Backflow Testing & Repair · Los Angeles & SoCal
Backflow testing that keeps your water safe and your provider happy.
Annual backflow testing, repair and replacement for homes and businesses.
A backflow preventer stops irrigation water, chemicals and other contamination from being pulled back into the drinking water supply. Water providers typically require these devices to be tested every year.
We test your assembly, repair or rebuild it if it fails, and replace it when it's past saving — for homes with irrigation, fire lines, and businesses.
Signs you need this
- You received an annual backflow test notice
- Your device failed a test
- A backflow preventer is leaking or dripping
- New irrigation, fire line or commercial build-out
What's included
- Backflow assembly testing
- Repair and rebuild of failed devices
- Backflow preventer replacement
- Test results provided for your water provider
Why Leon Plumbing
- Homes, landscapes and businesses
- Fast scheduling around your notice deadline
- In business since 1983
Backflow Testing & Repair: common questions
How often does backflow need testing?
Many water providers require annual testing for regulated backflow assemblies, with additional testing after installation, repair or replacement. The exact requirements depend on your provider, assembly and property use, so follow the deadline and instructions on your notice. Providers may require an approved tester and a specific report format. When you call, have the notice, property address and device information available so the requirements can be checked before scheduling. Confirm who is responsible for submitting the results rather than assuming a test automatically completes the provider's paperwork.
What happens if my backflow device fails?
A failed test means the assembly needs assessment; it should not be treated as compliant until the required corrective work and retest are complete. Debris, worn seals, faulty check valves or relief-valve problems may be repairable, while severe deterioration or unavailable parts may make replacement more appropriate. We explain the findings and options before work proceeds. Completion depends on device condition, parts availability and your provider's requirements, so an immediate passing result is not guaranteed. Plan for any necessary water interruption and confirm the retest and reporting steps.
Backflow Testing & Repair near you
Google reviews
What Leon Plumbing customers say
Leon Plumbing on Google
4.9 out of 5 · 129 reviews
“Leon Plumbing’s team were great to work with! I had a minor leak coming from my kitchen sink and the team came out immediately and fixed the problem. Communication was easy and straightforward. Thank you to our tech Mario and Datevig and Sevan for a smooth experience!”
Erika Liu Wong
via Google“I needed a service for a Rinnai tankless water heater for a tenant in Eagle Rock. I called Leon plumbing and was surprised that they could have a tech out in about an hour. The tech did a complete service for $275, which seemed somewhat reasonable, and a needed valve replacement for another $275, which (though steep) was at least done quickly. I would recommend them for speed, good communications, and quality of the work.”
Steve Wolf
via Google“Excellent service! Sevag was super helpful and the team came out very quickly, fixed our water heater and made the whole process easy. We are extremely happy with their outstanding work and we highly recommend them!”
Despina Spanidou
via Google“As always, excellent service. This is my go-to plumber. Reliable, responsive, efficient.”
Steven Graubard
via Google“Very good service and anytime I call ready for the service god bless them 🙏”
Kevork Ashjian
via Google“⭐⭐⭐⭐⭐ Sevag is excellent! He is professional, reliable, and knowledgeable, and takes pride in doing quality work. He explains everything clearly, is dependable, and makes sure the job is done right. It’s hard to find someone you can trust, and Sevag definitely delivers! I highly recommend him to anyone looking for outstanding plumbing services.”
Joseph Khankhanian
via GoogleLatest written reviews from our main Leon Plumbing listing · Updated Oct 30, 2026
Gas & Commercial in our core communities
Leon Plumbing Advantage
Pay less for every plumbing visit — for $34.99/mo.
- Free $149 whole-home inspection
- $99 dispatch fee waived*
- 10% off all repairs & labor
- Same / next-day priority
- 2-year workmanship warranty
- 50% off after-hours premium