What Happens When Your Backflow Test Fails? A Step-by-Step Guide

You scheduled your annual backflow test like you were supposed to. The tester showed up, hooked up the gauge, ran the test — and your assembly failed. Now what?

First, take a breath. A failed backflow test is not an emergency, and it's more common than you might think. Backflow preventers are mechanical devices with rubber seals, springs, and moving parts. They wear out. It happens. The important thing is what you do next.

At 1-A Services, we test thousands of backflow assemblies across Texas every year, and a percentage of them fail. We walk our customers through the process every time, and we're going to walk you through it right now.

Step 1: Understand Why It Failed

When a backflow assembly fails its annual test, the tester should tell you exactly which component failed and what the readings were. The test report will document the specific failure. Here are the most common reasons:

• First check valve not holding: The first check valve (closest to the supply) didn't maintain the required pressure differential. This usually means the rubber seat disc is worn, scored, or has debris on it.
• Second check valve not holding: Same issue, but on the second check valve. Both checks need to hold independently.
• Relief valve not opening (RPZ): On an RPZ assembly, the relief valve must open at a specific pressure differential. If it doesn't, the fail-safe mechanism isn't working.
• Relief valve not closing (RPZ): The relief valve opens but won't fully close, causing continuous water discharge. This can be caused by debris on the seat or a worn disc.
• Excessive leakage: Some leakage past check valves is measured during testing. If it exceeds the allowable threshold, the assembly fails.

Understanding the failure helps determine whether you need a simple repair or something more involved. A tester who just says "it failed" without explaining the details isn't giving you the full picture.

Step 2: The Failed Test Gets Reported

Here's something that surprises some people: the failed test result still gets filed with your water provider. The tester is required to submit all test results — pass or fail. Your water provider's cross-connection control department will receive the report showing that your assembly did not pass.

This starts the clock. Most water providers give you a specific window — typically 30 to 60 days — to complete repairs and submit a passing retest. The exact timeframe varies by water provider, so check with yours. Some are more lenient than others, but none of them will let a failed test sit indefinitely.

Step 3: Get a Repair Quote

If you're working with 1-A Services, we typically diagnose the issue during the initial test and can give you a repair estimate on the spot or within a day. For most failures, the repair involves replacing internal components — rubber seats, springs, O-rings, and disc assemblies — using a manufacturer's repair kit.

Here's what affects the repair cost:

• Assembly size: A 3/4-inch residential backflow preventer is much cheaper to repair than a 6-inch commercial RPZ.
• Assembly type: RPZ repairs tend to cost more than DCVA repairs because there are more components (the relief valve adds complexity).
• Parts availability: Common brands like Watts, Wilkins (Zurn), and Febco have readily available parts. Older or less common brands may require special-order parts, which adds time and cost.
• Condition of the assembly: If the body is corroded or damaged, a simple rebuild won't cut it. You may need a full replacement.

We always give you an honest assessment. If a $200 repair kit will fix the problem, that's what we recommend. If the assembly is 25 years old and falling apart, we'll tell you that replacement makes more sense than throwing money at repairs.

Step 4: Schedule the Repair

Once you approve the repair, we schedule it as quickly as possible — usually within a few business days, depending on parts availability. For the repair itself:

• We shut off the water to the assembly (this means a temporary water interruption to the line the assembly serves)
• We disassemble the backflow preventer and replace the failed components
• We reassemble the unit and restore water service
• The whole process typically takes 1 to 2 hours, depending on the assembly size and type

We coordinate with you on timing to minimize disruption. If the assembly serves a fire line, we'll work with you to ensure fire protection coverage during the repair (this may involve a fire watch depending on your local requirements).

Step 5: Retest

After the repair is complete, the assembly needs to be retested. This is the same test that was performed initially — a full differential pressure test of all components. If everything checks out, the assembly passes, and we file the passing test report with your water provider.

At 1-A Services, we perform the retest immediately after completing the repair. There's no need to schedule a separate visit — we test it right there, confirm it passes, and file the results. One trip, one invoice, done.

Step 6: Filing and Compliance

Once the passing retest is filed, you're back in compliance. Your water provider will update their records, and you won't hear from them again until your next annual test is due.

We file all test results directly with your water provider on your behalf. You don't need to track down forms, fill out paperwork, or make phone calls. We handle it.

What If the Assembly Can't Be Repaired?

Sometimes a repair isn't feasible. The body might be cracked, severely corroded, or the model might be so old that parts are no longer available. In that case, the assembly needs to be replaced entirely.

A backflow preventer replacement involves:

• Removing the old assembly
• Installing a new assembly of the correct type and size
• Testing the new assembly before it goes into service
• Filing the initial test report with your water provider
• Coordinating any required permits or inspections (some jurisdictions require a plumbing permit for backflow preventer replacement)

Replacement costs more than a repair, obviously, but it also gives you a brand-new assembly with a fresh service life. And you won't be dealing with repeated failures on an aging unit.

What If You Miss the Deadline?

If you don't complete repairs and submit a passing retest within your water provider's required timeframe, they can take enforcement action. This typically starts with warning letters and can escalate to water service disconnection. We've seen properties get their water shut off for non-compliance — it's not common, but it does happen, and it's completely avoidable.

If you're running up against a deadline, call us. We prioritize compliance deadlines and will do everything we can to get you tested and passing before the cutoff.

The Bottom Line

A failed backflow test is a speed bump, not a roadblock. The process is straightforward: diagnose the failure, repair or replace the assembly, retest, and file the results. At 1-A Services, we handle the entire process from start to finish so you can focus on running your property.

If your backflow test just failed — or if it's been a while since your last test and you're worried about what you might find — reach out to us. We're a family-owned company based in Boyd, Texas, and we've been helping property owners across the state stay compliant for years. We'll take good care of you.