Selling a house with a working radon mitigation system should be a selling point, not a snag. It becomes a snag fast when nobody can find the warranty paperwork or agree on whether it transfers to the buyer at closing.
- Get the radon mitigation warranty transfer in writing before closing. Verbal promises from the installer don’t survive a sale.
- Systems installed by Michigan Radon Control carry a 5-year warranty that can transfer to a new owner with a written request.
- Ask for the original NRPP certification number and permit before you negotiate anything with a buyer.
- A non-transferable warranty is leverage for the buyer to negotiate credit, not an automatic dealbreaker.
- Retest radon levels before the warranty transfer request goes out to confirm the system still holds below the EPA action level of 4 pCi/L.
Why this matters
Michigan requires sellers to disclose known radon test results and any mitigation system on the property, and buyers increasingly ask their agents to confirm whether that system's warranty follows the house. Sellers who show up to closing with no transfer paperwork lose negotiating ground because buyers assume the worst and price it into their offer. Reviewing Michigan's radon disclosure requirements when selling before you list tells you exactly what documentation you're legally expected to produce, and warranty status is usually part of that conversation.
A transferable warranty also changes the buyer's math. If a fan failure or a cracked pipe seal is covered for the next few years, the buyer has one less reason to renegotiate price after inspection. In 2026, with radon disclosure scrutiny higher than it was five years ago, a documented, transferable warranty is closer to a closing tool than a formality.
What you'll need
- The original installation contract from the mitigation company, including the system type and install date
- The warranty document itself, specifically the section on transferability and any conditions attached to it
- Contact information for the original installing contractor
- Your most recent post-mitigation radon test result, ideally from within the past 12 months
- Photos or a reading of the system's U-tube manometer showing the fan is under vacuum
- Your buyer's agent or attorney's contact info for attaching the transfer to the purchase agreement
If any of this is missing, start pulling it together before you list, not after an offer lands. Buyers' inspectors ask for this paperwork specifically, and scrambling for it mid-negotiation weakens your position.
The steps
1. Locate the warranty and read the transfer clause first
Most radon mitigation warranties are not automatically transferable. They require a written notice, sometimes within a set window after closing, sometimes with a small administrative fee. Read the exact language before you tell a buyer anything. Warranties written for the original homeowner only, with no mention of assignment, need direct contractor confirmation before you can promise a buyer anything in writing. Skipping this step is the single most common mistake sellers make, because they assume warranty means it just follows the house.
2. Call the installing contractor before you list
Contractors handle transfer requests differently. Some process them free within 30 days of a sale, others charge a re-inspection fee to reissue coverage under a new name. Call and ask directly: is this warranty transferable, is there a fee, and what documentation does the new owner need to submit. Get the answer in an email so you have it in writing to show your buyer's agent later. This single call, done two or three weeks before listing, prevents almost every warranty dispute that shows up at closing.
3. Order a system verification before you negotiate anything
A warranty transfer is worthless to a buyer if the system isn't actually working. Before you put a transfer offer on the table, confirm the fan is running, the manometer reads correctly, and radon levels are still under 4 pCi/L. Verifying that your radon mitigation system is still working takes an inspector under an hour and gives you a current reading to hand the buyer alongside the warranty paperwork. A stale 2019 test result does nothing for your negotiating position in 2026.
4. Draft the written transfer request
Once the contractor confirms transferability, submit the request in writing: name of the new owner, closing date, property address, and system serial or install number if one exists. Attach the current test result from step three. Most contractors turn a clean, complete request around within a week; incomplete requests sit in a queue.
5. Negotiate the fee, not the warranty itself
If the contractor charges a transfer fee, that's negotiable between buyer and seller, not a reason to abandon the transfer. A $75 to $150 fee split at closing is a normal ask and far cheaper than a buyer demanding a price reduction over warranty uncertainty. Put the fee and who pays it directly into the purchase agreement addendum.
6. Attach the transfer confirmation to the purchase agreement
Don't let the warranty transfer live in a side email thread. Add the confirmation letter or transfer certificate as an exhibit to the purchase agreement so it's part of the closing file. Title companies and buyer's attorneys expect documentation, not a verbal assurance from the seller.
Selling soon? Confirm your warranty status
Get a system check and transfer paperwork sorted before you list.
7. Confirm the new owner is registered with the contractor
After closing, follow up once to confirm the buyer's name is on file with the mitigation company as the warranty holder of record. This closes the loop and protects you from being contacted years later about a system you no longer own.
Troubleshooting
The warranty already expired. Negotiate a credit for a new one-year service warranty instead of promising coverage that no longer exists. Don't imply transfer on a lapsed policy.
The original contractor is out of business. A new company can often issue a fresh warranty after an inspection, which resets coverage and gives the buyer something current rather than a dead paperwork trail.
No paperwork exists at all. Order a full system inspection and radon retest, then have the new inspecting company issue documentation the buyer can rely on going forward. This substitutes for a missing original warranty.
The buyer's inspector flags a reading above 4 pCi/L despite the system. This usually means fan failure, a disconnected suction pipe, or a sealing gap, not a design flaw. Negotiating radon mitigation costs during a home purchase covers how buyers and sellers typically split repair costs when this comes up mid-transaction.
The contractor's transfer fee feels high. Get a second contractor's quote to re-warranty the system independently. Sometimes it's cheaper than the original installer's transfer fee, and either route gives the buyer coverage.
The buyer wants longer coverage than what transfers. An extended service plan purchased at closing, paid by either party as a negotiated concession, is a normal add-on separate from the original installation warranty.
Tools and resources
- Original installation contract and warranty document
- A current post-mitigation radon test, ideally run within the last 12 months
- Written confirmation from the installing contractor on transfer terms and fees
- A closing addendum template from your agent or attorney naming the transfer explicitly
What to do next
If you haven't listed yet, work through warranty transfer questions before your first showing, not after an accepted offer. Preparing a radon mitigation system before listing walks through the pre-listing checklist, including warranty status, alongside testing and disclosure steps so nothing surfaces late in your transaction.
FAQ
Does a radon mitigation warranty automatically transfer when you sell a home?
No, most radon mitigation warranties require a written transfer request to the original contractor, not an automatic transfer at closing. Read the transfer clause in your warranty document and contact the installer before listing to confirm the process and any fees.
Who pays the radon mitigation warranty transfer fee when selling a home?
The fee, often $75 to $150, is negotiable between buyer and seller and should be written into the purchase agreement addendum. Many sellers split it or absorb it as a small closing concession to keep the deal moving.
What happens if the radon mitigation warranty already expired before I sell?
An expired warranty cannot be transferred, but you can negotiate a credit toward a new service warranty or have a contractor inspect and reissue coverage after a system check. Don’t tell a buyer a lapsed warranty is active.
Can a new radon mitigation warranty be issued if the original installer is out of business?
Yes, a different NRPP-certified contractor can inspect the system and issue a new warranty after confirming it meets EPA performance standards. This is common when the original installer has closed or changed ownership.
How do I prove a radon mitigation system still works before a warranty transfer?
A current radon retest showing results below the EPA action level of 4 pCi/L, combined with a manometer reading confirming fan suction, proves the system is functioning. Order this before submitting a transfer request so the paperwork reflects current performance, not an old reading.
Is a radon mitigation warranty transfer required by Michigan real estate law?
Michigan does not legally require a warranty transfer, but sellers must disclose known radon test results and any installed mitigation system. A documented transfer strengthens your disclosure file and reduces buyer pushback during inspection negotiations.
How long does a radon mitigation warranty transfer take to process?
A complete, written transfer request with current test results typically processes within a week when the paperwork is clean. Incomplete requests, or ones missing a current radon retest, take longer because contractors send them back for more information.
What warranty length is standard for a radon mitigation system installed in Michigan?
Systems installed by Michigan Radon Control carry a 5-year warranty on parts and workmanship, which can transfer to a new homeowner with a written request. Warranty lengths vary by contractor, so always check the original document for your specific system.
One last thing
Most sellers only think about the warranty transfer after an inspector flags the system during a buyer's due diligence period. By then you're negotiating from a defensive position instead of a documented one. Handle the transfer request and a fresh radon retest before you list in 2026, and the warranty becomes something your listing agent points to, not something your buyer's attorney has to chase down.
Related guides
- Best radon mitigation warranties in Michigan
- Radon mitigation for home sellers before listing
- How to negotiate radon mitigation costs during a home purchase