Reduced furnace airflow results in a cold house and often higher energy bills as well. Sometimes the issue is simple to repair, while in other cases you may need the help of a professional furnace repair technician.

1. Clogged Filter Housing

Filter issues are the most easily repairable cause of airflow loss. Keep in mind that it is not always just as simple as replacing the filter, though. Dust, pet hair, and other debris doesn't just get trapped in the filter. It may also become lodged in the housing for the filter or the vent cover over the filter. Your vacuum is the best way to solve the problem. Each time you change the filter, take a few minutes to vacuum out the filter housing, any ducts or lines leading from the housing, and any vent covers over the housing. Either use the hose attachment on the vacuum or use a shop vacuum to do a thorough job.

2. Duct Leaks

Leaks in the ductwork can also lead to a major reduction in furnace airflow. Leaks can be present due to construction mistakes, or they can develop over time. This is because metal ducts flex in response to the temperature changes of the air flowing through them. This flexing motion can cause ducts to work apart and develop gaps, which allows heated air to escape into the walls but not into the rooms that you want to heat. A duct leak test or camera inspection is necessary to locate leaks. If leaks are found, your furnace tech can repair the damaged ducts or seal the leaks to minimize heat loss.

3. Blocked Vents & Returns

Vents and air returns can be blocked by furniture, drapes, or other items, but they can also be blocked internally. Some vents are equipped with levers that allow you to open and close the vents. Make sure that these vent types are always set to be fully open if you want maximum airflow. Further, dust and debris can fall into floor vents and cause a partial blockage that reduces airflow. Using a hose attachment to vacuum out the vents periodically helps, but you may also benefit from a full duct cleaning.

4. Blower Failure

A failing blower may not be immediately obvious because the furnace will still kick on and you will hear it running. It may just seem to run longer than usual or your home may not get as warm as it should. In some case, a failing blower may also become noisier, but this isn't always the case. It's important to have the furnace inspected annually so issues with the blower can be discovered and fixed before total airflow loss becomes a problem.

Contact a furnace repair service in your area if you have noticed a loss of airflow from your furnace.