Image: a couple on a couch bundled up because their heating isn't working, cover image for Why is My Furnace Not Producing Any Heat?

It can be annoying if your furnace isn’t producing any heat. Especially when you’re looking forward to coming home to a warm house. Luckily, there are a few simple checks you can do to try to figure out the cause of the problem. If you’re asking yourself why is my furnace not producing any heat, here are some simple furnace maintenance tips that should get you feeling cozy again.

Problems with the Thermostat

Your thermostat has several things that can go wrong with it. So, it’s a great place to start your checks.

The Fan is Set to On

Your furnace will run automatically when it gets too cold in your house and shut off when it gets warm enough. The only problem is that if you leave the fan on all the time, it’ll reach the required temperature and switch to cold air. Turning your fan to an auto setting prevents this from happening.

Image: a man adjusting a thermostat.

Thermostat Being Adjusted

If you have a family member who keeps changing the thermostat setting, it can be frustrating and cause unnecessary tension in your home.

Image: a male hand adjusting a thermostat on a wall.

The best way to prevent this problem is to ensure everyone knows how to use the thermostat properly.

The Battery is Low

When the thermostat battery runs low, it will lose its memory of the schedule and your programmed settings.

A Clogged or Dirty Air Filter

If your furnace is blowing cold air, you may have a dirty or clogged air filter. When the air passes through a dirty filter, it becomes less effective at heating the home.

Image: a clean and dirty air filter side by side.

Make sure the filter is clean and free from any debris, such as pet hair. If necessary, replace it with a new one or book in a furnace tune-up.

High Limit Switch Failed

The high limit switch is a safety device that shuts off or interrupts power to the furnace if it overheats. If you think your high limit switch has failed, you need to call a professional immediately for furnace maintenance because an overheated motor can cause damage to your system.

Clog in the Condensate Drain Line

The most common reason for a furnace not to work is clogs in the condensate drain line. This line runs from your furnace to the outdoors through your basement or crawlspace. It drains water that collects inside the furnace during operation and prevents it from overflowing. If this line becomes blocked or clogged, then water won’t be able to drain properly and can damage your heating system.

A Problem with the Fuel Source

If your furnace stops working, you should always check the fuel source first. It’s possible that something has happened to the gas, oil, or electrical supply, and the problem is not with your furnace itself.

Leaking Ducts

If you’re wondering why the air in your home feels so cold, it could be because of leaky ducts. Leaky ducts are often caused by holes or cracks in the metal pipes that carry air from your furnace to different rooms in your home. These leaks can allow cold air to escape into other areas of your house, causing the temperature in those rooms to drop.

Image: metal tubing used for ductwork.

Pilot Light Isn’t On

If the pilot light goes out, it is usually due to one of two reasons:

  1. There is not enough gas pressure in the tank. This can happen if there is dirt or sediment in the tank, preventing the gas from flowing freely through the burner. A professional should be called to clean your system and relight the pilot light.
  2. The thermocouple (a safety device attached to the gas valve that shuts off the gas flow if it senses low temperatures inside the burner chamber) has failed. Call a professional to install a new one.

Burner Issues

If there’s any kind of clog in your fuel line, it will prevent proper operation of the burner. This could be as simple as a buildup of dirt and grime. The fan will still work, but because the burner isn’t working, the air going into your home will be cold.

Flame Sensor Issues

The flame sensor is located near the burners and monitors fuel burning. If it detects that the flames are not reaching their full potential, it will shut off the gas supply to prevent overheating.

The flame sensor can become dirty or worn over time. When this happens, your furnace may be more likely to trigger its flame sensor and shut down unexpectedly – not what you need!

Furnace Not Producing Any Heat? Always Call a Professional.

Furnace maintenance is crucial for your safety. When you turn on your furnace, you can’t be sure that it will work properly until it’s checked out by a professional. They’re trained to spot any issues before they become serious problems.

Image: a person putting a new air filter into a furnace.

Keep your home cozy this winter by booking a furnace tune-up with the experts. Contact ASI today and say goodbye to winter shivers and shakes.