WM Henderson Truck


Why Is There Low Air Flow from My Furnace?

Why Is There Low Air Flow from My Furnace?

From dirty air ducts, blocked damper valves, damaged duct runs, to an insufficient numbers of return air vents, there are a variety of signs that may indicate a furnace air flow issue in your home. If you notice something wrong—such as the furnace not blowing hot air properly—please take it seriously and call for furnace service from our trained and licensed technicians.

Our expert technicians are here for youSchedule Online Today

Obstructions in Air Ducts

If your furnace is not blowing air through the vents in your home, the source of the poor air flow may be an ineffective air filter. Air filters are designed to block materials such as dirt, dust, and grime from entering your air duct system. However, air filters are not always able to trap all types of materials that travel through your heating system. A small amount of dirt and grime is able to bypass the air filter in your HVAC system. Overtime, this excess dirt will stick to the air ducts in your home and cause furnace air flow issues. We recommend consulting with a professional HVAC technician on ways to increase the air flow in your air ducts throughout your home.

Furnace Issues in the Winter SeasonBlocked Damper Valve

Are you wondering how to increase air flow in your air ducts? If the air flow from your furnace or air conditioner is low in various rooms throughout your home, it is likely caused by a blocked damper valve. Dampers are designed to regulate air flow throughout the floor plan of your home. A damper valve is able to transmit air flow along specific paths of your home to ensure warm or cold air is able to reach certain locations. If the furnace is not blowing hot air in a specific area of the home, this may be an indicator of a closed damper valve.

Read More: Improve Your Air Quality this Winter With a Whole-Home Humidifier

Automatic Damper Valve

If your home features automatic damper valves, they will be automatically opened and closed by your thermostat during standard operation. Limited air flow in particular rooms of your home may be an indicator that the damper valve is stuck. We recommend scheduling an appointment with a professional HVAC technician to receive assistance with a closed damper valve.

Manual Damper Valves

Unlike automatic damper valves, manual dampers are not controlled by your thermostat. A manual damper valve needs to be opened or closed by the homeowner or a professional. If there is a room in your home that has insufficient air flow, you will be required to locate the closed damper in your air ducts. While you are searching for the ineffective manual damper, keep an eye out for a small lever that is designed to control the damper position. Continue searching through your air ducts until you find the area that is responsible for low furnace air flow in your home.

Return VentLimited Number of Return Air Vents

The return air vents in your home are designed to absorb the warm air produced by your furnace that is distributed through your primary vents. If your furnace is not blowing air through the vents in your home, this may be due to a limited amount of return air vents. A lack of return vents will cause low furnace air flow issues because your HVAC system is not receiving the same amount of air back that it originally distributed throughout your home. This will cause the air throughout the rooms of your home to become pressurized. Low air flow may also be caused by an obstruction within the return air vent that is blocking air from leaving an individual room. Regardless, it’s best to work with a professional HVAC contractor to restore the furnace air flow in your home.

Damaged or Misconfigured Duct Runs

The duct runs in your home are engineered to transmit a specified amount of conditioned air to each room. If the furnace is not blowing hot air in your home, this is a sign of damaged or disconnected air ducts. Damage to a run or piece of flex will cause rapid temperature fluctuations throughout the home.

Read More: What is a P-Trap Plumbing Pipe?


Holes in the Air Ducts

As the duct work system becomes older in a home, it will start to develop cracks and holes. The average household is able to lose up to 50% of conditioned air from leakage issues. This will cause low furnace air flow issues and will drastically affect your heating bills. There are two types of air duct leaks that are able to form in homes.

The first type of air duct leak will cause conditioned air to leak into unintended rooms of your home. Instead of making its way to the optimal room, the air leaks through the air duct into the incorrect room. This is not a huge issue because the warm air is still able to make its way throughout the home. The second type of air duct leak consists of conditioned air escaping into exterior locations such as the attic, crawlspace, or outdoors. Talk to a heating technician to confirm if you have an air duct leak in your home.

Heating Repair & Installation Services

If you’re not able to confirm the source of your air conditioner or furnace air flow issues, give us a call by phone at (484) 206-8594 to receive assistance. We offer a variety of heating services such as furnace repair, boiler installation, heating system replacement, heat pump maintenance and furnace replacement in areas of Pennsylvania such as Havertown, Drexel Hill, West Chester, Broomall, Wayne, and Springfield. Do you need help choosing a new heat pump or furnace for your house? Our team will help you compare and choose a new heating system for your house.