Closing Air Vents Can Damage a Furnace

If you want to have a warm and cozy holiday, you must take care of your furnace. However, besides keeping up with furnace maintenance, it’s also crucial to keep up with other areas of your home that may affect your heating, such as the air vents.

A broken furnace is the last thing anyone wants during this time of year, but you’ll most likely get into this predicament if you keep closing your air vents. Some people believe that closing the air vents in unused rooms helps cut down on heating, but it causes the complete opposite!

How a Furnace Works

Furnaces have a small blower connected to small holes in the furnace’s exterior. Unused air vents are vital to this process, and they keep the cool air inside the house moving with the warm air that is being blown out by the furnace.

Closing these vents makes the heating process more expensive because the furnace works harder to keep the heat inside the house at a consistent temperature. When you close your vents, you disrupt the flow of warm air that’s being circulated throughout the rest of your home. Shutting off the air vents essentially cuts off your heater from its source of fuel!

What Happens When You Close the Air Vents

You may have heard that closing your air vents is a way to cut down on money spent on heating a room, but this is not the case. Instead, it makes your furnace work harder and, in most cases, runs it longer than it would if you just left it open!

Closing your air vents can have several adverse effects on your heating system, including:

Higher Energy Costs

When you close your air vents, your home has to work harder to keep the heat at the perfect temperature. This extra work and energy use can be costly and even lead to a higher electricity bill.

Exhaustion and Damage

This extra work can cause your furnace to wear out faster than it would have if you weren’t closing your vents. This can result in repair costs and high costs to replace the entire furnace.

Risk of Carbon Monoxide Poisoning

In general, it’s not a good idea to close the air vents in rooms that you’re not using. Instead, keep the vents open, run your heater at a consistent temperature, and keep the air flowing to your heater to keep it working as it should!

A Hot, Stuffy Home

When you close your air vents, you prevent the hot air from flowing into other rooms and outside the house. This is because the only way warm air can escape the room is through the air vents’ holes. Since the warm air is condensed and cannot move, the room where the air vents are positioned begins to heat up quickly.


Keep your air vents open to keep your home comfortable and safe during the holidays. As long as you keep your air vents open and invest in regular furnace maintenance, you have to worry about expensive furnace repair costs and other problems!

If you need furnace maintenance and repair, contact one of our heating and cooling specialists at Legacy Heating. With many decades of experience in the field, we pride ourselves on putting quality and customers first! Furnaces, Air Conditioning, Hot Water Heaters, Garage Heaters, Humidifiers, Thermostats, Filters and more! 

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