Finding Duct Leaks

Possible Reasons Why Your Furnace Overheats

Do you notice unusual humming sounds or a burning odor that emanates from your home's cooling vents? Then, your furnace is probably overheating. Although your furnace's job is to heat your home when temperatures plummet, the unit itself shouldn't get hot. 

Luckily, your furnace shuts off when it overheats, thanks to a built-in safety feature. Still, a furnace that overheats consistently eventually breaks down. So, you should correct the problem before things take a turn for the worst. 

Discover common reasons why your furnace overheats. 

Airflow Issues

Poor ventilation causes your furnace's internal components to overheat. A dirty air filter is a common culprit for restricted airflow in your furnace.

Generally, an air filter's purpose is to trap all dust, mites, debris that try to enter your furnace. Over time, dust and debris build-up can impede airflow, and your furnace strains to pull air in. Eventually, your furnace overheats and may trip your circuit breaker.

With a clean air filter, these contaminants will not clog your furnace's ventilation system. So, to prevent airflow issues, inspect your air filter monthly. Also, replace an overly clogged air filter to allow unrestricted airflow through your furnace.

You should replace your air filter more often if:

  • You recently finished a renovation project
  • A household member smokes indoors
  • You have more than one pet

A healthy air filter reduces the strain on your furnace. Better still, a clean air filter promotes excellent indoor air quality, which is crucial if you suffer from asthma and allergies.

Short Cycling

Furnace short cycling happens if your furnace switches on and off repeatedly before it produces sufficient warm air to keep your home comfortable. Oftentimes, furnace short-cycling occurs when the heat exchanger overheats and triggers the high-limit switch as a safety precaution. 

A wrongly sized furnace also causes short cycling. An oversized furnace utilizes too much energy to heat your home. Consequently, the furnace heats your home quickly then turns off. With poorly distributed warm air in your house, your furnace switches on again shortly after, and the trend continues. The best way to tame short cycling is to invest in an appropriately sized furnace for your home.  

Additionally, a faulty thermostat can cause your furnace to stop prematurely, run continuously, or not start at all. You should call a professional right away to fix these issues. Also, check the location of your thermostat. If you install the thermostat near your furnace, an oven, or in direct sunlight, the temperature fluctuations can trigger frequent short cycles. 

Furnace short cycling stresses your furnace motors and causes them to overheat. Never ignore short cycling issues as they might result in total system failure. 

Prompt furnace repairs will keep your furnace functional when you need it the most. Also, keep to regular furnace maintenance to catch issues early before they become a nightmare.