How to tell your system is working
Every properly installed system has a pressure gauge on the pipe, usually a U-tube manometer: a small U-shaped tube with colored liquid. When the fan is pulling suction, the liquid on one side sits higher than the other. When the installer finished, they should have marked the normal level.
- Uneven liquid levels: the fan is running and pulling suction. Good.
- Level liquid on both sides: the fan isn't pulling. It may have failed, lost power, or a breaker may have tripped.
- Reading much higher than marked: something may be blocking the pipe, such as ice at the exhaust or water in a low spot.
Glance at it every month or so, for example when you change the furnace filter.
Signs a fan is failing
- The manometer reads level.
- New rattling, grinding, buzzing or whining from the fan.
- The fan housing is hot or there's a burnt smell (turn it off at the switch and call a pro).
- A follow-up radon test comes back higher than before.
How long do radon fans last?
Radon fans run around the clock, so they wear like any motor. Lifespans vary by model, location and conditions; many manufacturers' warranties run around five years, and many fans last longer than that. Fans mounted outside face Kansas heat, cold and wind; attic fans face summer heat. Neither is a problem for a fan rated for it.
What replacement involves
Replacing a fan is usually a short job: the old fan is cut out or unclamped from the pipe, a new fan is fitted with rubber couplings, and the wiring is reconnected. The installer should check the manometer, confirm suction, and ideally recommend a follow-up test. Replacement is often a good time to ask whether a different model would suit your house better, for example a quieter fan, or a lower-wattage one if your suction needs allow.
Ask for the new fan's model and warranty in writing. In Kansas, radon mitigation work for someone else, including system repairs, should be done by a KDHE-certified mitigation professional.
Running cost
Many residential radon fans draw somewhere between about 20 and 150 watts. To estimate your yearly cost, multiply the fan's wattage by 8.76 to get kilowatt-hours per year, then by your electric rate. Your Evergy bill shows your rate per kWh.
Other upkeep
- Keep the exhaust clear of bird nests and, in winter, heavy ice.
- Don't let anyone cut, cap or reroute the pipe during a remodel without a radon pro involved.
- Keep the sump lid sealed if you service the pump.
- Retest every two years, and after major renovations, as the EPA recommends.
Need a fan replaced or a system checked? Send a request and mention "fan replacement" in the details.
Common questions
Can I turn my radon fan off in summer?
No. Radon enters all year. The system is designed to run continuously, and switching it off lets levels rise again within hours to days.
Is it normal to hear the fan?
A soft hum or airflow sound is normal, especially near the fan. New grinding, rattling or a loud whine usually means bearings are wearing and the fan should be checked.
Can I replace the fan myself?
It is physically simple, but the fan must suit the system, and in Kansas radon mitigation work for others must be done by a KDHE-certified professional. A pro can also confirm suction and recommend a follow-up test.