Effective Dacono Radon Mitigation

A fan motor that hums but does not spin typically indicates that the run capacitor has failed. The capacitor provides the electrical boost needed to start the motor spinning, and without it, the motor receives power but cannot overcome its own inertia. Running a motor in this condition for extended periods can cause it to overheat and burn out the windings, turning a capacitor replacement into a full fan replacement. Because capacitor replacement requires electrical work and the repair cost often approaches the cost of a new fan, most contractors recommend replacing the entire fan unit when this issue arises.

The easiest way to check fan operation is to look at the visual flow indicator, or U-tube manometer, which is a small liquid-filled gauge installed on the suction pipe. When the system is working correctly, the fluid column should be uneven, showing that negative pressure exists in the pipe. You can also place your hand near the exhaust pipe termination outside to feel for airflow. If you are unsure, a certified radon contractor can perform a full diagnostic test using a digital manometer to precisely measure system suction.

The clearest sign that a radon fan needs replacement is when it stops running entirely, which you can confirm by checking the manometer and listening for motor noise. Other warning signs include excessive humming or grinding, significantly reduced suction on the manometer, or radon test results that have climbed above 4 pCi/L despite the fan appearing to run. Age is also a factor, as fans over 10 years old are statistically more likely to fail and may be worth proactively replacing even before issues arise.