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Licensed Plumbers in Castro Valley, California

Updated November 1, 2026 from CSLB's public license file · C-36 Plumbing Contractor

  • 24licensed plumbers
  • 24active (Clear)
  • 0%with a suspension
  • 58.3%workers' comp exempt
  • 13.1 yrsmedian time licensed
  • 45.8%corp / LLC / partnership (54.2% sole owner)
  • 2new in the last 12 months
  • —change tracking began November 1, 2026

There are 24 plumbers based in Castro Valley in CSLB's current file. 24 (100%) have a Clear status as of November 1, 2026.

58.3% report a workers' comp exemption, 7.1 points higher than the statewide figure for plumbers (51.2%), so many of these businesses say they have no employees. The share with a suspension, 0%, is 3.4 points lower than the Alameda County rate for the same license (3.4%).

The median plumber here has held a license for 13.1 years (less than the statewide median of 13.4), and 2 licenses were issued in the last 12 months.

In California this work generally calls for the C-36 Plumbing Contractor license (or a B license when it is part of a larger multi-trade job). See the C-36 Plumbing Contractor guide for what the license covers.

How to check a plumber's license in Castro Valley

  1. Look the company up by name or license number (search Castro Valley). On the profile, confirm three things: Clear status, the C-36 license for this kind of work, and a contractor's bond on file.
  2. Before any money changes hands, verify the license on CSLB's own lookup. Our data comes from CSLB's weekly file, so a very recent change may not show here yet.
  3. Ask for the pocket license and a photo ID and match the name to your contract. Work of $1,000 or more needs a license (the $1,000 rule), and a down payment can't exceed $1,000 or 10% (down payment rules).

All 24 plumbers in Castro Valley

Castro Valley plumbers sorted with Clear licenses first, then by years licensed. Badges reflect CSLB's file dated November 1, 2026, not a rating of anyone's work.

Licensed plumbers in Castro Valley
Business nameLicense #StatusYearsWorkers' compBond
Bonetti Frank Plumbing INC 251165 Clear 58 Insured On file
Demiguel Plumbing 406575 Clear 45 Insured On file
Mc Donagh John Builders and Energy Systems 422946 Clear 44 Exempt On file
Lambros Elias Plumbing 561709 Clear 37 Exempt On file
Bri-Carr Plumbing 658310 Clear 34 Exempt On file
Streamline Plumbing & Drain CO 672250 Clear 33 Insured On file
All Fixture Plumbing 774779 Clear 26 Exempt On file
Mc Carthy Patrick 806963 Clear 24 Exempt On file
Clearwater Plumbing 872069 Clear 20 Exempt On file
Just Plumbing INC 909971 Clear 18 Insured On file
Houston Plumbing 960208 Clear 15 Insured On file
Water Heater Company 987574 Clear 13 Exempt On file
California Builders 988161 Clear 13 Insured On file
Alligator Plumbing INC 995431 Clear 12 Insured On file
Baek Construction 1002450 Clear 11 Exempt On file
Buchmann INC 1004484 Clear 11 Insured On file
Harris Water Heaters INC 1026214 Clear 9 Insured On file
Gaxl General Construction INC 1037436 Clear 8 Insured On file
Aaa Plumbing & Remodeling INC 1052769 Clear 7 Exempt On file
Proper Plumbing Services LLC 1100951 Clear 3 Exempt On file
Blu Pipe Plumbing LLC 1132566 Clear 1 Exempt On file
Garibay Olga Plumbing 1139028 Clear 1 Exempt On file
Bluewave Plumbing and Water Heaters LLC 1151565 Clear <1 Exempt On file
Wong Plumbing 1158954 Clear <1 Exempt On file

Source: CSLB public data · Updated November 1, 2026 Status can change at any time. Verify on CSLB's Instant License Check.

Frequently asked questions

How many licensed plumbers are in Castro Valley?

CSLB's current public file lists 24 plumbers with a Castro Valley mailing address. 24 have a Clear status, and 95.8% show no issues at all in the file (no suspension, no pending action, bond on file, not near expiration).

What license does a plumber need in California?

Look for C-36 on the license. 24 businesses in Castro Valley hold it. Small jobs under $1,000 with no permit and no employees are exempt; everything else needs a license (details).

How do I check a plumber's workers' comp?

Each profile shows the workers' comp type, insurer and policy dates from CSLB's file. Among Castro Valley plumbers, 58.3% are exempt (no employees), 41.7% insured and 0% without current coverage. Verify a policy with CSLB's insurer search (step by step).

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Guides