Becoming a backflow tester follows one sequence: build documented field experience, complete a backflow tester training course, pass the written and practical exams, set yourself up with the program that requires the tests, then go find the work.
Under ASSE 5110, the national reference credential, that means five years of documented, related field experience, a 40-hour course and two exams — though your jurisdiction may run its own scheme with different rules.
Prerequisites for becoming a backflow tester
The entry gate depends on which credential you pursue, and which credential counts is decided where you work.
Under ASSE 5110 — the national reference — eligibility requires at least five years of documented, related field experience, a 40-hour training course, a written exam and a hands-on practical.
Start (or keep) documenting that experience now: documented is doing real work in that sentence, and reconstructing five years of work history after the fact is the slow way round.
The five-year rule is ASSE's, though — not a national gate.
Many jurisdictions run their own tester certification with their own entry rules, and our research found state-issued tester credentials in Texas, Arkansas, Virginia, Wisconsin, Minnesota and Washington.
Texas shows how different a state path can read: its TCEQ Backflow Prevention Assembly Tester (BPAT) licence is required of anyone who tests or repairs backflow prevention assemblies in the state, and it asks for a high school diploma or GED, two years of approved experience — plumbing, water-system operation, irrigation and fire-sprinkler work are among the examples TCEQ lists — and a TCEQ-approved 40-hour course.
Where the credential rides on the plumber licence, you start as a plumber.
Louisiana's Water Supply Protection Specialist backflow endorsement is available to licensed journeyman or master plumbers — or licensed landscape irrigators — who complete a 40-hour tester certification.
If that's your route, the plumbing license requirements come first, and the backflow credential layers on afterward.
- Ask the water purveyor or state program you'd test under which credential it accepts
- Start documenting your related field experience — ASSE 5110 asks for at least five years
- Check whether your state issues its own tester licence or accepts a national certificate
Entry rules are local — verify before you enroll
The 40-hour backflow tester training course
The course is the fixed part of the ASSE sequence: 40 hours of training, taught at ASSE-approved schools.
It is classroom-plus-hands-on by design.
The USC Foundation for Cross-Connection Control and Hydraulic Research (FCCCHR), one of the national institutions in this field, runs a Tester Training Course that pairs a series of lectures with guided exercises in a wet lab — and that mix matters, because the exam you're heading toward includes a hands-on practical, not just a written test.
What a backflow certification class actually covers, what it costs and where to find one is its own topic: our backflow certification class guide breaks down course hours, test-kit practice, cost and enrollment.
Pick a course your program accepts — an approved-but-unaccepted certificate buys you nothing.
The exam: written test and hands-on practical
Two exams close out the ASSE route: a written exam and a hands-on practical, with the practical covering the four assembly types abbreviated RP, DC, PVB and SVB.
Pass both and the certification is yours.
The exam detail — format, scoring and what the practical expects you to demonstrate — is covered step by step in our backflow tester certification guide.
Certification isn't one-and-done, either.
ASSE certifications, 5110 included, must be renewed every three years, and recertification is a real checkpoint: at least an 8-hour class plus a written exam — 50 questions today, rising to 100 from January 1, 2027 — and a hands-on practical exam.
Build that cycle into your plans from day one; it's the recurring cost of keeping the credential.
Registering with water purveyors
Passing the exam earns you the certificate — it doesn't automatically earn you a place on the list of testers a program accepts.
Backflow testing exists because water suppliers have to protect the public grid, and the program that requires each test — usually the local water purveyor or code authority — decides who may submit results and under which credential.
Some jurisdictions keep their own tester lists; others name the credentials they accept; in states like Texas, the credential is the state's own licence.
So make that program your first call, before you enroll in anything: ask which tester certification it accepts, how it wants testers registered, and how results get filed.
The registration mechanics — which programs run their own lists and which credentials each state names — are covered in detail in our guide to getting certified.
Getting your first backflow testing work
Most testers arrive from the pipe trades, and for a working plumber the straightforward first book of testing work is the employer they already have: ask whether backflow testing is a service line your shop wants to add.
Louisiana's endorsement route — licensed journeyman or master plumbers adding the backflow credential to the licence they hold — shows how naturally the testing work sits inside a plumbing business.
Fire-sprinkler contractors are their own seat in the field, too: ASSE certifies fire-sprinkler cross-connection testers separately, as 5140.
Water purveyors and the cross-connection control programs they run sit at the center of the field, since they're the programs the test results feed.
The economics also favor repetition.
Assemblies are tested on a schedule the local program sets — annual testing is a common local rule, though our research did not confirm it from a primary source, so treat your purveyor or local code as the authority.
A recurring list of properties to retest is what makes route-based testing work possible once you're established.
When you're ready to job-hunt, the backflow tester jobs on HVACHires are where that credential goes to work.
For the field as a whole, the backflow tester career guide covers what the work involves and who hires, and the backflow tester salary page has the national and state pay tables.
Career information, not legal advice — certification and testing requirements are set by your water purveyor, state program or licensing board. Confirm the current rules with the authority in your jurisdiction before you act on them.