A radon fan is the part of an active system that does the work, so when it stops, radon can build back up. EPA says the fan should never be turned off and must run all the time for the system to work [1]. This page covers how long fans last, what replacement costs, and the Iowa rule that applies to changes.
Signs it's time
The gauge on the pipe is the first thing to check. EPA says to look at your warning device, usually a manometer, on a regular basis [1]. If it shows no suction, the fan may have failed. A retest is the other check. EPA suggests retesting at least every two years [1].
How long fans last
Sources differ here:
- EPA says fans may last five years or more, and manufacturer warranties tend not to exceed five years [1].
- HomeGuide gives 5 to 10 years for the fan and says most makers offer a 5-year warranty [2].
- Angi's fan guide says a well-kept fan lasts 5 to 10 years and that most new fans carry a 3- to 5-year warranty [3].
If yours is still under warranty, check that before paying for a new one, as Angi suggests [3].
What replacement costs
Angi's national October 2026 fan guide puts the average at $350, with most homeowners paying $200 to $600 [3]. It prices by fan size [3]:
| Fan size | Typical use | Published range |
|---|---|---|
| Low CFM (50 to 100) | Small homes, one suction point | $200 to $350 |
| Standard CFM (100 to 200) | Average homes | $300 to $500 |
| High CFM (200 to 300) | Large homes, high radon or complex systems | $400 to $600 |
Angi also lists labor at $50 to $100 an hour, permits where required at $25 to $150, and a retest after replacement at $20 to $100 [3]. These are national figures, not local ones.
The Iowa rule on changes
Iowa's mitigation rule, 641-44.2, defines a "radon system modification" as a change to an active system that alters its design, configuration or operation, such as adding or relocating piping, fans or suction points. The rule says this "does not include routine replacement of parts with equivalent components that do not affect system function or layout" [4].
So under Iowa's rule, swapping a fan for an equivalent one that doesn't change how the system works or its layout isn't a modification. Upsizing the fan, moving it, adding suction points or re-routing pipe is, and paid work of that kind needs an Iowa-credentialed mitigation specialist [4, 5]. People working on a home they live in are exempt [4]. Iowa HHS publishes the list of credentialed specialists, generated September 24, 2026 [6]. More on how it works.
FAQ
My fan is loud. Is that a failure?
Not always, but noise plus a flat gauge reading is worth a call. Angi says repairs run $75 to $200 and suggests replacing once a repair would top half the replacement cost [3].
Should I retest after a new fan?
Yes. Angi lists a retest after replacement as part of the job [3].
Get a quote
Request a fan replacement quote and tell us what the gauge shows.
We're a referral service, not a contractor. We send mitigation requests only to contractors on Iowa HHS's current credentialed list and testing requests only to state-certified radon measurement specialists, but we don't otherwise vet them, a referral is not an endorsement, and independent contractors may pay us for referrals.
Sources
- U.S. EPA, Consumer's Guide to Radon Reduction, EPA 402/K-10/005 (2025 edition, PDF). https://www.epa.gov/sites/default/files/2016-12/documents/2016_consumers_guide_to_radon_reduction.pdf
- HomeGuide, "How Much Does a Radon Mitigation System Cost? (2026)," Kristen Cramer, Feb 5, 2026. https://homeguide.com/costs/radon-mitigation-cost
- Angi, "How Much Does It Cost to Replace a Radon Fan? [2026 Data]," Angi Home Solutions Center, updated Oct 15, 2026. https://www.angi.com/articles/radon-fan-replacement-cost.htm
- Iowa Administrative Code 641, Chapter 44, Radon Mitigation (ARC 0290D, IAB 5/13/26, effective 7/1/26). https://www.legis.iowa.gov/docs/iac/chapter/641.44.pdf
- Iowa Code chapter 136B, Radon Control (2026). https://www.legis.iowa.gov/docs/code/136B.pdf
- Iowa HHS, Iowa Credentialed Radon Mitigation Specialists list (PDF, report generated 9/24/2026). https://hhs.iowa.gov/media/7883/download?inline