Backflow Testing

Backflow prevention devices keep contaminated water from flowing backwards into the public drinking-water supply. In Seattle and most cities in King and Pierce counties, these devices must be tested annually by a certified tester and the results submitted to the water purveyor.

All Phase Plumbing's certified backflow assembly testers (BATs) perform annual testing, send the report to your water utility, and repair or replace failed assemblies.

Call (206) 772-6077 to schedule annual backflow testing.

Who Needs Backflow Testing?

Most properties with any of the following require annual backflow testing:

• Irrigation systems with in-ground sprinklers
• Fire sprinkler systems
• Boilers connected to potable water
• Commercial kitchens and dishwashers
• Multi-family or commercial buildings with dedicated water service
• Pools, spas, or auxiliary water sources

Our Backflow Services

• Annual backflow assembly testing (RPZ, DCVA, PVB)
• Certified test results submitted directly to your water utility
• Repair of failed assemblies
• New backflow assembly installation
• Replacement of expired or non-compliant devices

What Happens During a Test

Testing takes 20–40 minutes per assembly. We isolate the device, run a series of pressure differential tests with calibrated gauges, document the results, and submit the certification to your water utility. If the device fails, we'll review repair vs. replacement options on the spot.

Schedule Backflow Testing

Backflow tests are due annually and missing the deadline can result in water-service shutoff. Call (206) 772-6077 and we'll get you tested and certified.