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Having Temperature Problems? It May Be a Clogged Air Filter

Airflow is one of the most important functions of an HVAC system, because equipment life, utility costs, and comfort are all impacted by the system airflow rate. When your furnace's airflow is reduced, you may experience temperature problems such as uneven air distribution in your home. If this is the case, you'll need to have your system inspected by a professional to figure out what's going on.

Why Do Furnace Airflow Problems Occur?

A furnace's airflow rate can be reduced for a couple of reasons. Most often, it reduces because of a clogged air filter, or because there are gaps or cracks in the system's ductwork.

How to check for a clogged air filter or cracks in the ductwork

  • Find the filter in your furnace. Filters will always be on the return side (where the air flows into the furnace). Typically, they are just beside, above, or below the furnace itself. In some cases, you may need to remove an access panel to see it. If you do need to remove a panel, ensure the furnace is turned off beforehand.

    Once you've found it, check to see if the filter looks grey. If there's dirt and dust buildup on the filter, it's time to change it.

    CAUTION: Be sure to turn the power off to any piece of HVAC equipment before removing access panels to avoid injury from rotating parts.

  • Go throughout your home and check on the vents in each room. Are the registers in those vents open all the way? If not, open them to see if the issue improves.

    While you're checking the registers, keep an eye out for furniture placed over or near a register, which will also affect air circulation. Keep that in mind when arranging furniture in a room.

  • Your ventilation system works efficiently when the air is delivered directly to the conditioned spaces and not lost along the way due to unintended openings, gaps, or cracks in the ductwork. Inspect your air return and supply vents to see if you see any cracks or gaps in the ductwork feeding them. If there are visible cracks or gaps, air is escaping from your ducts, which will cause poor airflow and distribution.

  • It can sometimes happen that your ductwork is too big (wide) or too small (narrow) to handle the airflow requirement of your heating and cooling system and your home. Have your system inspected by an HVAC professional to find out if you are using under or oversized ductwork.

  • Have you been using the filter for longer than six months?

  • Check that the unit’s air filter is clean and that the indoor air vents aren't blocked by furniture or other objects. Once the inside areas are clear, remove any debris around the outside unit like leaves, sticks, snow, or dirt that could be blocking air or the outdoor coil. Restricted airflow can cause the heat pump to freeze over.

If these steps didn't point you in the right direction, consider other sources of whistling from the ducts.

What To Do If Your Furnace's Airflow Is Causing Temperature Problems?

The solution to restoring proper airflow in your home's system depends on the issue's source. If you are dealing with a clogged filter, you'll need to replace it, and your airflow should return to normal levels.

If changing the filter doesn't restore airflow patterns, you've probably got cracks in your ductwork, a broken air handler, or something more complicated that will require a technician's expertise. You can reach out to our Remote Assist expert for a virtual diagnosis.

NOTE: This content is for informational purposes only, and HomeX and its affiliates disclaim all liability related to it. If you decide to perform any tasks based on this information, you assume all risks, including the risk of loss or damage to property or personal injury.

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