St. Louis Metro · Missouri & Illinois
Radon System Maintenance
Radon system maintenance is the routine checking of a radon mitigation system’s fan, manometer, piping, and seals, plus a radon retest at least every two years as the EPA recommends.
Radon systems are close to maintenance-free by design, but they are not maintenance-none. Fans run continuously and eventually wear out, and a failed system gives no indication other than a manometer whose fluid has gone level.
Air Sense Environmental services systems we installed and systems installed by other contractors across the St. Louis metro, on both the Missouri and Illinois sides.
What Maintenance Protects
Systems are engineered to bring your home below the EPA action level of 4.0 pCi/L.
Serviced any brandOwner Checks
What does radon system maintenance involve?
Radon system maintenance involves a short visual check a few times a year plus a radon retest every two years. Most of it is something a homeowner can do without tools.
- Read the manometer. Uneven fluid columns mean the fan is pulling. Level columns mean it is not.
- Listen to the fan. A new rattle, a changed pitch, or silence all warrant a look.
- Inspect visible piping. Check for cracks, disconnected couplings, and sagging that could trap condensate.
- Check the seals. Look at the sump lid, slab penetration, and floor-wall joint for gaps that have opened.
- Confirm power. The fan should never be switched off, and a tripped breaker will stop it silently.
- Retest. The EPA recommends retesting at least every two years after mitigation.
Reading the gauge takes about ten seconds. Our page on the radon manometer covers exactly what the fluid levels mean.
Schedule
How often does a radon system need maintenance?
Check the manometer a few times a year, retest the home at least every two years, and expect the fan to need replacement after several years of continuous operation.
A workable schedule:
- Seasonally, especially at the start of the heating season when radon levels are naturally highest
- After a power outage, since the fan may not restart if a breaker tripped
- Every two years, a radon retest per EPA guidance
- Before selling, since a buyer’s inspector will check the system and often request a fresh test
- After foundation work, which can open new entry pathways or disturb existing seals
Wear
How long does a radon fan last?
Radon fans generally last several years of continuous running before they fail, and replacement is a single-visit job in most cases.
Signs a fan is nearing the end:
- The manometer columns have levelled out, the clearest sign of all
- The fan has gone silent, or its hum has changed pitch
- A new rattle or vibration from the pipe
- A cracked fan housing, or water intrusion into it
- A radon retest that came back higher than the previous one
Fans should be replaced with a unit sized to the system rather than whatever matches the pipe diameter. See radon fan replacement for what that involves.
Verification
Why does a radon system need retesting?
A radon system needs retesting because the manometer measures pressure in the pipe, not radon in the air, and those are not the same thing.
A system can hold perfectly normal suction while a house drifts back above the EPA action level of 4.0 pCi/L. Foundations settle and open new pathways, seals degrade, renovations cut into slabs, and additions change how air moves through the building. None of that shows up on the gauge.
The EPA recommends retesting at least every two years after mitigation, and after any significant renovation or foundation work.
Other Installers
Can you service a radon system another company installed?
Yes. Air Sense Environmental services radon systems installed by other contractors as well as systems we installed ourselves.
This comes up often, because radon systems outlive the companies that install them. If the original installer is out of business or unresponsive, the system can still be assessed, the fan replaced, and the house retested without rebuilding the installation from scratch.
Where we find deeper problems, such as a suction point that never depressurized the full slab, we say so before doing any work rather than replacing a fan on a system that was never going to perform.
Local Service
Radon system maintenance across the St. Louis metro
Air Sense Environmental provides radon system maintenance throughout the St. Louis metro, including St. Louis City and County, St. Charles County, Jefferson County, and Franklin County in Missouri, and Madison and St. Clair counties in Illinois.
Local conditions do affect service intervals. Systems on exterior walls face freeze-thaw cycles that interior runs do not, and older St. Louis foundations tend to open new pathways as they settle, which is worth catching at a retest rather than years later. Illinois requires radon professionals to be licensed through IEMA, and Air Sense Environmental holds license #RNM20232346.
See our service area for the communities covered, or radon mitigation for the systems themselves.
Common Questions
Frequently Asked Questions About Radon System Maintenance
Does a radon system need annual servicing?
A radon system does not need a scheduled annual service visit the way a furnace does. It needs a manometer check a few times a year, which the homeowner can do, and a radon retest at least every two years as the EPA recommends. Professional service is called for when the manometer reads level, the fan is noisy, or a retest comes back elevated.
Can I turn my radon fan off to save electricity?
No. A radon fan is designed to run continuously, because radon enters from the soil continuously, and levels climb back toward pre-mitigation readings within hours of the fan stopping. The fan costs roughly $50 to $150 a year to run, which is why switching it off is not a worthwhile trade.
How much does radon system maintenance cost?
Radon system maintenance costs nothing for the routine part, since reading the manometer and listening to the fan are things a homeowner does without tools. The radon system maintenance costs that do arise are a radon retest every two years and, eventually, fan replacement after several years of continuous running. Air Sense Environmental quotes any radon system maintenance work before starting, so there is no open-ended charge.
What happens if I never maintain my radon system?
If you never maintain your radon system and it fails, indoor radon returns to roughly its pre-mitigation level, with no smell, sound, or symptom to indicate it. Skipping radon system maintenance does not make the system look broken, because it continues to look installed, which is why failures often surface only during a real estate transaction. A level manometer is the one visible sign, which is why checking it is the core of radon system maintenance.
Do I need to retest radon after replacing the fan?
Yes. A radon retest after a fan replacement confirms the new fan is actually holding the house below the EPA action level of 4.0 pCi/L, rather than just confirming that a fan is running. Pressure at the manometer indicates the system is pulling, but only a test measures the radon concentration in the living space.
References: EPA radon action-level guidance and A Citizen’s Guide to Radon.
Not Sure It Is Still Working
Have your radon system checked
If the manometer has levelled out or the fan has gone quiet, we can usually diagnose and replace in a single visit, on any brand of system.