COMMON BACKFLOW DEVICE PROBLEMS

1. CONTINUOUS LEAKING FROM RELIEF VALVE

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What It Looks Like:
• Constant water dripping or flowing from relief valve
• Puddle or wet spot around device
• Water running continuously
• Relief valve won't stop flowing

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What Causes This?

Check Valve Failure:
• Debris preventing check valve from sealing
• Worn or damaged rubber seals
• Pitted valve seats
• Spring fatigue
• Sediment buildup

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Excessive Pressure Differential:
• Supply pressure too high
• Thermal expansion in system
• Pressure surges
• Improper device sizing

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Relief Valve Problems:
• Stuck open position
• Damaged diaphragm
• Weak or broken spring
• Debris in relief valve
• Worn relief valve seat

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Why It Matters:
• Wasting water (hundreds of gallons)
• High water bills
• Device will fail annual test
• Potential freeze damage in winter
• Indicates device not providing full protection

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Typical Repair Cost:
• Check valve replacement: $150-$300
• Relief valve replacement: $120-$280
• Complete rebuild: $350-$600
• Device replacement: $400-$1,200

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2. DEVICE FAILS ANNUAL TEST

What It Means:
• Device doesn't hold proper pressure
• Check valves not sealing
• Relief valve not operating correctly
• Fails to provide required protection

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Common Test Failures:

Check Valve #1 Failure:
• Won't close completely
• Leaks under test pressure
• Allows backflow
• Most common failure point

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Check Valve #2 Failure:
• Second line of defense compromised
• Similar causes to CV#1
• Often fails along with CV#1
• Critical for protection

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Relief Valve Failure (RPZ):
• Doesn't open at proper pressure
• Opens at wrong differential
• Won't close after opening
• Critical safety component

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Air Inlet Valve Failure (PVB):
• Won't open to admit air
• Stuck closed
• Prevents proper function
• Allows vacuum condition

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Why Devices Fail:

Age & Wear:
• Normal component aging (5-10 years)
• Rubber seals deteriorate
• Springs lose tension
• Metal parts corrode
• Sediment accumulation

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Water Quality Issues:
• Hard water mineral deposits
• Sediment and debris
• Corrosive water chemistry
• Chlorine degradation of rubber

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Environmental Factors:
• Freeze/thaw damage
• UV exposure (outdoor devices)
• Physical damage
• Improper installation

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What To Do:
• Technician will identify specific failure
• Get repair estimate
• Most repairs completed quickly
• Retest after repair
• Device replacement if too old or damaged

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Typical Resolution:
• Minor repair: $150-$300
• Major repair: $300-$600
• Device replacement: $400-$1,200
• Retest after repair: $50

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3. LOW WATER PRESSURE DOWNSTREAM

What You'll Notice:
• Reduced water pressure after device
• Sprinklers don't reach as far
• Weak water flow
• System doesn't work properly

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Common Causes:

Device Restrictions:
• Strainer clogged with debris
• Partially closed shutoff valves
• Device undersized for demand
• Internal fouling/buildup
• Frozen components (winter)

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System Issues:
• Main supply pressure dropped
• Multiple devices in series
• Piping too small
• Other restrictions in system
• Air in lines

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Device Damage:
• Check valves stuck partially closed
• Internal damage
• Corrosion blocking flow
• Foreign objects in device

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Solutions:

Immediate Checks:
• Verify shutoff valves fully open
• Check strainer for debris
• Inspect for visible damage
• Compare to supply pressure

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Professional Service May Require:
• Clean or replace strainer
• Remove debris from valves
• Device rebuild if internal issues
• Replace undersized device
• System evaluation

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Cost Range:
• Strainer cleaning: $80-$150
• Device cleaning: $120-$250
• Device replacement (if undersized): $400-$1,200

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4. FREEZE DAMAGE

What It Looks Like:
• Cracked device housing
• Split pipes at device
• Burst relief valve
• Leaking after winter
• Device won't hold pressure

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How It Happens:
• Water freezes in device
• Ice expands and cracks components
• Particularly affects exposed devices
• More common with RPZ devices (hold water)

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Prevention Methods:

For Irrigation Systems:
• Full system winterization
• Blow out all water with compressed air
• Drain device completely
• Insulate device if must stay charged
• Drain valve should be functional

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For Year-Round Systems:
• Insulate device properly
• Heat tape for extreme cold
• Enclosure with insulation
• Below-grade installation if possible
• Ensure proper drainage

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If Freeze Damage Occurs:
• Shut off water immediately
• Call for emergency service
• Assess damage extent
• Usually requires device replacement
• Repair or replace associated piping

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Typical Costs:
• Device replacement: $400-$1,200
• Pipe repairs: $200-$800
• Insulation installation: $100-$400
• Heated enclosure: $500-$2,000

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5. VISIBLE CORROSION & DETERIORATION

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What You See:
• Rust on metal components
• Green corrosion (copper/brass)
• Flaking or pitting
• Seized test cocks
• Deteriorated body

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Why It Happens:
• Age (10-15+ years)
• Water chemistry
• Outdoor exposure
• Galvanic reaction between metals
• Poor drainage around device

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Problems It Causes:
• Test cocks won't operate
• Cannot perform annual test
• Structural weakness
• Leaks developing
• Device may fail catastrophically

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When to Replace vs. Repair:
• Minor surface rust: Can test/repair
• Moderate corrosion: Repair questionable
• Severe corrosion: Replace device
• Pitted housing: Replace
• Seized components: Often replace

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Prevention:
• Protect from standing water
• Proper drainage
• Protective coatings (where appropriate)
• Regular inspection
• Replace before catastrophic failure

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6. MISSING OR DAMAGED TEST COCKS

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What's Wrong:
• Test cocks broken off
• Caps missing
• Won't open or close
• Leaking from test ports

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Why It Matters:
• Cannot perform annual test without test cocks
• Leaking test cocks waste water
• Open ports contaminate system
• Missing caps allow debris entry

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Common Causes:
• Physical damage (lawn equipment)
• Corrosion
• Freeze damage
• Vandalism
• Aging

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Solutions:
• Replace test cocks: $80-$150
• Replace caps: $20-$50
• Full device replacement if severely damaged

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Prevention:
• Protect device from lawn equipment
• Keep area clear
• Regular inspection
• Replace caps immediately if lost

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7. DEVICE INSTALLED INCORRECTLY

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Common Installation Problems:

Wrong Location:
• PVB not 12" above highest outlet
• Device in inaccessible location
• Insufficient clearance for testing
• Below grade (RPZ in vault)
• Too close to building foundation

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Improper Orientation:
• Device installed backwards
• Not level (affects relief valve)
• Wrong angle for drainage

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Missing Components:
• No shutoff valves
• Missing strainer
• No drain valve
• No test cocks
• Inadequate support

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Results:
• Device won't function properly
• Cannot test properly
• Fails inspections
• Must be reinstalled correctly

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Cost to Correct:
• Minor repositioning: $200-$500
• Major relocation: $500-$2,000
• Complete reinstallation: $1,000-$3,000

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8. DEBRIS & FOULING

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What Causes This:
• Sediment in water supply
• Construction debris
• Pipe scale
• Well water particulates
• Water main break residue

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How It Affects Device:
• Prevents check valves from sealing
• Clogs relief valve
• Blocks test cocks
• Restricts water flow
• Causes premature failure

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Prevention:
• Install strainer upstream
• Clean strainer regularly
• Address water quality issues
• After water main work, flush system

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Cleaning:
• Professional device cleaning: $120-$250
• Strainer cleaning: $80-$120
• May require disassembly
• Check valves may need replacement