Emergency Backflow Repairs: What to Do When Your System Fails

Plumbing problems have a way of showing up at the worst possible moment. 

One minute everything’s working fine, and the next, you’re dealing with water pooling near a valve or an unexpected issue flagged during a routine inspection. 

If your backflow preventer is the problem, it's necessary to have fast action.

In this article, we'll help you understand the situation a little better. If your system has failed or something seems wrong, we’ll walk you through how to fix backflow preventer issues quickly and safely, so your water supply stays protected and compliant.

What is the Main Purpose of a Backflow Preventer?

A backflow preventer is designed to keep contaminated water from flowing backward into the clean water supply. When pressure changes occur in a plumbing system, there’s a risk that water from irrigation lines, industrial systems, or other non-drinking sources can reverse direction. 

The backflow preventer acts as a safeguard that maintains the quality or integrity of the drinking water.

In areas like San Diego, regulations require these devices on properties where cross-connections exist, helping ensure safe and compliant water systems. These requirements come from multiple layers of regulation, including the California Plumbing Code, which sets installation standards, and Title 17 of the California Code of Regulations, which outlines when and where backflow prevention is needed. 

San Diego’s Public Utilities Department also enforces local compliance, requiring annual testing of approved backflow assemblies and submission of test results to prevent contamination of the city’s drinking water supply.

What Causes a Backflow Preventer to Fail?

Backflow preventers can fail for several reasons, most of which come down to age, environment, or lack of maintenance. Common causes include:

• Worn-out internal parts. Components like springs, rubber seals, and check valves naturally degrade over time and may no longer seal properly.

• Exposure to extreme temperatures. Freezing can cause internal cracks, while prolonged heat can dry out or warp materials, especially in outdoor setups.

• Mineral or debris buildup. Hard water and sediment can clog or block parts inside the assembly, preventing it from working as intended.

• Improper installation. If the device wasn’t installed correctly from the start, it may never have functioned properly or could be misaligned.

• Skipped maintenance or testing. Systems that go too long without inspection or testing are more likely to fail due to unnoticed damage or wear.

  
  

When any of these issues go unchecked, the preventer can stop doing its job, putting your whole water supply at risk.

How to Tell If a Backflow Preventer is Broken?

A backflow preventer doesn’t always stop working with a dramatic failure. In many cases, small issues build up over time until the system no longer functions correctly. Knowing what to watch for can help you catch problems early before they turn into larger, more expensive repairs.

Here are some common signs that something may be wrong:

• Visible leaks or dripping around the device. Even a slow, consistent drip near the assembly can signal a failing seal or damaged internal part.

• Sudden or uneven water pressure. If you notice weak pressure in one part of the property or it changes throughout the day, there may be a blockage or malfunction inside the preventer.

• Discoloration or cloudy water at the tap. Any change in the appearance of your water could mean unwanted substances are entering the supply due to a compromised backflow barrier.

• Unusual smells or tastes in the water. Metallic, chemical, or sewage-like odors can point to contamination, and that’s a major red flag.

• Gurgling or hissing sounds in the plumbing. Strange noises may indicate air is entering the system or pressure is escaping where it shouldn’t.

• Water pooling near the backflow assembly. Standing water around the unit might look like a small nuisance but often points to a serious leak.

• Failed test results. If your most recent annual backflow test didn’t pass, the system likely needs immediate attention.

  
  

Can You Repair a Backflow Preventer?

In many cases, yes. A backflow preventer can be repaired rather than replaced. If the damage is limited to internal parts like springs, seals, or check valves, a certified technician can often rebuild the device and restore it to proper working condition.But not all issues can be fixed with a simple part swap. If the housing is cracked, the unit has extensive corrosion, or it no longer meets current compliance standards, replacement might be the safer and more cost-effective option.

Keep in mind, backflow assemblies are highly regulated. Repairs must be handled by a licensed and certified professional who understands local plumbing codes and testing requirements. 

If you're considering DIY repairs, know that this often leads to system failure, non-compliance, or worse, contaminated water. Better to let a professional handle it in the first place!

How to Fix a Backflow Preventer

When your system fails, the first step is to stay calm and act quickly. Knowing how to fix a backflow preventer starts with recognizing what you can safely do in the moment and when it’s time to bring in a professional.

Temporary Emergency Steps You Can Do

If you suspect your backflow preventer is leaking, broken, or compromised, these are the first actions you should take:

• Shut off the water supply - If it’s safe to do so, turn off the main water line or the isolation valve for the affected system. This helps prevent further damage or contamination.

• Contain any visible leaks - Place a bucket, towel, or absorbent material around the area to control pooling water until help arrives. Keep the area clear to avoid additional damage.

• Call a certified technician immediately - Emergency backflow issues should never be left to chance. Contact a licensed professional right away for assessment and repair.

  
  

When Professional Repair Comes In

A certified technician will follow a step-by-step process to restore your system and ensure it meets all compliance requirements:

• Diagnose the issue and isolate the problem area - The technician will test the assembly and inspect each internal component to find the exact source of failure.

• Repair or replace damaged parts - If the issue involves worn or damaged check valves, seals, or springs, these parts can typically be rebuilt or replaced on the spot.

• Retest the system - After the repair is complete, the system must be retested to verify it’s working properly and preventing backflow as required.

• Submit results to the water district - In San Diego, passing test results must be documented and submitted to the city to confirm compliance. We take care of that for you.

  
  

How Long Do Backflow Preventers Last?

Backflow preventers are built to last, but they don’t last forever. On average, most systems have a lifespan of 5 to 10 years, or 25 years at most. That range depends heavily on the environment, how often the system is used, and whether it receives regular testing and maintenance.

Systems exposed to extreme temperatures, hard water, or heavy usage may wear out faster. On the other hand, assemblies that are properly maintained and tested annually tend to stay in service longer and perform more reliably.

Don’t Wait for a Small Problem to Get Worse

At San Diego Backflow Testing, we specialize in fast, compliant repairs. When something goes wrong, we don’t just fix the problem, we handle the testing, documentation, and communication with the water district on your behalf. 

Need emergency service? Contact our licensed team today to fix your backflow preventer and submit compliance paperwork on your behalf.

Upload your test form or email it to Test@sandiegobackflowtesting.com and we’ll handle the rest. 

You may also call 877-363-8378 or visit our website to get started.