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Honest AdvicePublished September 11, 2026 · 4 min read

When You Should Not Hire Us for a Backflow Test

T
Tavish Murray
Owner, TJ Backflow Testing and Repair Services

Tavish Murray owns TJ Backflow Testing and Repair Services in Sanford, FL. Certified backflow tester #7337 and Florida-licensed drinking water (DW #A20193) and wastewater (WW #A16614) operator.

The short version

Do not hire a private backflow tester if your city already tests residential devices under its own program — Longwood, Casselberry and Altamonte Springs all do. Do not hire us to replace a device; that is a licensed plumber's job in Florida. And do not hire us for a fire-line assembly without asking first, because that usually belongs to a fire protection contractor.

We would rather lose a test than take money for something you did not need. Three situations come up often enough that they are worth writing down.

Your city tests it for you

Three Seminole County cities run their own residential testing, and in those cities a private tester on a standard residential device is a duplicate expense.

  • Longwood tests residential devices for $40. Testing only — the city does not repair.
  • Casselberry tests residential irrigation devices every two years through its own contractor, with same-day results.
  • Altamonte Springs tests residential devices at no charge.

If you are in one of those cities and the letter is about a standard residential device, call the number on the letter. Where we are useful in those cities is afterwards: none of the three repair a device that fails, and none of the residential programs cover commercial or multi-device accounts. Those two things are what we do in Longwood, Casselberry and Altamonte Springs.

The device needs replacing, not repairing

Most failed backflow preventers are repairable — worn check discs, tired springs, a fouled seat, a relief valve that will not open. Those are rebuild-kit parts and we fix them in place. But a body that is cracked or corroded through, or an assembly that has been rebuilt before and keeps failing, needs a new device. Installing or replacing a backflow assembly is plumbing contractor work in Florida, and we are not a plumbing contractor.

What we will do is tell you honestly which situation you are in before you spend anything, and once a plumber has installed the new device, test it and file the initial report. What we will not do is sell you a rebuild on a device that will fail again in six months.

One local wrinkle: if someone tells you the fix is a like-for-like replacement of a double check valve, ask first. Casselberry's program page notes that double checks are not approved in Seminole County for that use. The replacement may need to be a different assembly type.

It is a fire line

A backflow assembly on a fire sprinkler service is tested the same way as any other, but the utility tester lists in this region mark fire-line work separately, and in practice it usually runs through a licensed fire protection contractor. If your notice is about the fire line, say so when you call. We will tell you straight whether it is ours to do or point you to who does it, rather than take the job and discover the problem at the filing stage.

When we are the right call

If none of those fit, call anyway and describe it. The answer on the phone is free, and half the time it is "use the city program".

TJ Backflow — we tell you when not to hire us. When you should, the price is quoted before the visit.

FAQ

Which Seminole County cities test backflow devices for residents?

Longwood (testing only, $40, annual), Casselberry (irrigation devices, every two years, through the city's own contractor) and Altamonte Springs (residential devices, no charge). Each publishes the details on its program page.

If the city tests it, why would anyone hire a private tester?

Repairs — none of those three cities repair devices — and commercial or multi-device accounts the residential programs do not cover. Those are the two reasons, and they are the two things we do in those cities.

How do I know if my project is the right fit before calling?

Look at the notice. If it names a city program or a city fee, use the city. If it tells you to hire a certified tester, or says a device failed and needs repair, that is us. If you are not sure, call and we will tell you on the phone — it costs nothing to ask.

Do you charge to come look?

The test price is quoted before the visit and covers the test. If a device fails, the repair is quoted separately before any work starts. There is no separate charge to give you a straight answer on the phone.

Price quoted before the visit

Holding a notice? Call the tester.

Read us the notice. We tell you who it says should do the test, what it costs if that is us, and — if your city already tests for you — that you do not need us at all.