Independent site · Not affiliated with CSLB or any state agency
Contractor LookoutCalifornia

Licensed Plumbers in Diamond Bar, California

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

  • 27licensed plumbers
  • 26active (Clear)
  • 3.7%with a suspension
  • 63%workers' comp exempt
  • 25 yrsmedian time licensed
  • 22.2%corp / LLC / partnership (77.8% sole owner)
  • 1new in the last 12 months
  • —change tracking began November 1, 2026

CSLB's public data lists 27 plumbers with a mailing address in Diamond Bar, and 26 of them (96.3%) show a Clear primary status.

63% report a workers' comp exemption, 11.8 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 (3.7%) is close to the Los Angeles County rate for the same license (4.6%).

Experience varies: 74.1% have been licensed 10+ years and 1 is new this year (median 25 years, vs 13.4 statewide).

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 Diamond Bar

  1. Look the company up by name or license number (search Diamond Bar). 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 27 plumbers in Diamond Bar

Diamond Bar 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 Diamond Bar
Business nameLicense #StatusYearsWorkers' compBond
A E D Contractors 441036 Clear 43 Exempt On file
Jay's Plumbing 622850 Clear 35 Exempt On file
Fedorow Michael Steven 652125 Clear 34 Exempt On file
Cal Steam Company 674646 Clear 33 Insured On file
Monair Contractors 677543 Clear 33 Exempt On file
G C Plumbing 681446 Clear 32 Exempt On file
C - Thirty - Six INC 739644 Clear 29 Insured On file
Zip Renovation & Air 762505 Clear 27 Insured On file
Liao Hsueh Yu 769733 Clear 27 Exempt On file
Ace Plumbing CO 785570 Clear 26 Exempt On file
Service Wizards 797071 Clear 25 Insured On file
Daley Kenneth Heating & Air Services 798187 Clear 25 Insured On file
Rooter Shooter 800418 Clear 25 Exempt On file
Chien Ming Chu Chen 820540 Clear 23 Exempt On file
J H Plumbing 876263 Clear 20 Exempt On file
Mirae Construction CO 876472 Clear 20 Insured On file
Jones Plumbing 917266 Clear 18 Exempt On file
Expedite Plumbing 939646 Clear 17 Exempt On file
Aveo INC 969881 Clear 14 Insured On file
Galvan Plumbing 1065435 Clear 6 Insured On file
Thlc Corporation 1077041 Clear 5 Insured On file
All Day Drains 1088634 Clear 4 Exempt On file
Advanced Tankless and Plumbing 1121827 Clear 2 Exempt On file
Cany Fire Protection INC 1142986 Clear 1 Exempt On file
Elite Pipe P 1144688 Clear 1 Exempt On file
Vanguard Plumbing 1161936 Clear <1 Exempt On file
Jh Builder and Remodeling INC 751479 Susp: workers' compensation 28 None 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 Diamond Bar?

CSLB's current public file lists 27 plumbers with a Diamond Bar mailing address. 26 have a Clear status, and 96.3% 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?

CSLB issues the C-36 Plumbing Contractor classification for this work. In Los Angeles County, 96.3% of Diamond Bar's holders are Clear right now. The license requirement starts at $1,000 per job (the minor-work rule).

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 Diamond Bar plumbers, 63% are exempt (no employees), 33.3% insured and 3.7% without current coverage. Verify a policy with CSLB's insurer search (step by step).

Related

Plumbers in nearby cities

More plumbers lists in Los Angeles County

Other licensed trades in Diamond Bar

Guides