan setting is on Auto, not On
If the fan isn’t set to run continuously, the issue may be a faulty limit switch, which requires professional repair.
Call the Professionals
If you’re experiencing any of these common furnace issues, Comfy Air Cooling & Heating is here to help.
Learn more about our heating services and how we can keep your home warm and comfortable all winter long.
