The part(s) or condition(s) listed below for the symptom Furnace not blowing enough are ordered from most likely to least likely to occur. Check or test each item, starting with the items at the top of the page.
Furnace Blower Not Running? Gas Furnace Troubleshooting
Furnace Blower Runs All The Time? Gas Furnace Troubleshooting
Furnace Noisy Or Loud? Gas Furnace Troubleshooting
Furnace Starts Then Stops? Gas Furnace Troubleshooting
Furnace Not Heating? Gas Furnace Troubleshooting
Replace Furnace Filters - Tech Tips from Repair ClinicSince the furnace's blower motor is the component that circulates the heated air through the home's venting, a defective blower motor will result in the furnace not blowing enough. You can use a multimeter to test the blower motor for electrical continuity, a continuous electrical path present in the motor, as well as determine if power is reaching the motor. You can also try turning the blower wheel by hand. If the wheel does not turn freely, it's likely the motor bearings have seized and the blower motor will need to be replaced.
Some heat registers have adjustable louvers that allow the air flow to be restricted or shut off entirely. This would be used to cut off the air flow to a room that isn't being used or to restrict air flow to one room so more
Over time the blower wheel and housing can become clogged with dust and debris. This will restrict the air flow, preventing the furnace from blowing enough. You can try cleaning the blower wheel with compressed air or with a soft bristle brush. Use caution when trying to clean the blower wheel as the fins are sharp and can be easily damaged. If the blower is damaged it will need to be replaced.
Over time the blower wheel can become clogged with dust and debris. This will greatly affect the air flow circulating throughout the home. You can try cleaning the blower wheel with compressed air or with a soft bristle brush. Use caution when trying to clean the blower wheel as the fins are sharp and can be easily damaged. If the blower is damaged it will need to be replaced.
The run capacitor provides voltage to the blower motor. If the capacitor is defective, the blower motor may not run resulting in the furnace not blowing enough. To determine if the capacitor has failed, test the capacitor with a multimeter. If the run capacitor is unable to hold and release a charge or is bulging or leaking, replace it.
The capacitor provides voltage to the blower motor. If the capacitor is defective, the blower motor may not run resulting in the furnace not blowing enough. To determine if the capacitor has failed, test the capacitor with a multimeter. If the capacitor is unable to hold and release a charge or is bulging or leaking, replace it.
Air Filter
