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Licensed HVAC Contractors in Diamond Bar, California

Updated November 1, 2026 from CSLB's public license file · C-20 Warm-Air Heating, Ventilating and Air-Conditioning Contractor

  • 34licensed HVAC contractors
  • 33active (Clear)
  • 2.9%with a suspension
  • 0%workers' comp exempt
  • 8.4 yrsmedian time licensed
  • 44.1%corp / LLC / partnership (55.9% sole owner)
  • 3new in the last 12 months
  • —change tracking began November 1, 2026

CSLB's public data lists 34 HVAC contractors with a mailing address in Diamond Bar, and 33 of them (97.1%) show a Clear primary status.

The share with a suspension, 2.9%, is 1.9 points lower than the Los Angeles County rate for the same license (4.8%). About 0% report a workers' comp exemption, roughly the statewide norm for HVAC contractors.

3 of these licenses are less than a year old, while 47.1% have been held for 10 years or more. The median is 8.4 years.

In California this work generally calls for the C-20 Warm-Air Heating, Ventilating and Air-Conditioning Contractor license (or a B license when it is part of a larger multi-trade job). See the C-20 Warm-Air Heating, Ventilating and Air-Conditioning Contractor guide for what the license covers.

How to check a HVAC contractor'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-20 license for this kind of work, and a contractor's bond on file.
  2. Re-check the same number on CSLB's Instant License Check the day you sign; our copy is refreshed weekly and 2.9% of Diamond Bar listings here already show a suspension.
  3. Match the license holder's name to the name on the written contract and the person you meet. Ask for proof of workers' comp if anyone besides the owner will work on site. Hiring checklist.

All 34 HVAC contractors in Diamond Bar

Diamond Bar HVAC contractors 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 HVAC contractors in Diamond Bar
Business nameLicense #StatusYearsWorkers' compBond
Mac Refrigeration and Air Conditioning CO 580557 Clear 37 Insured On file
Atlantic Air Conditioning INC 613226 Clear 35 Insured On file
Ace Rodil Heating and Air Conditioning 631042 Clear 35 Insured On file
Cal Steam Company 674646 Clear 33 Insured On file
Zip Renovation & Air 762505 Clear 27 Insured On file
Service Wizards 797071 Clear 25 Insured On file
Daley Kenneth Heating & Air Services 798187 Clear 25 Insured On file
Green Air & Refrigeration 839148 Clear 22 Insured On file
Mr A/C 864636 Clear 21 Insured On file
McMaster Mechanical 879152 Clear 20 Insured On file
Gary's AC Services 921063 Clear 18 Insured On file
Likai Chen HVAC INC 926434 Clear 17 Insured On file
Four Seasons Air Conditioning and Heating 966880 Clear 15 Insured On file
Aveo INC 969881 Clear 14 Insured On file
Climate Specialists 1003654 Clear 11 Insured On file
Managa Raul Manuel 1005647 Clear 11 Insured On file
Ciel Air Conditioning and Electric 1039457 Clear 8 Insured On file
H J R Contracting INC 1041548 Clear 8 Insured On file
L B Air Conditioning 1072480 Clear 5 Insured On file
Thlc Corporation 1077041 Clear 5 Insured On file
Yq Air Condition Solution 1077548 Clear 5 Insured On file
High Noon Air 1085441 Clear 4 Insured On file
Yuze Air Conditioning 1086305 Clear 4 Insured On file
Allwayz Heating & Air Conditioning INC 1097372 Clear 4 Insured On file
Honest Pro Air Conditioning and Heating 1106190 Clear 3 Insured On file
Wu Chung Chieh 1105504 Clear 3 Insured On file
Zhuoxin Construction 1116182 Clear 2 Insured On file
Lanyi USA INC 1121762 Clear 2 Insured On file
Zy HVAC Equipment Services 1133374 Clear 1 Insured On file
AC Heat Diamond Bar 1145762 Clear 1 Insured On file
Airpropower 1150732 Clear <1 Insured On file
Plhk HVAC INC 1151997 Clear <1 Insured On file
Jh Advanced HVAC Solutions 1163754 Clear <1 Insured On file
Medrara HVAC 1042958 Susp: contractor's bond 8 Insured 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 HVAC contractors are in Diamond Bar?

CSLB's current public file lists 34 HVAC contractors with a Diamond Bar mailing address. 33 have a Clear status, and 94.1% show no issues at all in the file (no suspension, no pending action, bond on file, not near expiration).

What license does a HVAC contractor need in California?

CSLB issues the C-20 Warm-Air Heating, Ventilating and Air-Conditioning Contractor classification for this work. In Los Angeles County, 97.1% 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 HVAC contractor's workers' comp?

Open the contractor's profile here to see the workers' comp type and insurer from CSLB's file. In Diamond Bar, 100% of HVAC contractors list a policy, 0% claim an exemption and 0% show no current coverage. Confirm the policy with CSLB's workers' comp search before work starts. How to check workers' comp.

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