Radon Guide
Radon Mitigation System Maintenance
Radon mitigation system maintenance is one of the lightest jobs an Iowa homeowner has: no filters, no annual service contract, and a fan that runs for years. But it is not nothing, and a system that quietly stopped working looks exactly like a system that is working.
A radon mitigation system needs three things. Look at the warning device on the vent pipe regularly, retest the home at least every two years, and expect the fan to need replacing after about five years. There are no filters to change. Everything else is watching for the signs the system has stopped pulling.
What Maintenance Does a Radon Mitigation System Need?
Very little, by design. An active sub-slab depressurization system, the standard fix in Iowa, is a pipe, a continuously running fan, and a gauge. There is no filter, no fluid to top up, and no moving part a homeowner is expected to touch. The EPA's own guidance for homeowners comes down to two habits: look at the warning device on a regular basis to make sure the system is working correctly, and retest the home at least every two years to be sure radon levels remain low.
The reason the light workload still matters is that a radon system fails silently. The fan is quiet when it is healthy, so a homeowner cannot hear the difference between running and stopped from inside the house. Radon has no smell and no color, so the air does not change in any way a person can detect. The gauge and the retest are the only two things standing between a failed system and years of exposure nobody noticed.
That risk is larger in Iowa than almost anywhere else. All 99 Iowa counties are designated EPA Radon Zone 1, the highest-risk category, and Iowa HHS reports a state average indoor level around 8.5 pCi/L against a US average near 1.3 pCi/L. A system that stops working in an Iowa home is not drifting back to a safe baseline. It is drifting back to one of the highest radon baselines in the country.
Radon Mitigation System Maintenance Schedule
The whole schedule fits in four rows. Nothing here requires a contractor except the fan replacement, and nothing here needs doing more than a few times a year.
| Task | How often | Why |
|---|---|---|
| Look at the warning device | Regularly, all year | The EPA advises looking at the warning device on a regular basis to confirm the system is working correctly. On most Iowa systems this is the U-tube manometer on the vent pipe. |
| Retest the home | At least every two years | The EPA states it is a good idea to retest at least every two years to be sure radon levels remain low. Also retest after foundation work or a major renovation. |
| Plan for a new fan | Around the five-year mark, then as needed | The EPA notes fans may last five years or more, and that manufacturer warranties tend not to exceed five years. |
| Look at the vent pipe outside | After heavy snow or a storm | Practical Iowa winter housekeeping rather than a code duty. Ice, a nest, or storm damage at the discharge point stops the system venting where it was designed to. |
Your Five-Minute Radon Mitigation System Maintenance Check
The check is one look at the gauge and one look at the pipe. The EPA advises looking at the warning device on a regular basis to make sure the system is working correctly, and on most Iowa installations that warning device is a small U-shaped tube of colored liquid mounted on the vent pipe, called a manometer.
Read the manometer
The manometer measures suction, not radon. When the system is pulling, the liquid sits at two different heights, and the gap between them is the reading. Note where those columns sit while you know the system is healthy, ideally by photographing the gauge after installation. That photo is the baseline every later check is measured against.
- Columns uneven, matching your baseline. The system is pulling suction as designed.
- Columns level with each other. Usually a loss of suction, often a failed fan, a leak, or a blockage. Worth diagnosing.
- Reading has drifted from the baseline. Something has changed in the system. A specialist can find what.
Check the fan is running
Radon fans are mounted outside the living space, in an attic, a garage, or on an exterior wall, and they run continuously. A light touch on the fan housing should find a faint vibration. Silence and stillness at the fan, paired with a level manometer, point the same direction.
Look at the discharge point outside
Walk outside and look up at the top of the vent pipe. It should be open and clear. This is practical housekeeping rather than a code duty for the homeowner, and it matters most after an Iowa winter storm: ice, a nest, or storm damage at the discharge point stops the system venting where it was designed to.
Never switch the fan off to inspect it and leave it off. The system works because it runs continuously, and levels can climb back within days.
How Long Does a Radon Fan Last, and What Does Replacement Cost?
The EPA states that fans may last for five years or more, that manufacturer warranties tend not to exceed five years, and that replacing a fan will cost around $200 to $350 including parts and labor. That EPA estimate is a national figure. Published Iowa pricing for a fan replacement commonly runs somewhat higher, roughly $300 to $600 including the fan and labor. Both are third-party market figures, not prices set by Iowa Radon Professionals.
The practical read on those numbers: the fan is the one part of the system with a predictable end of life, and five years is a planning horizon rather than a deadline. Many fans run longer. What matters is that once a system passes the five-year mark, the manometer check stops being routine and starts being the thing that catches the failure.
A replacement is not a whole new system. The piping, the sealing, and the suction points stay. A credentialed specialist sizes the new fan to the home's pressure field, fits it, and retests to confirm the level came back down. If your system is showing its age, our radon fan replacement and system repair page covers what that visit involves, and the radon mitigation cost in Iowa guide sets it against the cost of the original install.
What Iowa Rules Say About Your Installed System
Iowa does not leave the mitigation standard to the installer. Iowa Administrative Code chapter 641-44, rewritten effective July 1, 2026, requires a credentialed person to comply with the ANSI/AARST mitigation standards as amended to August 1, 2025, and names ANSI/AARST SGM-SF-2023, Soil Gas Mitigation Standards for Existing Homes, as the standard for existing houses. Three parts of that chapter are worth a homeowner's attention long after installation day.
You should have an operation and maintenance package
Chapter 641-44 requires a credentialed specialist to provide the building owner with an operation, maintenance and monitoring information package for the system installed, with contents drawn from the applicable ANSI/AARST standard, and it requires that package to include the phone number for the Iowa radon program. If you have never seen yours, that is the first document to ask the installing company for. It is the closest thing your system has to an owner's manual.
The system was meant to get you below 4 pCi/L
The chapter requires a credentialed person to install a mitigation system that reduces the radon level to below 4 pCi/L in the area or level of the building where the system is installed. It also lists accepting compensation for installing an ineffective remedy, or for not dropping levels below 4 pCi/L, among the grounds for enforcement action against a credential. That is the benchmark a later retest is measured against.
Testing before and after is the default
The chapter requires the credentialed person to ensure each building is tested for radon before and after mitigation work, unless the building owner waives that testing in writing beforehand on a form furnished by the department. Specialists must keep a record of each mitigation activity for a minimum of five years, so the paperwork on an older system may still be retrievable from the company that installed it.
Who Can Service a Radon Mitigation System in Iowa?
Anyone paid to do the work needs an Iowa credential. Rule 641-44.3(1) states that, except as provided in that chapter, no person may mitigate for radon or radon progeny in Iowa for a fee or other remuneration unless that person has been credentialed by the department, and it adds that the requirement applies to businesses based in Iowa and to businesses based in another state that offer radon mitigation services to Iowa residents. The rule reaches the handyman quoting a cheap fan swap just as much as it reaches a radon company.
The chapter exempts persons who mitigate in buildings they occupy, so a homeowner working on their own house is outside the credentialing requirement. It also treats functioning as a radon mitigation specialist in violation of Iowa Code chapter 136B as a serious misdemeanor, which is the weight Iowa puts behind the credential.
Iowa HHS publishes a list of credentialed radon mitigation specialists, each with a certification number. Checking the name on the quote against that list takes a minute and is the cleanest verification available in this trade. Two further checks before work starts, covered in our guide to choosing an Iowa radon contractor: confirm the specialist carries their own insurance, and confirm a post-work test is included so the repair is proven rather than assumed.
Iowa Radon Professionals is a marketing service, not a contractor. We do not service, repair, or install radon systems. We connect Iowa homeowners with independent NRPP-certified, Iowa HHS-credentialed specialists, and those credentials belong to the specialist rather than to us.
Signs Your Radon Mitigation System Maintenance Is Overdue
Any one of these is a reason to have the system looked at, and none of them are worth waiting out.
- The manometer columns are level. The most common single sign, and it usually means suction has been lost.
- The fan is silent and still. Radon fans run continuously. A stopped fan is a stopped system.
- The fan has become noticeably loud. A change in sound from a fan that ran quietly for years suggests wear in the motor or bearings.
- A new test comes back at or above 4.0 pCi/L. The EPA action level, and the level Iowa's rules expect a system to hold the home below.
- The system is past five years and has never been rechecked. Past the point where the EPA notes warranties tend to end.
- The vent stack is blocked, iced, or damaged. Common after an Iowa winter or a storm.
The next step for any of these is a diagnosis, not a replacement, since a level manometer can come from a leak or a blockage as easily as from a dead fan. Our radon system repair page explains how a credentialed specialist finds the cause, and a radon testing result afterwards is what confirms the home is back below the action level.
Frequently Asked Questions
Does a radon mitigation system need maintenance?
Yes, but very little. There are no filters to change and no annual service visit required. The routine is to look at the warning device regularly, retest the home at least every two years as the EPA advises, and expect the fan to need replacement eventually, since the EPA notes fans may last five years or more and manufacturer warranties tend not to exceed five years.
What does it mean if my radon manometer is level?
On most systems the manometer is the warning device, and two liquid columns sitting at the same height usually mean the system is no longer pulling suction. Common causes are a failed fan, a leak, or a blockage. It is a reason to have a credentialed specialist diagnose the system, and to retest the home.
How often should I retest after radon mitigation?
The EPA states it is a good idea to retest your home at least every two years to be sure radon levels remain low. Retesting is also sensible after foundation work, a major renovation, or any repair to the mitigation system itself.
How much does it cost to replace a radon fan?
The EPA estimates that replacing a fan will cost around $200 to $350 including parts and labor. That is a national EPA figure. Published Iowa pricing for a fan replacement commonly runs somewhat higher, roughly $300 to $600. Neither figure is a price set by Iowa Radon Professionals, and the specialist quotes after diagnosing the system.
Can I work on my own radon mitigation system in Iowa?
Iowa rules govern paid work. Iowa Administrative Code rule 641-44.3(1) states that no person may mitigate for radon or radon progeny in Iowa for a fee or other remuneration unless credentialed by the department, and rule 641-44.10 exempts persons who mitigate in buildings they occupy. So a homeowner working on their own home sits outside the credentialing requirement, while anyone paid to do the work does not.
What paperwork should I have for my radon system?
Iowa requires a credentialed mitigation specialist to provide the building owner with an operation, maintenance and monitoring information package for the system installed, and that package must include the phone number for the Iowa radon program. If you cannot find yours, it is worth asking the company that installed the system for a copy.
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