How can I tell if my radon system is working?

Start with the manometer. Uneven fluid usually means the fan is creating suction, but every system is different. A flat reading, changed reading, unusual fan noise, disconnected pipe, loose sump lid, or elevated retest is worth checking.

What photos help American Radon Systems understand an existing system?

Photos of the fan, fan label, manometer, sump lid, exterior pipe, and crawlspace barrier can help Bill understand what you are looking at before he stops out.

Existing System Help

Is My Radon System Working?

If you bought a house with a radon system, or your system has been running for years, it can be hard to know what is normal. Here are the parts homeowners usually ask about and the signs that are worth checking.

Call Bill Now Send Your Info

First Check

Start with the manometer

The clear U-shaped gauge on many radon systems is called a manometer. It shows whether the fan is creating suction in that pipe.

The manometer is not a radon test. The only way to know the radon level in the home is to test the home.

Uneven fluid usually means the fan is pulling. A flat reading, or a reading that has changed from the normal mark on the pipe, is worth checking. Systems vary, so the gauge by itself does not tell the whole story.

Radon system manometer and state license tag on PVC pipe

System Parts

What homeowners usually ask about

Exterior radon fan and disconnect mounted on the side of a home

The radon fan

The fan runs continuously. A quiet hum can be normal. Grinding, rattling, vibration, or silence can mean the fan or the system needs service.

Fan replacement and repair - learn more

White radon mitigation pipe routed through a basement

The pipe

The pipe moves soil gas out of the home. Loose, cracked, disconnected, or oddly routed pipe is worth having Bill look at.

Sealed sump lid with access port for a radon mitigation system

The sump lid

A sealed sump lid helps the system pull from the right place. Access still matters, because the sump pump has to remain serviceable.

Crawlspace plastic

Crawlspace systems rely on sealed plastic and barrier details. Loose seams or torn plastic can affect how well the system pulls.

Outside

The exterior vent

The vent pipe should carry discharge safely outside and above the roofline. If the pipe looks loose, damaged, oddly terminated, or different than it used to, send a photo or call Bill.

If you are trying to understand how a full installation is planned, see what to expect during install.

What photos help Bill

The fan and the fan label, if it is reachable safely.
The manometer on the pipe.
The sump lid or suction point.
The exterior pipe from the fan up to the roofline.
Any crawlspace plastic, loose seams, or torn areas.

When to Call

Signs worth checking

The manometer is flat or the reading changed noticeably.

The fan is loud, grinding, rattling, vibrating, or not running.

A pipe looks disconnected, cracked, loose, or unfinished.

The sump lid is loose or no longer sealed well.

Crawlspace plastic is torn or seams have opened up.

A radon retest came back elevated.

Sources & helpful radon resources

Last reviewed by American Radon Systems: June 2026

CDC reducing radon levels in your home
Explains common radon reduction systems, including vent pipe and fan systems.
U.S. EPA radon overview
Federal radon guidance, including why testing is the way to know a home's level.
Illinois IEMA-OHS Radon Program
Illinois radon program information and licensing context.

Not sure what you are looking at?

Send a few photos or call Bill. We can usually point you in the right direction.