Retest the home to confirm radon remains low
A running fan or normal-looking indicator does not itself show the radon level inside the home.
When it usually needs attention
Usually repeats every 2 years
EPA recommends retesting at least every two years to confirm levels remain low.
When this guide applies
Only applies when a radon-reduction system is confirmed.
What to do
Use an EPA-recognized test route or qualified radon measurement professional, follow the test instructions exactly, and keep the dated result with the system record.
Applies when: Only applies when a radon-reduction system is confirmed.
Who should handle it: The responsible owner arranges required testing and mitigation; renters or shared-building residents report results and follow the property or local authority process.
Tools
- EPA-recognized radon test or qualified measurement provider
- Prior result and mitigation record
Parts and supplies
- Test materials specified by the selected approved method
Safety gear
- None for placing an approved consumer test in a safe occupied area
Before you start
- Follow closed-house and placement instructions exactly
- Record weather or unusual building conditions requested by the method
Power, water, or fuel shutoffs
- Keep the mitigation system operating as the test instructions require
Cleaner or chemical limits
No cleaner or household chemical is part of radon testing.
Stop and get help when
- Do not place a test in an unsafe or inaccessible area
- Do not interpret a concerning result as permission to adjust the system yourself
Who to call: Use the state radon program or a qualified radon measurement and mitigation professional for concerning, inconsistent, or uncertain results.
Reviewed sources
- Maintaining a Radon Mitigation SystemU.S. Environmental Protection Agency · reviewed July 13, 2026