Should I Have a Radon Test Performed Even if There’s an Active System Present?

 Yes—absolutely still test for radon during your home inspection, even if there’s already an active mitigation system installed. 

Why a radon test matters: 

Systems can fail or underperform 

An active radon mitigation system is designed to reduce radon levels, but it’s not a guarantee. Various factors, such as an improperly sized radon fan, fans that are not operating at capacity, interior radon pipes, and sump pumps, can leak, as can potential underlying issues with the home that can interfere with the system. Perhaps the existing radon system was not properly designed for the home. 

You need to verify current levels 

The only way to know if the home is actually under the radon action level is to measure it. Radon levels are measured in pCi/L, and the Illinois Emergency Management Agency recommends action if levels exceed 4.0 pCi/L. 

It can affect negotiations 

If the test shows elevated radon despite the system, you may be able to: 

• Request repairs or upgrades 
• Ask for a credit 
• Renegotiate terms 

It establishes a baseline for you 

Even if levels are low, you’ll have documentation that the system is working properly at the time of purchase, which is useful for future monitoring. 

What to do during a home inspection 

• Request a short-term radon test (usually 48 hours) 
• Ensure it’s conducted under proper “closed-house conditions.” 

The bottom line 

A mitigation system is a good start—but it’s not proof that it is actually doing the job well. Testing is quick, relatively inexpensive, and gives you real protection, leverage, and overall peace of mind. 

Choose Guardian Radon for all Your Radon Mitigation Needs

While Guardian Radon Mitigation doesn’t provide testing services, we can steer you in the right direction when it comes to radon mitigation and keeping your home’s air quality safe. Our trucks are always out and about in the western Chicagoland suburbs, including Plainfield, Oswego, Naperville, Aurora, Yorkville, servicing homes and keeping radon mitigation systems running. If you have any radon mitigation questions, give us a call at (630) 768-9836 or contact us here.