Passive radon system activation
If your home has a radon pipe with no fan on it, adding the fan is called activation. Activation starts at $900. Call for details.
Test first
Start with a county kit if you don't have a result yet. Cook County has a free kit, and Will County sells one for $8. The steps are on the radon testing page.
The EPA action level is 4.0 pCi/L. EPA says to fix a home at that level or higher, and to consider a fix between 2 and 4 pCi/L.
Homes built in Illinois after June 1, 2013
Since then, the Radon Resistant Construction Act (420 ILCS 52) has required a passive radon pipe in new Illinois homes.
Many newer homes around New Lenox, Manhattan, Frankfort, Shorewood, and Homer Glen have the builder's pipe and still test high. The builder did what the law asked. A passive pipe moves some radon on its own, but in plenty of homes it isn't enough.
When the pipe is there and in good shape, adding a fan is the simplest fix and the smallest job we do. We don't drill a new suction point or run new pipe through finished rooms. The fan goes on the pipe you have, we check the gauge to make sure it's pulling, and you test again. Section 25 of that law says only a licensed radon contractor may add the fan.
How to spot the pipe
- A white PVC pipe with a cap, in the utility room, garage, a closet, or the attic. It runs up through the home and out the roof. It is not a bathroom vent or the water heater vent.
- A label on the pipe. EPA's construction page says the pipe should be 3-inch or 4-inch PVC and labeled "Radon System." Builders often write "radon" or "radon vent" instead. The EPA bulletin says to label the pipe on each floor so it is not mistaken for a sewer line.
- An outlet in the attic next to the pipe. The same bulletin says to leave one there for a fan later.
- No fan on the pipe, and no humming. A running fan is usually easy to hear in the attic or outside.
If you are not sure, text a photo of the pipe and its label to (815) 370-9682, and Bill will tell you what it is. There's no charge for that.
Bill checks the pipe first
- Where the pipe starts, and whether it seems connected to the area under the floor.
- Whether the pipe route and the spot where it ends outside will work with a fan.
- Whether your basement, crawl space, slab, or a mix of them needs a different approach.
- Whether using the passive pipe is cleaner than building a separate system.
Where these rules come from
Last reviewed by American Radon Systems: October 29, 2026
- Radon Resistant Construction Act (420 ILCS 52), Illinois General Assembly
Cited for the passive-pipe requirement and for who may add the fan.
- EPA, radon action level
Cited for the action level in the test section.
- EPA 402/B-20/007, Activating a Passive Radon System
Cited for the floor label and the attic outlet.
- EPA, Radon-Resistant Construction Basics and Techniques
Cited for the pipe size and the Radon System label.
- Illinois Emergency Management Agency, Radon Program
State radon program, licensing, and public guidance.
Call about the pipe
Call Bill or fill in your info. There's no trip charge for him to come look.
Passive system questions
Pipes with no fan, what changes once the fan goes in, and the warranty.
Can a newer home still have high radon?
Yes. Radon comes from the soil, not the age of the house. Newer Illinois homes often have passive radon piping by law, but that pipe does not always keep the level down until a fan is added when testing shows it is needed.
Does the radon fan run all the time?
Yes. A healthy mitigation fan runs continuously, and it should not be switched off in winter or while you are away. Whenever it is off, soil gas has its normal path back into the house, and the system gives no protection until it is running again. In our experience, running it year-round adds roughly $60 to $125 a year to the electric bill, depending on the fan and your rate. A light steady hum can be normal. If it gets loud, rattles, or goes silent, call Bill; that is a service call, not a switch.
What is your warranty?
If a fan we installed fails during its first five years, the visit, labor, and replacement fan are covered.
Read the customer-care warranty details.Why does my newer home have a radon pipe but no fan?
That is usually a passive radon system: rough-in piping that Illinois has required in new residential construction since June 1, 2013, under the Radon Resistant Construction Act. It is not the same as a completed active system. If a test is elevated, activation adds the right fan and finishes the system so it pulls correctly. Bill checks whether the existing pipe is usable first.