How to Read Your Backflow Test Report
Backflow test reports are full of numbers and abbreviations that can be confusing. Here's a plain-English guide to understanding what your report actually says.
You just had your backflow preventer tested, and now you're looking at a report full of numbers, abbreviations, and checkboxes. If you're not a plumber or a backflow tester, it probably looks like a foreign language. Don't worry — you're not alone. Most property owners have no idea what their backflow test report means, and honestly, most testers don't take the time to explain it.
We're 1-A Services, and we believe you should understand what you're paying for. So let's break down a typical backflow test report, section by section, in plain English.
What Is a Backflow Test Report?
A backflow test report is the official document that records the results of your annual backflow preventer test. It's completed by a licensed backflow tester (like us) and submitted to your city's water utility as proof that your device is working properly. The report follows a standardized format, though the exact layout varies slightly depending on the form your city uses.
The report serves two purposes: it tells the city whether your device passed or failed, and it provides a detailed record of the device's performance that can be compared year over year to track its condition.
The Header: Property and Device Information
The top of the report contains identifying information:
- Property owner name and address — who owns the property where the device is installed
- Service address — the physical location of the backflow device (sometimes different from the mailing address)
- Water account or meter number — ties the report to your specific water service
- Device type — what kind of backflow preventer you have (RPZ, DCVA, PVB, etc.)
- Manufacturer, model, and serial number — identifies the specific device
- Device size — measured in inches (common sizes are 3/4", 1", 1.5", 2", 3", 4", 6", 8", and 10")
- Device location — where on the property the device is installed (e.g., "south side of building near parking lot")
This section is straightforward, but it's worth checking for accuracy. If the address, device type, or serial number is wrong, it can cause problems with the city's records. Let your tester know if anything looks off.
The Test Results: What the Numbers Mean
This is the meat of the report, and it's where things get technical. The specific tests performed depend on the type of backflow device you have. Let's go through the most common types.
Reduced Pressure Zone (RPZ) Assembly
An RPZ assembly has two check valves and a relief valve. The test report will show results for three components:
#1 Check Valve: This is the first check valve (closest to the supply side). The report shows the pressure differential across this valve, measured in pounds per square inch (psid). For the device to pass, the #1 check valve must hold at least 5.0 psid. If the report shows a number below 5.0, this check valve failed.
#2 Check Valve: This is the second check valve (closest to the downstream side). Same measurement — it needs to hold at least 5.0 psid to pass.
Relief Valve Opening Point: The relief valve is the safety mechanism that dumps water if the check valves fail. The report shows the differential pressure at which the relief valve opens. For a properly functioning RPZ, the relief valve should open at a differential of at least 2.0 psid but must open at a lower pressure than the #1 check valve reading. This ensures the relief valve activates before a backflow event can occur.
If you see your relief valve dripping or discharging water periodically, that's actually a sign it's doing its job — but it also means something may be wearing and it's time for a closer look.
Double Check Valve Assembly (DCVA)
A DCVA has two check valves but no relief valve. The test report shows:
#1 Check Valve: Must hold at least 1.0 psid to pass.
#2 Check Valve: Must hold at least 1.0 psid to pass.
The threshold is lower than an RPZ because DCVAs are used on lower-hazard connections. But the principle is the same — each check valve must create a measurable pressure barrier against backflow.
Pressure Vacuum Breaker (PVB)
A PVB has an air inlet valve and a check valve. The test report shows:
Air Inlet Valve Opening Point: The air inlet must open at least 1.0 psid above the last known downstream pressure. This valve lets air into the system to break the vacuum that would otherwise cause backflow.
Check Valve: Must hold at least 1.0 psid to pass.
Pass or Fail: The Bottom Line
At the bottom of the test results section, you'll see an overall determination: PASS or FAIL. If all components meet their minimum thresholds, the device passes. If any single component falls below its threshold, the entire device fails.
A passing report gets submitted to the city, and you're good for another year. A failing report means the device needs repair and retesting before you're in compliance.
The Repair Section
If your device failed and was repaired on-site, the report will include a repair section. This documents:
- What parts were replaced (check valve springs, seats, o-rings, relief valve disc, etc.)
- The repair kit or parts used
- The retest results after the repair
The retest results should show all components now passing their minimum thresholds. If the repair section shows a passing retest, your device is back in compliance.
Tester Information
The report includes information about the person who performed the test:
- Tester name
- License number — in Texas, backflow testers must hold a valid license from TCEQ
- Company name
- Test date
- Test gauge serial number and calibration date — the test gauge must be calibrated annually for the results to be valid
The gauge calibration date is important. If the gauge wasn't calibrated within the past 12 months, the test results are technically invalid. A reputable tester will always use a properly calibrated gauge.
What to Look For on Your Report
You don't need to become a backflow expert, but here are a few things worth checking when you receive your report:
- Is the device information correct? Wrong serial numbers or device types can cause confusion with the city.
- Did it pass or fail? This is the most important thing on the report.
- Are the numbers close to the minimum? A check valve that's holding at 5.2 psid on an RPZ is technically passing, but it's close to the 5.0 minimum. That might mean it'll fail next year, and you could consider proactive repair.
- Is the gauge calibration current? The calibration date should be within the past 12 months.
- Was the report submitted to the city? Your tester should handle this, but it's worth confirming.
Trending: Watching Your Device Over Time
If you keep your reports from year to year (and you should), you can track how your device is aging. A check valve that tested at 12.0 psid three years ago, 8.0 psid two years ago, and 5.5 psid this year is clearly declining. Even though it's still passing, the trend tells you a repair is coming soon. Being proactive about this can save you from a failed test and the compliance headaches that come with it.
We're Here to Explain
At 1-A Services, we don't just hand you a report and drive away. We're happy to walk you through the results, explain what the numbers mean, and let you know if we see anything that might need attention down the road. We're a family business, and we believe in treating our customers like people, not account numbers.
If you've got a backflow test report sitting on your desk and you're not sure what it means, give us a call. We'll explain it in plain English — no charge, no pressure.
