Installing a radon system is only half the job. A retest tells you whether it actually lowered the level in your home. We connect York homeowners with a local contractor who explains when to test, where to place the kit, and what to do if the result is not where it should be.
When to Retest
Give the system time to reach a steady state before you test. Many guides suggest waiting at least a full day after the fan starts. Testing within the first month after install is common, so you get an answer while the work is fresh and any adjustments are easy to arrange.
If you are selling or buying a home, the timing may be set by the sale. Let the contractor know your closing date so the install and retest fit inside it.
After the first retest, plan to test again every couple of years. Test again after major changes to the house, such as finishing the basement, replacing the furnace, or adding a room, since those can change how air moves through the home.
Placing the Test Kit Correctly
Where you put the kit matters as much as when. Place it in the lowest level of the home that is used as living space, such as a finished basement family room or a first floor bedroom if there is no basement living area.
Set the kit about two to six feet off the floor, away from exterior walls, windows, and vents, and out of drafts. Do not place it in a kitchen, bathroom, or laundry room, where humidity and fans can affect the reading.
Keep windows and doors closed for at least twelve hours before the test and during it, except for normal coming and going. Run the heat or air conditioning as you normally would. Follow the kit directions for how long to leave it, then send it to the lab promptly.
Reading the Result and Next Steps
A good result will be well below the 4 pCi/L action level, and many systems bring levels much lower than that. Keep a copy of the lab report with your home records.
If the result is still high, do not panic. The contractor can check the manometer, look for leaks at pipe joints or slab openings, and confirm the fan is running at full strength. Sometimes an unsealed sump, a floor drain, or a crack hidden behind stored boxes is letting air bypass the system. In other homes, a second suction point is the answer.
Ask the contractor to explain what they find in writing, so you know what changed and why. Small details like these separate a system that works on paper from one that works in your house.
Confirm Your System Is Working
A retest is the proof that your radon system is doing its job. Knowing the steps ahead of time takes much of the stress out of the process. With the right information, the next step is usually simpler than it first seems. Every home is a little different, and a short visit is the fastest way to learn what yours needs. Call us and we will connect you with a local contractor who can explain retest timing and placement for your York home, and help sort out the next step if the number is not where you want it.
Frequently Asked Questions
How soon after mitigation should we retest?
Many guides suggest waiting at least a full day after the fan starts, then testing within about the first month. That gives the system time to settle while any adjustments are still easy to arrange. If you are on a home sale timeline, plan the retest window with the contractor when you schedule the install.
Where should post-mitigation test kits be placed?
Place the kit in the lowest lived in level, two to six feet off the floor, away from exterior walls, windows, vents, and drafts. Avoid kitchens, bathrooms, and laundry rooms. Keep windows and doors closed for at least twelve hours before and during the test.
What if the retest is still above the action level?
Call the contractor. They will check the gauge, look for leaks at pipe joints and slab openings, and confirm the fan is working. Unsealed sumps, drains, or hidden cracks are common causes. Some homes need a second suction point. The fix should be explained in writing before any added work.