Why Is Water Leaking Or Dripping From My Backflow Preventer?

A drip usually means your device is doing its job—or needs service. Many backflow preventers discharge water by design when they detect unsafe pressure conditions. But persistent leaking, heavy discharge, or water appearing at the wrong place often signals worn internal parts, debris, freeze damage, or installation issues.

Getting the Backflow Testing Los Angeles experts recommend will pinpoint the cause, protect your water quality, and prevent property damage.Atlas Backflow Services provides certified diagnostics, repairs, and documentation so your system stays compliant and dry.

First, Know Which Backflow Preventer You Have

Different assemblies behave differently when they “leak.” Identifying the type helps diagnose the cause:

• RPZ (Reduced Pressure Zone): Has a relief port that will discharge water to atmosphere. A small, occasional drip can be normal under certain pressure changes; continuous flow is not.

• DCVA (Double Check Valve Assembly): Fully contained; should not discharge water outside the valve body. Any external leak signals a problem.

• PVB (Pressure Vacuum Breaker) / SVB: Used often on irrigation; can spit briefly when zones turn on/off. Constant dripping at the bonnet or test cocks indicates issues.

• Dual Check/Residential check: Non-testable. External leaks or fixture issues may point to replacement or system problems elsewhere.

If you’re unsure, snap a photo and contact Atlas Backflow Services. We’ll advise next steps and schedule the Backflow Testing Los Angeles experts recommend.

Common Reasons Backflow Preventers Leak

• Debris in check valves or relief valve

  
  

  Sand, scale, or rust can lodge in the internal rubber seats and springs, preventing a tight seal. RPZs may discharge from the relief port; PVBs may drip from the bonnet or test cocks.

• Worn rubber parts

  
  

  Seats, discs, and O‑rings wear out over time—especially with hard water—leading to weeping or intermittent leaks. Rebuild kits typically resolve this.

• Pressure fluctuations or thermal expansion

  
  

  Sudden upstream pressure spikes or downstream thermal expansion (from a water heater on a closed system) can lift an RPZ relief valve, causing discharge. An expansion tank may be needed.

• Failed or misadjusted pressure reducing valve (PRV)

  
  

  If the PRV upstream fails, system pressure can rise and push an RPZ to dump water.

• Backpressure or backsiphonage events

  
  

  Irrigation pumps, elevation changes, or sudden high demand can create conditions that intentionally open an RPZ’s relief port to protect the potable supply.

• Freeze or heat damage

  
  

  Even in Los Angeles, a cold snap can crack bonnets or poppet housings on PVBs or damage check bodies, leading to visible leaks once the system repressurizes.

• Improper installation or stress

  
  

  Incorrect orientation, lack of proper support, or piping strain can distort the body or seals, causing chronic drips.

• Open or faulty test cocks

  
  

  A test cock left slightly open during prior testing or with failed washers will drip until serviced.

• Downstream leak keeping the valve “active”

  
  

  Constant downstream flow (e.g., a leaking irrigation zone) can mask other issues or cause nuisance discharges.

Atlas Backflow Services diagnoses these conditions and performs the Backflow Testing Los Angeles experts recommend to confirm internal performance after repairs.

Is Any Leaking “Normal”?

• RPZ: A brief spit during rapid pressure changes can be normal. Continuous or heavy discharge is not and needs service.

• PVB/SVB: A short burp when zones start is common. Steady dripping at rest signals debris, worn parts, or freeze damage.

• DCVA: No external water should be seen. Any drip indicates a problem with plugs, gaskets, or the body.

Important safety note: Never cap or plug an RPZ relief port. It’s a required safety outlet. Capping can create hazardous cross-connection conditions and violate code.

What To Do Right Now

1. Identify the leak location

   
   

   Relief port? Bonnet? Test cocks? Body seams? A quick photo helps us prepare the right parts.

2. Check for obvious access issues

   
   

   Clear plants, debris, and locked enclosures for fast service.

3. Note when it leaks

   
   

   Only during irrigation cycles? Constantly? After hot water use? This timing guides diagnosis.

4. Don’t attempt makeshift fixes

   
   

   Tape, plugs, or clamps can worsen damage and create compliance risks.

5. Schedule the Backflow Testing Los Angeles experts recommend

   
   

   A certified test confirms internal check performance and relief valve opening points, then verifies the repair solved the root cause.

Atlas Backflow Services can often repair and re-test in one visit, minimizing downtime and water loss.

Repairs vs. Replacement: How We Decide

• Rebuild recommended when: Body is sound; leak traced to worn seats, springs, or O‑rings; device model has available kits. This is common and cost-effective.

• Replacement recommended when: Body is cracked/corroded, model is obsolete, repeated failures occur, or repairs exceed replacement cost. We’ll provide options and timelines.

Either way, we complete the Backflow Testing Los Angeles experts recommend after work is done and submit results to the utility as required.

Special Scenarios We See In Los Angeles

• Irrigation PVB dripping after a cold night

  
  

  Likely bonnet or poppet damage from freezing. A rebuild or bonnet replacement usually solves it.

• RPZ drains constantly after a new water heater

  
  

  Thermal expansion on a closed system is lifting the relief valve. Add/verify a properly sized expansion tank and test.

• Intermittent RPZ discharge in mixed-use buildings

  
  

  Upstream PRV drift or sporadic pressure spikes from street mains. We test, log pressures, and coordinate with your plumber/utility if needed.

• DCVA “mystery” leak at test cock

  
  

  A worn test cock washer or partially open valve. Simple fix plus a full retest.

These are routine for our team, and we’ll apply the Backflow Testing Los Angeles experts recommend to document compliance afterward.

Prevent Leaks With Proactive Maintenance

• Annual certified testing to catch weak checks before they drip.

• Periodic rebuilding based on water quality and usage; many devices benefit from 3–5 year rebuild cycles.

• Pressure management with a functioning PRV and properly sized thermal expansion tank.

• Seasonal protection for irrigation assemblies; insulate and drain where applicable.

• Keep enclosures ventilated to reduce heat stress yet protected from freezing conditions.

Enroll with Atlas Backflow Services for reminders, quick scheduling, and the Backflow Testing Los Angeles experts recommend to keep everything current.

FAQs

• Is a small drip harmful?

  
  

  It can waste water, damage landscaping or enclosures, and usually indicates a serviceable issue. Address it early.

• Can I shut my device off?

  
  

  You may isolate water temporarily to stop damage, but don’t leave a required assembly out of service. Schedule repair and testing promptly.

• Will the utility fine me for a leaking backflow?

  
  

  Utilities focus on testing compliance and cross-connection safety. A leaking device that’s not functioning properly can lead to a failed test and compliance notices if not resolved.

• How fast can you fix it?

  
  

  We offer rush appointments. Many repairs are completed same visit with on-vehicle kits, followed by the Backflow Testing Los Angeles experts recommend.

Stop The Drip With Atlas Backflow Services

Whether your RPZ is dumping water, your PVB won’t stop weeping, or your DCVA shows signs of leakage, our certified technicians will diagnose, repair, and perform the Backflow Testing Los Angeles experts recommend—fast.

We handle utility paperwork, provide digital certificates, and set reminders so you stay compliant year-round.Contact Atlas Backflow Services today to schedule service and keep your water safe, your system compliant, and your property dry.