| Quick facts | Answer |
|---|---|
| Cost range | Commercial 3/4"-1.5" tests listed around $125 in the Charleston area |
| Time | Certification is a 4-day course; the test itself is quick |
| Who's qualified | A tester holding a current DES Tester Certification Certificate, renewed every 3 years |
Why DIY fire sprinkler backflow testing is illegal in Charleston
South Carolina DES says all backflow testing must be done by a state-certified backflow prevention tester. The Fire Protection Sprinkler Systems Act also requires a current Tester Certification Certificate from the Department of Environmental Services. Without that card, you cannot legally test your own fire line.
What a Charleston pro checks on a fire sprinkler backflow test
The test must follow applicable NFPA standards. South Carolina requires fire line sprinkler systems to be protected by at least an approved double check valve assembly. If antifreeze, foaming agents, or an auxiliary water supply is tied into the fire line, a reduced pressure backflow assembly is required instead.
When to call a pro for your fire sprinkler backflow test
Call a pro for every test - it is not legal to do it yourself without certification. Repairs found during the test must also be made by a DES-certified backflow prevention assembly tester. Ask the pro for proof of licence, insurance, and a current certification card.
How to become a certified backflow tester in South Carolina
Certification requires a 4-day course, then a proctored practical exam and a written exam. Certification must be renewed every 3 years by exam. DES lists a Charleston training class at the North Charleston Convention Center, with dates shown as June 9-12, 2026.
What to do next
- Schedule a fire sprinkler backflow test that follows the applicable NFPA standards.
- Ask the tester to show a current DES Tester Certification Certificate before work starts.
- Confirm your fire line has at least an approved double check valve assembly, or a reduced pressure assembly if antifreeze or an auxiliary supply is connected.
- Get repair pricing in the quote, since repairs must be done by a DES-certified tester.
- Call (843) 286-4721 or email [email protected] for a free quote from a licensed, insured local backflow tester.
CHS Backflow is a free referral service: an independent contractor does the work and may pay us a referral fee. You never pay us anything.
