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Does an HVAC System Blowing Cold Air Indicate a Broken Heater?

The Common Symptoms of a Broken Heater

Discovering why a heater is suddenly blowing cold air instead of hot air isn’t always a straightforward process, even for the trained HVAC professional. There are a variety of problems that can be causing the issue of a broken heater blowing cold air, some of which require professional assistance and others that can be solved by the homeowner with a little problem-solving.

Knowing how to figure out exactly what is causing the issue, and if it can be fixed without hiring a professional, can save time, money, and frustration.

Broken Heater or Simple Furnace Setting Issue?

furnace settingsWhile many people jump to the conclusion that they are dealing with a broken heater when it starts to randomly blow cold air, the answer may be as simple as a wrong setting on the furnace system.

If the fan setting on the furnace’s thermostat is set to “on,” it will blow air 24 hours a day, 7 days a week. While this can be fine when the furnace is producing hot aid, when it isn’t, the furnace will continue to push cold air out instead of waiting for the air to heat back up.

For a constant source of hot air in the winter, make sure to set the thermostat to “auto” instead of “on.” That assures that the furnace will only be blowing hot air when needed, and not simply blowing air out regardless of its temperature.

Is It a Broken Heater or Just Overheated?

Knowing the signs of an overheating furnace can save the homeowner time and money, as well as possibly being able to have an HVAC technician perform a repair instead of having to replace an entire broken heater.

Signs that a furnace may be overheating include a “hot” or “burning” smell, a heater that is no longer blowing hot air (even after fixing the thermostat setting), and unusual noises like a loud hum or rattle.

overheated heater

Even with immediate servicing, a furnace that continues to overheat may still need to be replaced. Broken heaters like this become a significant fire hazard and replacing it is often a safer and ultimately more cost-efficient option.

It Isn’t a Broken Heater - It’s Just a Dirty Air Filter!

dirty filterOne of the most simple ways to fix a broken heater is also the most overlooked. Broken heaters that are blowing cold air are often not “broken” at all, they just need to have their dirty air filter changed!

Dust and dirt that builds up on the air filter can block the flow of warm air from the furnace, which can lead to cold air as well as overheating. Because of this many people are also interested in heat recovery ventilators, which maximize air quality while using air from outdoors. 

If a homeowner is not familiar with the process of changing the air filter, they should contact a professional who can perform the regular maintenance as well as showing them how to change their air filters and advise them on how often it should be done, this also helps air quality inside your home.

Cold air doesn’t have to be the result of a broken heater, and it can be fixed for as little as just a few dollars by a homeowner who knows what to look for.

Trust Lambert Plumbing & Heating, LTD

Lambert Plumbing & Heating, LTD has been serving the Metro Vancouver community 24 hours a day, 7 days a week since 1977. In addition to providing quality, knowledgeable plumbing, and heating services, they also help support local organizations like the Children’s Miracle Network.