The City of Phoenix Planning and Development Department runs the backflow prevention program, and assemblies must be tested when installed, repaired or relocated and at least once a year after that. The test has to be done by a certified tester on the City's list, and the report goes in on a City-approved form. Call the number on this page to be connected with a local plumber in Phoenix who tests and repairs backflow assemblies.
What a backflow assembly protects
Under normal conditions water moves one way: from the City main, into the property, out through the taps. Backflow is that flow reversing. A drop in street pressure can siphon water back out of a building, and a pump or boiler can push water back toward the main. Either way, water from irrigation lines, fire sprinklers, cooling equipment or process lines could reach the public supply. A tested assembly keeps that from happening.
How the Phoenix program works
- Installation: a new assembly is tested when it goes in.
- Repairs and moves: any repair or relocation triggers another test.
- Annual cycle: after that, testing happens at least once a year, usually prompted by a City work order with a due date.
- Who tests: a certified tester on the City's list. The program recognizes ASSE 5000, ASETT or ABPA certification.
- Reporting: an original test report on a City-approved form goes to Planning and Development by the due date, and the customer keeps records for at least three years.
Questions about a notice can go to the City's backflow prevention program at 602-534-2140.
Common assembly types
| Assembly | Where it tends to show up |
|---|---|
| Reduced pressure principle (RP) | Higher-hazard services, many commercial buildings |
| Double check valve | Lower-hazard services and some fire lines |
| Pressure vacuum breaker (PVB) | Irrigation and landscape systems |
When the test fails
A failed test usually traces to debris on a check valve, a worn seat or spring, a leaking relief valve on an RP, or a cracked body. Sun and summer heat are hard on exposed devices, and an unprotected assembly can still crack during an occasional winter freeze. Many testers carry common repair kits, rebuild the assembly, retest it and file the passing report in the same visit. If the body is damaged, the assembly is replaced and tested again as a new install.
Cost factors
Pricing depends on the number and size of assemblies, how easy they are to reach, whether repair parts or a full replacement are needed, and whether several devices on one property can be tested on the same trip.
Backflow Testing questions from Phoenix homeowners
How often do backflow assemblies need testing in Phoenix?
Can any plumber test my backflow assembly?
How long should I keep backflow test reports?
What happens if my assembly fails?
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