All Star Plumbing
90/100 ✓ CA Utility-Approved Tester Verified ★ 4.9 (145 reviews) On City of Napa list Backflow Testing
Verified Oct 2026 · Unclaimed listing
Approved backflow testers in Napa, CA
21 backflow testing businesses work within 25 miles of Napa, 3 of them based in town. Every one is on the approved tester list of 10 water utilities.
21 businesses within 25 miles
Backflow testing companies near Napa
What the badges mean
- ✓ CA Utility-Approved Tester Verified On the city list
- The company is on a water utility's own approved list (the second badge names the list). That is the utility's approval, not a state license, and it counts for that utility.
- 3 certified testers
- How many certified testers the roster lists at this business.
- ★ 4.8 (25 reviews)
- The Google rating, shown as Google reports it. It does not change the order.
Order is by our quality score, never by payment. How we verify listings.
Are you a backflow testing company near Napa? One sponsor per county, clearly labelled. Sponsor this county
Heritage Systems Inc
90/100 ✓ CA Utility-Approved Tester Verified On City of Napa list Backflow Testing
Verified Oct 2026 · Unclaimed listing
McLean & Williams, Inc
90/100 ✓ CA Utility-Approved Tester Verified ★ 4.8 (33 reviews) On City of Napa list Backflow Testing
Verified Oct 2026 · Unclaimed listing
Cagwin & Dorward
100/100 ✓ CA Utility-Approved Tester Verified ★ 3.4 (10 reviews) 2 certified testersOn DSRSD listOn City of Milpitas listOn North Marin Water District listOn City of Tracy listOn City of Petaluma list Backflow Testing
Verified Oct 2026 · Unclaimed listing
City Mechanical Inc.
90/100 ✓ CA Utility-Approved Tester Verified ★ 2.8 (12 reviews) On EBMUD listOn San Francisco authorized testersOn DSRSD list Backflow Testing
Verified Oct 2026 · Unclaimed listing
Arolo Company Inc
90/100 ✓ CA Utility-Approved Tester Verified ★ 2.7 (18 reviews) On City of Petaluma list Backflow Testing
Verified Oct 2026 · Unclaimed listing
Matrix
100/100 ✓ CA Utility-Approved Tester Verified ★ 3.6 (43 reviews) 3 certified testersOn EBMUD listOn San Francisco authorized testersOn City of Pleasanton list Backflow Testing
Verified Oct 2026 · Unclaimed listing
Service Plumbing
90/100 ✓ CA Utility-Approved Tester Verified On City of Petaluma listOn Forestville Water District list Backflow Testing
Verified Oct 2026 · Unclaimed listing
Ongaro & Sons
90/100 ✓ CA Utility-Approved Tester Verified ★ 4.9 (766 reviews) On City of Petaluma list Backflow Testing
Verified Oct 2026 · Unclaimed listing
Dolcini Plumbing, Inc
90/100 ✓ CA Utility-Approved Tester Verified ★ 4 (19 reviews) On City of Petaluma list Backflow Testing
Verified Oct 2026 · Unclaimed listing
GAC Plumbing Company
90/100 ✓ CA Utility-Approved Tester Verified ★ 5 (3 reviews) On City of Petaluma list Backflow Testing
Verified Oct 2026 · Unclaimed listing
Landscape Care, Inc
90/100 ✓ CA Utility-Approved Tester Verified ★ 4 (4 reviews) On EBMUD listOn DSRSD list Backflow Testing
Verified Oct 2026 · Unclaimed listing
Guerra Bros Plumbing
90/100 ✓ CA Utility-Approved Tester Verified ★ 4.7 (38 reviews) On EBMUD listOn San Francisco authorized testers Backflow Testing
Verified Oct 2026 · Unclaimed listing
Preferred Plumbing & Drain
90/100 ✓ CA Utility-Approved Tester Verified ★ 4.3 (133 reviews) On EBMUD listOn City of Pleasanton listOn City of Tracy list Backflow Testing
Verified Oct 2026 · Unclaimed listing
Mike Testa Plumbing, Inc.
90/100 ✓ CA Utility-Approved Tester Verified ★ 4.4 (29 reviews) On North Marin Water District list Backflow Testing
Verified Oct 2026 · Unclaimed listing
✓ CA Utility-Approved Tester Verified ★ 4.8 (129 reviews) On City of Petaluma list Backflow Testing
Verified Oct 2026 · Unclaimed listing
Scott Cramer Plumbing
80/100 ✓ CA Utility-Approved Tester Verified On City of Petaluma list Backflow Testing
Verified Oct 2026 · Unclaimed listing
Jackson & Son Plumbing
80/100 ✓ CA Utility-Approved Tester Verified ★ 3.7 (3 reviews) On DSRSD listOn City of Pleasanton listOn City of Milpitas listOn City of Tracy list Backflow Testing
Verified Oct 2026 · Unclaimed listing
✓ CA Utility-Approved Tester Verified ★ 5 (4 reviews) On North Marin Water District list Backflow Testing
Verified Oct 2026 · Unclaimed listing
The Landscape Company
80/100 ✓ CA Utility-Approved Tester Verified On EBMUD list Backflow Testing
Verified Oct 2026 · Unclaimed listing
Beasley Plumbing Inc.
80/100 ✓ CA Utility-Approved Tester Verified On DSRSD list Backflow Testing
Verified Oct 2026 · Unclaimed listing
Price reports
What a backflow test costs in Napa
Not enough reports yet for Napa to show a range. Be one of the first: it takes a minute and stays anonymous.
Published prices nationwide
$29.99 to $100 per assembly
$0$25$50$75$100$125
Every published price, with its source: what a backflow test costs.
Failed test? Published repair, rebuild and replacement prices: what a backflow repair or replacement costs.
Metro guide: Backflow testing in Oakland and San Francisco: every utility's rules, filing portals and published prices in one place.
Never miss your annual backflow test
Most water utilities require the backflow assembly on an irrigation, fire or commercial line to be tested every year, and a missed test can mean a shutoff notice. Tell us when yours was last tested in Napa and we'll text you a month before it is due, with certified local testers ready to book.
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Backflow testing questions in Napa
Where are the backflow testing businesses listed for Napa based?
21 backflow testing businesses are listed within 25 miles of Napa. 3 are based in Napa itself and 18 further out, up to 25 miles away. Other towns with more than one listing: Petaluma (7), Concord (3) and Hercules (2). The closest is All Star Plumbing, under 1 mile from Napa.
Which tester lists are the businesses near Napa on?
Every one is on the approved tester list of 10 water utilities.
How many of the backflow testing businesses near Napa have Google reviews?
16 of the 21 listed for Napa have 3 or more Google reviews. Ongaro & Sons has the most reviews, 766, with an average of 4.9 stars, as Google showed them at our last check.
Approved list: City of San Diego approved backflow testers, City of San Diego Public Utilities Department.
Approved list: Sweetwater Authority certified backflow testers, Sweetwater Authority.
Approved list: Cucamonga Valley Water District backflow assembly testers list, Cucamonga Valley Water District.
Approved list: Otay Water District approved backflow prevention assembly testers, Otay Water District.
Approved list: EVMWD backflow tester list, Elsinore Valley Municipal Water District.
Approved list: Ventura County certified backflow device tester list, County of Ventura Resource Management Agency.
Approved list: Yorba Linda Water District backflow prevention device testers, Yorba Linda Water District.
Approved list: Riverside Public Utilities backflow tester list, Riverside Public Utilities.
Approved list: City of Redlands backflow tester list (BSI), City of Redlands Municipal Utilities.
Approved list: Western Municipal Water District certified backflow prevention testers, Western Municipal Water District.
Approved list: Rancho California Water District approved backflow testers, Rancho California Water District.
Approved list: Sacramento County certified backflow prevention assembly testers, Sacramento County Environmental Management Department.
Approved list: Olivenhain Municipal Water District certified backflow prevention assembly testers, Olivenhain Municipal Water District.
Approved list: EBMUD approved backflow testers, East Bay Municipal Utility District.
Approved list: Irvine Ranch Water District backflow tester list, Irvine Ranch Water District.
Approved list: San Francisco authorized backflow assembly testing companies, San Francisco Department of Public Health.
Approved list: Padre Dam Municipal Water District approved backflow tester list, Padre Dam Municipal Water District.
Approved list: DSRSD backflow tester list, Dublin San Ramon Services District.
Approved list: City of Palo Alto approved backflow testers, City of Palo Alto Utilities.
Approved list: City of Pleasanton approved backflow prevention testers, City of Pleasanton Water.
Approved list: Certified Backflow Prevention Device Testers, Los Angeles County Public Health.
Approved list: Casitas Municipal Water District approved certified backflow device testers, Casitas Municipal Water District.
Approved list: City of Milpitas qualified backflow prevention assembly testers, City of Milpitas.
Approved list: City of Tracy approved backflow testers, City of Tracy Public Works.
Approved list: City of Long Beach backflow prevention testers, Long Beach Health.
Approved list: City of Ceres certified backflow tester list, City of Ceres.
Approved list: City of Petaluma city certified backflow testers, City of Petaluma.
Approved list: City of Clovis certified backflow testers, City of Clovis Public Utilities.
Approved list: Goleta Water District certified backflow tester listing, Goleta Water District.
Approved list: City of Napa certified backflow prevention testers, City of Napa Utilities.
Approved list: La Puente Valley County Water District approved list of backflow testers, La Puente Valley County Water District.
Approved list: Alameda County Water District approved backflow prevention testers, Alameda County Water District.
Approved list: West Valley Water District backflow tester list, West Valley Water District.
Approved list: Rainbow Municipal Water District certified backflow vendor list, Rainbow Municipal Water District.
Approved list: City of Lathrop approved backflow testers, City of Lathrop Public Works.
Approved list: North Marin Water District backflow assembly tester list, North Marin Water District.
Approved list: Calaveras County Water District recognized BPA testers, Calaveras County Water District.
Approved list: Diablo Water District list of certified backflow testers, Diablo Water District.
Approved list: Forestville Water District approved certified backflow device testers, Forestville Water District.
Keep looking
- Petaluma, CA(20 mi)
- Hercules, CA(20 mi)
- Martinez, CA(23 mi)
- Concord, CA(24 mi)
- San Rafael, CA(27 mi)
- Santa Rosa, CA(28 mi)
- Oakland, CA(35 mi)
- San Francisco, CA(38 mi)
- San Leandro, CA(40 mi)
- South San Francisco, CA(45 mi)