Annual Backflow Testing Checklist — Stay Compliant and Protected

Most jurisdictions send a reminder letter 60–90 days before your annual test is due. If you haven't received one, call your water provider — your contact information may be outdated. Common deadlines are the anniversary of installation or a fixed calendar date (often April–June). Some cities shut off water service for non-compliance with zero warning after the deadline passes.

Most residential properties have one backflow preventer at the water meter or near the main shut-off. Properties with irrigation systems, fire sprinkler systems, pools with auto-fill, or boiler systems may have multiple devices — each requiring individual testing. Your water utility maintains a registry of devices on your property. Request a copy to ensure nothing is missed.

Walk the property and identify each device. Common locations: near the water meter (above-ground or in a vault), on irrigation supply lines (often in a valve box in the yard), on fire sprinkler connections (usually in the mechanical room), and on commercial kitchen supply lines. Note the type (RPZ, double check, PVB) and tag number for each. If you can't find a device, a plumber can trace the lines.

Certified backflow testers are in high demand during testing season (spring). Scheduling 30–45 days ahead ensures you get your preferred date. The tester must hold a current backflow testing certification in your jurisdiction — ask for their certification number. Many plumbing companies have certified testers on staff; you can also find certified testers through your water utility's approved list. Cost: $75–$200 per device for testing.

Testers need physical access to the device for 15–30 minutes per device. Underground devices in valve boxes need the lid removed. Devices behind locked fences need the gate unlocked or the key available. Overgrown vegetation hiding the device needs to be trimmed back. If the tester can't access the device, they charge a return visit fee ($50–$100) and you lose your time slot.

Backflow testing requires closing valves upstream and downstream of the device for 5–15 minutes. During this time, water service to the property (or to the specific circuit — irrigation, fire, etc.) is interrupted. Plan accordingly: don't schedule during laundry cycles, don't run the dishwasher, and notify occupants. The interruption is brief but total.

The tester needs to close the gate valves or ball valves on each side of the backflow device to isolate it. If these valves are seized, corroded, or broken, the test can't be performed until they're repaired — adding a separate plumbing call and delaying your compliance. Cycle each valve fully closed and open once before test day. If a valve won't move, schedule a plumber to repair or replace it before the tester arrives.

A backflow test kit measures pressure differential across each check valve and the relief valve (on RPZ devices) to verify they open, close, and hold at the correct pressures. The tester connects hoses to small test cock fittings on the device. This is a non-destructive, non-invasive test — nothing is disassembled unless the device fails.

If the device fails the test, the tester will explain what's wrong and whether a field repair (O-ring, spring, check seat replacement) can fix it immediately or if the device needs a full rebuild or replacement. Being present lets you authorize the repair on the spot rather than scheduling a second visit. Most field repairs cost $50–$200 in parts and 15–30 minutes additional labor.

The tester fills out a standardized test report form with device serial number, type, test results (pass/fail with pressure readings), and their certification information. This report must be submitted to your water utility — the tester typically handles submission, but confirm they will do so and ask for a copy for your records. Without the submitted report, your test doesn't count regardless of whether the device passed.

Common failure causes — worn rubber check seats, weak springs, debris in the valve — can be repaired in the field in 15–45 minutes using a rebuild kit ($30–$100 in parts depending on device size). The tester re-tests immediately after repair. This is the fastest and cheapest resolution. Most certified testers carry common rebuild kits in their truck.

Severely corroded, cracked, or obsolete devices may not be repairable. Replacement with a new device of the same type costs $200–$800 for the device plus $150–$400 for installation, depending on size and type. Your municipality typically allows 14–30 days for replacement and re-testing. Don't let this deadline pass — fines accumulate daily in some jurisdictions.

After repair or replacement, the device must be re-tested and a passing report submitted to the water utility. Don't assume the repair automatically closes the compliance loop — a new passing test report is required. Many testers offer reduced re-test fees ($50–$75) if the re-test is within 30 days of the initial failed test.

Keep copies of all backflow test reports for at least 3 years. You may need them for property sales (buyer due diligence), insurance claims, or disputes with the water utility about compliance history. A folder in your filing cabinet or a scanned digital copy works — just don't rely solely on the utility having your records on file.

Walk by the device quarterly and check for water pooling around it (leaking check valve or relief valve), visible corrosion on the body or fittings, physical damage from lawn equipment or vehicles, and insect nests in relief valve discharge ports. Catching a small leak early prevents a failed annual test and the associated repair costs.

Above-ground backflow preventers (RPZ assemblies, PVBs) are vulnerable to freeze damage. A frozen RPZ can crack the bronze body — a $400–$800 replacement. Insulated covers ($30–$80) protect down to about 20°F. For colder climates, some property owners drain and shut down irrigation backflow devices seasonally. Your certified tester or plumber can advise on the right winterization approach for your climate and device type.