How to Replace a Radon Fan (DIY Guide)

When to Replace vs. When to Call a Pro

DIY-appropriate:

• Fan failure with no other system changes needed (same pipe, same suction point)
• Upgrading from XP201 to GX3 with the same pipe diameter
• Fan is in an accessible location (attic, garage, or exterior mount with easy access)
• You're comfortable with PVC pipe fittings and basic electrical connections

Call a certified contractor:

• You want to add or move a suction point (requires core drilling)
• Post-mitigation levels have been rising even with the fan running (system design issue, not just fan failure)
• The fan is in a difficult location (above a finished ceiling, exterior wall with no access)
• The system was installed by the previous owner and you have no documentation

Step-by-Step: DIY Fan Replacement

What you'll need:

• Replacement fan (correct model and pipe size)
• PVC pipe union fittings (if the original fan wasn't installed with unions) or a hacksaw and couplings
• PVC primer and cement
• Screwdriver and adjustable wrench
• Voltage tester (safety — confirm power is off before touching wiring)

Step 1: Power off

Unplug the fan from the outlet, or turn off the circuit breaker if hardwired. Confirm power is off with a voltage tester before touching any wiring.

Step 2: Photograph the existing installation

Take photos of the pipe connections, electrical connections, and fan orientation before disassembling. You'll thank yourself when reassembling.

Step 3: Disconnect the pipe

If the original installer used unions (the smart way), unscrew the union couplings above and below the fan. If the pipe is glued directly to the fan flanges with no union, you'll need to cut the pipe above and below the fan with a hacksaw. Cut far enough from the fan that the remaining pipe stubs are even and workable.

Step 4: Remove the old fan

If wall-mounted, unscrew the mounting bracket. The fan itself is just resting in the pipe connections once those are separated.

Step 5: Prepare the new fan

Match the inlet and outlet pipe connections to your existing pipe diameter. Use the adapter collar if stepping between 3" and 4" pipe. Install pipe union fittings on the new fan before mounting if the originals didn't have them — it makes the next replacement much easier.

Step 6: Connect the pipe

Apply PVC primer (purple) then cement to the pipe stubs and fan fittings. Push and twist to seat. Hold for 30 seconds. If you're using mechanical unions (gasketed, no cement), hand-tighten then wrench snug — don't overtighten.

Step 7: Mount and wire

Remount the fan in the same orientation as the original. Confirm the condensate drain port faces downward. Plug in or reconnect the electrical.

Step 8: Verify operation

Turn the power on. Confirm the fan is running (you'll hear it). Wait 5 minutes and check the manometer — it should show a differential (one column lower than the other). If the manometer shows no differential after 10 minutes, check for air leaks at the pipe connections.

Step 9: Post-replacement test

Run a 30-day short-term test after replacement to confirm levels are maintained. Fan performance can vary between models even when specifications are similar.

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