Backflow testing costs about $75 to $250 per device in 2026
An annual backflow test costs about $75 to $250 per device for most homes in 2026. The average is about $143. Most homes have one device. If the test fails, repairs add labor and parts, and the device must be tested again.
What backflow testing costs
| Home test, per device | $75 to $250 |
|---|---|
| Average test | About $143 |
| One Washington tester, per device | From $73 |
| Business test, per device | $150 to $400+ |
| Repair labor if it fails | $50 to $150 plus parts |
| Retest after repairs | $25 to $75 |
| Below ground vault surcharge | $50 to $100 |
| New backflow preventer, installed | $150 to $450 |
The price usually covers the visit, the test and sending the report to your water company. Repairs are billed on top. Sources: FindBackflowTesters.com, backflow assembly testing cost guide (April 2026); HomeYou, average cost of backflow testing in 2026 (April 2026); Backflows Northwest, prices (checked September 2026); HomeAdvisor, backflow preventer cost (June 2026).
What changes your price
- How many devices. Most homes have one. Businesses often have 2 or 3.
- The device type. Bigger and more complex devices take longer to test.
- Access. Devices in underground vaults cost more to reach.
- A failed test. Repairs and a retest add to the bill.
- Your city. Big cities like Los Angeles, Chicago and New York cost more.
- City report fees. Some cities charge to file the test report.
Why you get the test every year
A backflow preventer stops dirty water from flowing back into your clean water. Many water companies require a test every year and mail a reminder with a 30 to 90 day window, says FindBackflowTesters.com. The tester hooks a gauge to the device, runs the test and files the report.
If the device fails, the costs add up. FindBackflowTesters.com puts repair labor at $50 to $150 plus parts. A rebuild kit for a common home valve runs $30 to $80. After the repair, the device must be tested again, which some testers include and others bill at $25 to $75.
Prices vary by tester. Backflows Northwest in Washington lists a home test from $73 per device. HomeYou puts the national average at about $143, with most tests between $89 and $218.
Big cost guides land in the same place. Angi puts a typical test at $70 to $90, and HomeAdvisor at $70 to $350 a year, with a permit of about $50 for a new device. HomeGuide says most homes have one device, while businesses often have 2 or 3, and a new device can cost $200 to $1,000 installed. Sources: FindBackflowTesters.com, backflow assembly testing cost guide (April 2026); Backflows Northwest, prices (checked September 2026); HomeYou, average cost of backflow testing in 2026 (April 2026); Angi, backflow preventer installation cost (September 2026); HomeAdvisor, backflow preventer cost (June 2026); HomeGuide, backflow testing cost (September 2024).
Backflow testing and your sprinklers
Many homes need a backflow test because of the lawn sprinkler line. If the test turns up a leak or broken part, see our sprinkler repair page. A new backflow preventer is the most expensive sprinkler repair.
If the device sits on your main water line, a plumber may do the fix. Our plumber hourly rate page shows what they charge.
How to judge the price you are quoted
- Ask if filing the report with your water company is included.
- Ask what a repair and a retest will cost if it fails.
- Check that the tester is certified in your area.
- Ask if there is a trip fee.
- Compare with $75 to $250 per device.
Ways to pay less
- Book early in your testing window. Rush jobs can cost more.
- Ask your neighbors to book the same tester on the same day.
- Pick a tester that includes one free retest after repairs.
- Protect the device from freezing so it does not crack.
- Book the test with your sprinkler start up if the device is on your sprinkler line.
How we got these numbers
Testers set their own prices. The ranges come from 2026 testing guides, one tester price list and cost guides, as dated below. We do not add our own guesses. All numbers were checked on September 28, 2026.
Common questions
How much does backflow testing cost?
About $75 to $250 per device in 2026 for a home. The average is about $143.
How often is backflow testing required?
Most water companies require it once a year.
What happens if my backflow test fails?
The device must be repaired, often $50 to $150 plus parts, and then tested again.
How much does a new backflow preventer cost?
About $150 to $450 installed for most homes.