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Radon fan not working: troubleshooting checklist

Short answer: Start with power: a tripped breaker, GFCI outlet or switched-off disconnect is the most common reason a radon fan stops. If the fan has power but the manometer reads zero and you hear nothing, the fan has likely failed and needs replacing with a model sized for your system. Test your radon level once it is running again.

Safety: Turn off power before touching the fan. Hardwired fans and outdoor wiring should be handled by a qualified electrician. Radon fans must not be installed in or below living space.

Step by step

  1. Confirm it has stopped. Check the manometer (even liquid levels) and listen or feel at the fan housing. A radon system alarm, if fitted, will usually be sounding.
  2. Check power. Reset the breaker and any GFCI outlet the fan is plugged into, and make sure the outdoor or attic disconnect switch is on.
  3. Check the piping. Look for a separated coupling, a cracked pipe, or a blocked exhaust (snow, ice, a nest).
  4. Replace the fan if needed. Match the existing model, or ask a radon professional, because fans differ a lot in airflow and suction. Note the pipe size (3-inch or 4-inch) for couplings.
  5. Retest. Run a short-term radon test with the system running at least 24 hours first.

Replacement fans and kits

Common questions

How long do radon fans last?

It varies by model, climate and installation; fans run continuously, so they eventually wear out. Check your fan maker's warranty and literature.

Can I replace a radon fan myself?

Many fans connect with rubber couplings and hose clamps, so swapping a like-for-like fan is mechanical work. Wiring should follow local electrical code; when in doubt, hire a pro.

Should I turn the radon fan off in winter?

No. Radon systems are designed to run all the time.

Shop radon mitigation parts Replacing a radon fan

Related categories: Radon Mitigation Supplies. General information only; follow the equipment maker's instructions and local codes. Updated 2026-11-14.