Backflow Testing in Phoenix

A yearly test of every assembly, by a certified tester, filed with the city. City Code 37-143 puts the duty on the customer: test all backflow prevention assemblies at least once a year, submit the results on city forms to the Planning and Development Director, repair or replace anything that fails, and keep the records for three years. Testing follows the USC Manual of Cross-Connection Control, and repairs have to be made by a certified repairer working to ASSE Standard 5130. Phoenix's adopted 2024 code also requires a test at installation and right after any repair or relocation.

The city's rules apply to businesses, apartments, HOAs, schools and other regulated properties. A single-family home used only as a home is outside City Code Article XII unless a cross-connection problem is identified, so most homeowners never get a Phoenix test notice. For what a passing report has to show, see commercial backflow testing and reading a backflow test report.

City Code 37-144 lists it by use, and the list is more specific than most owners expect. Restaurants, supermarkets and butcher shops need an air gap or a reduced pressure (RP) assembly. A retail center, strip mall or shell building where one water service feeds more than one tenant needs an RP. A multi-story building with booster pumps or a rooftop tank needs an air gap, RP or double check. Car washes, nurseries, schools with labs, mobile home and RV parks, and construction water services each have their own entry, and irrigation systems with chemical injection, or with areas higher than the vacuum breaker allows, need an RP. See the full list on our Phoenix backflow facilities page.

This matters at test time. If your building's use has changed since the assembly went in, say a retail suite became a restaurant, the assembly on the wall may no longer be the type the code requires. A passing test does not fix a wrong assembly type, so raise the change of use before the test.

Phoenix is strict about location, because the tester has to reach it. The city's design manual puts the assembly on private property, outside the right-of-way or utility easement. City Code 37-144 says as close as practicable to the point of service delivery, and if a driveway or sidewalk is in the way, the nearest point after the obstacle but never beyond the first tap. RP and double check assemblies may not go in a basement, meter box, pit or vault, and Phoenix's 2024 amendment adds the clearances: at least 12 inches off the ground, a platform above 5 feet, and a 3-foot clear space around secondary assemblies. An assembly buried in a pit or jammed against a wall can fail inspection even when it passes the test.

When a test fails, the usual cause is a fouled check, a torn diaphragm or a worn relief valve, and a repair kit puts it back in service, followed by a retest. See backflow assembly repair and replacement.

Replacement is where Phoenix's own documents conflict. City Code 37-143 says "The customer shall obtain a permit from the Planning and Development Department for the installation of any backflow prevention assembly." The city's backflow location guideline, TRT 00634 (Rev. 7/25), Section B1, says installation, alteration or replacement of all backflow prevention assemblies requires a plumbing permit. But the 2024 PBCC, Section 105.2 Plumbing item 6 (Ord. G-7397, in force since August 1, 2025), exempts repair or replacement of existing 2 inch and smaller secondary assemblies, as long as a test report by a certified tester is submitted to the city. No Phoenix text reconciles them.

The conflict covers one slice only: replacing an existing secondary assembly 2 inches or smaller. A primary assembly, anything over 2 inches, a new install or a relocation needs a permit under every one of these documents. If your swap falls in that slice, call Planning and Development at 602-262-7811 and ask which rule they apply before the old assembly comes out.

Phoenix requires the initial and annual test on a fire line or fire sprinkler assembly to be done by a certified tester who is also permitted by the City Fire Marshal, with a full flow test. Fire line and fire sprinkler backflow work is outside what HQ does, so that assembly goes to your fire protection contractor. We handle the domestic water assemblies on the same property.

If the assembly was stolen or the meter is locked off, there is nothing to test; see stolen backflow assembly replacement. If water is pouring from the relief port, that is a repair call first; see an RPZ spitting water. And if your notice is for a single-family home, ask the city why before you book a test.

City Code 37-146 lets the Director add a civil penalty of up to 1,000 percent of water charges per billing period until the work is done, and shut off water on ten days' written notice, or immediately if the system is a health hazard. Restoring service also means paying the city's costs. So book the test when the notice arrives. See missed backflow test deadline in Phoenix.

Send us the city notice or the assembly's size, make and location. We test, repair and replace domestic assemblies, and we file the report with the city. We give an upfront price before work starts and free estimates on replacements. For restaurants, see restaurant backflow testing; for the rest of our Phoenix work, the Phoenix service area page.