Buying a Lincoln Home That Already Has a Radon System
September 2, 2026
A mitigation system in the listing is a real plus — as long as it is actually working. How to check the fan, the pipe, and the paperwork during the inspection period.
An existing system is a head start, not a guarantee
Plenty of Lincoln listings now mention a radon mitigation system, and that is a point in the house's favor: someone measured, got a number they did not like, and dealt with it. What the line in the listing does not tell you is whether the fan still runs, whether the system was ever verified with a follow-up test, or whether anyone has looked at it since the install.
Houses with existing systems tend to go unwatched precisely because everyone assumes the problem is handled. The inspection period on a purchase is the natural moment to check, while questions still cost nothing and fixes can still be negotiated.
Start at the manometer
The quickest health check is the manometer — the small U-shaped tube of colored liquid mounted on the pipe, usually in the basement or garage. When the fan is pulling suction, the two liquid columns rest at different heights. When they sit level, the system is moving no air at all: the fan is off, failed, or the pipe is blocked.
Two things the manometer cannot tell you: what the radon level in the house actually is, and whether the suction was ever strong enough to bring that level down. It measures pressure in the pipe, nothing more. Treat it as a pass-fail light, not a result.
Walk the system from slab to roofline
With the manometer read, trace the rest of the system the way an inspector would:
- Suction point — the pipe should enter the slab, a sealed sump lid, or a crawl space membrane, with intact caulking where it penetrates. Gaps around the entry bleed away suction.
- Fan location — attics, garage attics, and exterior walls are the appropriate spots. A fan mounted in the basement or any livable space is a red flag, because piping above a fan is under pressure and a leak there would push radon-laden air indoors.
- Discharge point — Nebraska's radon statute (Neb. Rev. Stat. 76-3504) generally calls for pipe at least 3 inches in diameter terminating at least 12 inches above the roof surface and at least 10 feet from windows or openings that sit less than 2 feet below the exhaust. A pipe that stops at head height next to a patio deserves a question; confirm current requirements with the state rather than assuming.
- Sump lid — if the system draws from the sump pit, the lid should be sealed, with grommets around cords and pipes rather than open cutouts.
- System label — installers typically tag the pipe or fan with a company name and install date. No label means one more question for the seller.
Ask the seller for the paperwork
A well-documented system comes with three pieces of paper: the post-mitigation test result showing the number the system achieved, an installation record naming the installer and the date, and the fan's warranty information. Ask for all three through your agent, the same way you would ask for a furnace service record.
Nebraska generally requires radon mitigation work to be performed by state-licensed professionals, so an installer's name can be checked — confirm current licensing requirements with Nebraska DHHS rather than taking a sticker's word for it. Also ask when the house was last tested. A system proved out once, years ago, and never rechecked is exactly the situation real-estate radon services exist to sort out on a deal timeline.
Test anyway — the number is the proof
None of the checks above replace a measurement. A spinning fan proves suction, not concentration, and the EPA states there is no known safe level of exposure to radon. Order a radon test during the inspection period just as you would for a house with no system, and run it with the system operating exactly as found.
Read the result against the EPA's 4 pCi/L action level, and note that the EPA also recommends considering fixes for results between 2 and 4 pCi/L — the 2-to-4 guide walks through that band. For context, Lancaster County averaged 3.6 pCi/L across the 19,828 measurements in the Nebraska DHHS dataset (county data); a house with a system sits over the same soil as every house without one.
If the check turns something up
A dead fan, a level manometer, a discharge pipe ending under the deck, a missing post-mitigation test — none of these should sink a purchase. They are negotiating items, and mostly modest ones. The usual paths are asking the seller to have the system repaired and retested before closing, or adjusting the price and handling it right after.
Fan replacement and a verification retest are routine work; system repair and retest covers what that involves, and what it costs depends mostly on fan model, mounting location, and whether any piping needs correction — the cost page explains those drivers. If you would rather have the whole assembly looked over before you sign, a radon system inspection in Lincoln can usually be scheduled inside a normal option period.
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Quick Answers
The house already has a radon system. Do I still need a test?
Yes. The system proves equipment was installed; only a measurement shows the current level. Test during the inspection period with the system running as found, and read the result against the EPA's 4 pCi/L action level.
Should the radon fan run all the time?
Yes, continuously. The fan maintains constant suction under the slab, and levels can climb back once that suction stops. If the fan is off or unplugged when you tour the house, ask why and have the system verified before closing.
What paperwork should come with an existing radon system?
Ask for the post-mitigation test result, an installation record with the installer's name and date, and the fan warranty. Nebraska generally requires licensed professionals for mitigation work — confirm current requirements with Nebraska DHHS.