an HVAC technician inspecting a ductless unit

When a previously working HVAC unit starts to blow cold air, many homeowners begin to wonder if they are dealing with a broken heater. Some issues that cause this specific problem may require professional assistance from a trained HVAC technician, while others can be solved easily by the homeowner with just a little troubleshooting.

With the temperatures starting to drop here in Utah, it is important to deal with a potentially broken heater before Winter starts.

Always Check A Broken Heater’s Furnace Settings

clip art of hand holding gears

When a heater starts to blow cold air, it may just be a result of an inappropriate furnace setting instead of an entirely broken heater. Before calling in an HVAC professional, homeowners should always check the furnace to make sure that the fan setting isn’t set to “on.”

The fan is in control of the furnace’s blower, which is what actually circulates the air in the home. When it is set to “on,” it is being told to constantly run, which means the air is getting circulated regardless of whether it has been heated or not. Homeowners should make sure it is set to “auto” instead, which will tell the furnace to only circulate heated air. When set to “on,” cold air coming from your HVAC unit isn’t a broken heater, just a simple setting error.

What To Do About an Overheated Heater

heating unit

Overheating furnaces can trigger the “high limit” switch, which tells the burners to turn off in an effort to stop the heat exchanger from potentially cracking and becoming a fire hazard. This can cause cold air to be pushed through your HVAC unit instead of hot. In this case, the reason may actually be a broken heater, which will require professional attention or even a potential replacement unit.

Other signs of a broken heater due to overheating include odd noises and smells, or a furnace that randomly turns off for no apparent reason. Overheating can be caused by a variety of factors like dust and dirt build-up in the furnace or on the air filter, motor failure, or simply age. Homeowners that suspect they are dealing with an overheated, broken heater should contact an HVAC professional for recommendations.

A Broken Heater May Just Be a Dirty Air Filter

dirty air filter next to a clean one

One other easy solution to what may wrongly be considered a broken heater is to check the air filter. When an air filter is too dirty, it can actually physically block the flow of hot air into the home. It can also lead to overheating, as mentioned above, along with significantly lowering air quality.

Air filters should be changed regularly, either by the homeowner or by a qualified HVAC technician. A general recommendation is that one to two-inch filters should be changed at least every three months, four-inch filters at four months, and five-inch filters once annually.

However, they should also be checked more regularly, and examined for any obvious dirt or debris. Homes with pets, young children, or people who suffer from either allergies or asthma should be especially aware of how clean their air filters are and change them even more regularly. Homeowners should contact a local Spanish Fork heating technician for specific recommendations based on their unique situation.

Let HRC Climate Services Help

The owners and staff at HRC Climate Services, located in Spanish Fork, Utah, have more than two decades of experience servicing HVAC units. They offer flat-rate pricing, emergency services, and trustworthy, honest recommendations for all their customers.