What Are The 12 Most Common Furnace Problems?

Nothing is worse than having a furnace that has stopped working in the middle of a freezing night. Some minor furnace problems can be solved easily with a simple DIY, but you will need professional help for bigger and more significant issues.

To understand what to do in such situations, every homeowner should have basic knowledge about common furnace problems. 

A List Of 12 Common Furnace Problems That You Should Know

Thermostat Issues

Many homeowners often forget to check the thermostat when the furnace doesn’t work. They often call a professional only to find out that the thermostat was not turned on or set to heat. If you find your furnace isn’t working, the first thing to do is to check the thermostat.

Dirty Or Clogged Filters

A dirty or clogged filter can reduce your furnace’s efficiency as it restricts the necessary airflow which your furnace needs to function properly. It can lead to many problems, such as overheating and damage to the limit switch. In this case, ensure to replace these filters regularly.

Cracked Heat Exchanger

A cracked heat exchanger can lead to harmful carbon monoxide seeping into your home. Overheating and dirty filters are the primary causes of a cracked heat exchanger. The solution to this problem may be a bit expensive as it usually requires a professional for heat exchanger replacement.

Faulty Limit Switch

If you find your blower fan running continuously even when your thermostat is set to auto mode, something is wrong with the limit switch. To deal with this problem, contact Logic HVAC/R for a professional furnace repair in Denver

Unusual Noises

If your furnace makes popping, rattling, or pinging noises, it indicates a serious problem. These noises are produced due to different issues, and each noise indicates a specific problem. Thus it would be better to call a professional if you notice any unusual noise from your furnace.

Worn-Out Ball Bearings

The ball bearings of your furnace help the motor to work properly. However, over time, these bearings can wear out and need replacement. If you notice any scraping sound coming from your furnace, it means your ball bearings have worn out, and you should turn off the system immediately and call a professional.

The Furnace Isn't Blowing Air

Several issues could result in a furnace not blowing air. The primary one is a clogged blower. To solve this problem, ensure that your blower is clear of debris or call a professional if the problem continues.

Pilot Light Issues

If your pilot light is flickering or is a yellow color, it indicates an excess of carbon monoxide in the furnace. The pilot light is necessary for a furnace’s proper functioning, and you should not ignore any changes in it.

Malfunctioning Blower Belt

A blower belt helps your furnace’s fan in the running, but it may fray or break with overtime usage. If you notice a squealing sound, it indicates blower belt issues; and you need to replace this belt.

Frequent Cycling

A clogged filter, restricted airflow, or a too-high or too-low running furnace are the primary causes of a frequent cycling furnace responsible for your high energy bills.

Dirty Burners

The burners can get gunked up with overtime usage and need cleaning. Dirty burners can also result in no heating. Ensure your burners are clean by calling Logic HVAC/R and get the best heating services, like furnace replacement in Denver

The Access Panel Was Left Open

There is a panel on the unit which is used to access the guts of the furnace. Close this panel properly; otherwise, your furnace won’t turn on.


Suppose you are having any troubles with your furnace and need professional help. Contact us at Logic HVAC/R and get the best heating and cooling services, including furnace replacement in Denver. 

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