How to Maintain a Radon Mitigation System

The Complete Maintenance Checklist

Monthly (30 seconds)

Check the manometer. Look at the U-tube liquid gauge on the pipe. If both columns are at equal levels, the fan has failed and the system is not creating negative pressure. If one side is lower than the other, the system is running normally.

This is literally a glance. Mount the manometer where you'll see it naturally — on the pipe in the basement utility area or at the base of the pipe in the garage. Habit-stack it with something else: check it every time you take the recycling downstairs.

Annually

Inspect the exterior exhaust termination. Walk outside and look at where the radon pipe exits the home. Check for:

• Bird nests or insect hives blocking the opening (add a pest screen if not already present)
• Ice buildup at the termination in cold climates (can restrict flow in extreme cold)
• Any structure that's been added near the exhaust — a new deck, addition, or HVAC intake that now falls within the 10-foot clearance zone

Inspect the pipe run. Walk the interior pipe and check:

• All hangers are still secure (pipes can loosen from vibration over years)
• No visible cracks or separations in the PVC or fittings
• The fan housing has no visible moisture damage or corrosion

Test your backup warning device. If your system has a separate warning device beyond the manometer, test it per manufacturer instructions.

Every 2 Years

Retest with a long-term alpha track kit. Place a 90-day kit in the same location as your original post-mitigation test. This confirms the system is still performing at the same level, accounts for seasonal variation, and provides updated documentation.

Radon levels can creep up over time due to:

• Fan performance degradation (slower fan = less negative pressure)
• New radon entry points from foundation settling or renovation
• Changes in sub-slab conditions

A biennial retest catches these drift scenarios before they become a health problem.

When to Replace the Fan

Replace immediately when:

• Manometer goes flat: Fan has failed — same-day or next-day replacement
• Unusual noise: Grinding, rattling, or high-pitched noise indicates bearing wear or debris in the impeller
• Retest shows levels rising: If a 2-year retest shows levels 50%+ above your original post-mitigation baseline, check the fan performance before assuming you need a new suction point

Replace proactively after 10–12 years of continuous operation, before failure. Fan replacement is far cheaper than discovering a failure via elevated radon on a real estate inspection when you're trying to sell.

Fan Replacement Cost

• DIY fan swap (same footprint): $150–$400 for the fan, 1–2 hours of work
• Contractor replacement: $300–$700 total
• Upgrade (XP201 → GX3): $250–$500 materials; consider if post-mitigation levels were marginal on the original installation

Keep your fan model and installation date written down somewhere permanent — on the pipe itself with a paint marker, in your home's maintenance file, or photographed and saved in cloud storage.

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