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Licensed HVAC contractors in Diamond Bar
32 contractors with a Diamond Bar mailing address hold an active (CLEAR) CSLB C-20 Warm-Air Heating, Ventilating and Air-Conditioning (HVAC) license in CSLB's license file dated Oct 20, 2026. 32 of them show a workers' comp policy on file. Get quotes from up to 3 of them →
Heating and air conditioning work calls for a C-20 license. CSLB requires C-20 licensees to carry workers' compensation even if they have no employees, so check that a policy is on file.
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A Featured spot on this hvac page for Diamond Bar is a paid ad for a License Verified contractor, labeled "Ad" every time. It sits apart from the directory and never changes the order below. From $49/mo. Join the waitlist →
All 32 licensed HVAC contractors
Order: A–Z by business name (neutral, stated). Showing 1–32. AC HEAT DIAMOND BAR
C-20 · Lic. #1145762 · Diamond Bar 91765
Workers' comp policy on file
✓License Verified CSLB file · Oct 20, 2026
ACE RODIL HEATING AND AIR CONDITIONING
C-20 · Lic. #631042 · Diamond Bar 91765
Workers' comp policy on file
✓License Verified CSLB file · Oct 20, 2026
AIRPROPOWER
C-20 · also C-10 · Lic. #1150732 · Diamond Bar 91765
Workers' comp policy on file
✓License Verified CSLB file · Oct 20, 2026
ALLWAYZ HEATING & AIR CONDITIONING INC
C-20 · Lic. #1097372 · Diamond Bar 91765
Workers' comp policy on file
✓License Verified CSLB file · Oct 20, 2026
ATLANTIC AIR CONDITIONING INC
C-20 · Lic. #613226 · Diamond Bar 91765
Workers' comp policy on file
✓License Verified CSLB file · Oct 20, 2026
AVEO INC
C-20 · also A, B, C-10, C-36 · Lic. #969881 · Diamond Bar 91765
Workers' comp policy on file
Active — CSLB flag: workers' comp suspension pending
C S D M INC DBA CAL STEAM COMPANY
C-20 · also C-4, C-36 · Lic. #674646 · Diamond Bar 91765
Workers' comp policy on file
✓License Verified CSLB file · Oct 20, 2026
CHUNG CHIEH WU
C-20 · Lic. #1105504 · Diamond Bar 91765
Workers' comp policy on file
✓License Verified CSLB file · Oct 20, 2026
CIEL AIR CONDITIONING AND ELECTRIC
C-20 · also C-10 · Lic. #1039457 · Diamond Bar 91765
Workers' comp policy on file
✓License Verified CSLB file · Oct 20, 2026
CLIMATE SPECIALISTS
C-20 · Lic. #1003654 · Diamond Bar 91765
Workers' comp policy on file
✓License Verified CSLB file · Oct 20, 2026
FOUR SEASONS AIR CONDITIONING AND HEATING
C-20 · Lic. #966880 · Diamond Bar 91765
Workers' comp policy on file
✓License Verified CSLB file · Oct 20, 2026
GARY'S AC SERVICES
C-20 · Lic. #921063 · Diamond Bar 91765
Workers' comp policy on file
Active — CSLB flag: workers' comp suspension pending
GREEN AIR & REFRIGERATION
C-20 · also C-38 · Lic. #839148 · Diamond Bar 91765
Workers' comp policy on file
✓License Verified CSLB file · Oct 20, 2026
HIGH NOON AIR
C-20 · also C-38 · Lic. #1085441 · Diamond Bar 91765
Workers' comp policy on file
✓License Verified CSLB file · Oct 20, 2026
HJR CONTRACTING INC
C-20 · also B · Lic. #1041548 · Diamond Bar 91765
Workers' comp policy on file
✓License Verified CSLB file · Oct 20, 2026
HONEST PRO AIR CONDITIONING AND HEATING
C-20 · Lic. #1106190 · Diamond Bar 91765
Workers' comp policy on file
✓License Verified CSLB file · Oct 20, 2026
KENNETH DALEY HEATING & AIR SERVICES
C-20 · also C-36 · Lic. #798187 · Diamond Bar 91765
Workers' comp policy on file
Active — CSLB flag: workers' comp suspension pending
L B AIR CONDITIONING
C-20 · Lic. #1072480 · Diamond Bar 91765
Workers' comp policy on file
✓License Verified CSLB file · Oct 20, 2026
LANYI USA INC
C-20 · Lic. #1121762 · Diamond Bar 91765
Workers' comp policy on file
✓License Verified CSLB file · Oct 20, 2026
LIKAI CHEN HVAC INC
C-20 · Lic. #926434 · Diamond Bar 91765
Workers' comp policy on file
✓License Verified CSLB file · Oct 20, 2026
MAC REFRIGERATION AND AIR CONDITIONING CO
C-20 · Lic. #580557 · Diamond Bar 91765
Workers' comp policy on file
✓License Verified CSLB file · Oct 20, 2026
MCMASTER MECHANICAL
C-20 · Lic. #879152 · Diamond Bar 91765
Workers' comp policy on file
✓License Verified CSLB file · Oct 20, 2026
MR A/C
C-20 · Lic. #864636 · Diamond Bar 91765
Workers' comp policy on file
✓License Verified CSLB file · Oct 20, 2026
PLHK HVAC INC
C-20 · Lic. #1151997 · Diamond Bar 91765
Workers' comp policy on file
✓License Verified CSLB file · Oct 20, 2026
RAUL MANUEL MAGANA
C-20 · also B · Lic. #1005647 · Diamond Bar 91765
Workers' comp policy on file
✓License Verified CSLB file · Oct 20, 2026
SERVICE WIZARDS
C-20 · also C-36, C-42 · Lic. #797071 · Diamond Bar 91765
Workers' comp policy on file
✓License Verified CSLB file · Oct 20, 2026
THLC CORPORATION
C-20 · also B, C-10, C-36, C-38 · Lic. #1077041 · Diamond Bar 91765
Workers' comp policy on file
✓License Verified CSLB file · Oct 20, 2026
YQ AIR CONDITION SOLUTION
C-20 · Lic. #1077548 · Diamond Bar 91765
Workers' comp policy on file
✓License Verified CSLB file · Oct 20, 2026
YUZE AIR CONDITIONING
C-20 · Lic. #1086305 · Diamond Bar 91765
Workers' comp policy on file
✓License Verified CSLB file · Oct 20, 2026
ZHUOXIN CONSTRUCTION
C-20 · also B, C-10 · Lic. #1116182 · Diamond Bar 91765
Workers' comp policy on file
✓License Verified CSLB file · Oct 20, 2026
ZIP RENOVATION & AIR
C-20 · also B, C-10, C-15, C-36 · Lic. #762505 · Diamond Bar 91765
Workers' comp policy on file
✓License Verified CSLB file · Oct 20, 2026
ZY HVAC EQUIPMENT SERVICES
C-20 · Lic. #1133374 · Diamond Bar 91789
Workers' comp policy on file
✓License Verified CSLB file · Oct 20, 2026