| A & A Quick Cooling Inc | C20 | 1995 | Active |
| A - 1 Service Appliances Inc | C20 | 2008 | Renew by Nov 30, 2026 |
| A / C Control Inc | C20 | 2004 | Active |
| A C E Care Inc | C20 + B, C10 | 2004 | Active |
| A E HVAC & Electrical Inc | C20 + C10 | 2023 | Active |
| A/C Geeks Heating & Cooling Inc | C20 | 2017 | Active |
| Above Construction Group | C20 + B | 2020 | Active |
| AC Masters Inc | C20 + C2 | 2019 | Active |
| Aeris M E P | C20 | 2023 | Active |
| Aerodynamix HVAC Inc | C20 | 2002 | Active |
| Affordable Fire Services | C20 + C10, C16, C36 +1 | 2016 | Active |
| Air Kool Inc | C20 | 1989 | Active |
| Air One Heating & Cooling Inc | C20 | 2025 | Active |
| Air Pro La Inc | C20, C38 + C10 | 2024 | Active |
| Air Quality Pros USA Inc | C20 | 2024 | Active |
| Air Quality Solutions HVAC | C20 | 2026 | Active |
| Air-Al | C20 + B | 2021 | Active |
| Airlex Inc | C20 | 2019 | Active |
| Airtek Pros Air Conditioning & Heating Inc | C20 | 2023 | Active |
| All Area Services | C4 + B, C16, C36 +1 | 2007 | Active |
| All Future Construction LLC | C20 + B, C10, C36 | 2005 | Active |
| All Temp Systems Inc | C20 | 2013 | Active |
| Amazing Airconditioning Inc | C20 + C10, C36, C46 | 2005 | Active |
| Amgreen Buiders Inc | C20 + B, C10, C36 | 2018 | Active |
| Amgreen Solar Electric | C20 + B, C10, C36 | 2013 | Active |
| Amgreen Solutions Inc | C20 + B, C10, C36 | 2010 | Active |
| Ankor Associates Inc | C20 + A, B, C10 +4 | 2014 | Active |
| Appletree Corporation The | C20, C38 | 1992 | Renew by Dec 31, 2026 |
| Arie Plumbing | C20 + B, C34, C36 | 1996 | Active |
| Around The Clock Heating & A/C | C20, C38 | 1992 | Active |
| Atlantic Builders Inc | C20 + B, C10, C36 | 2001 | Active |
| Aurora HVAC Inc | C20 | 2022 | Renew by Dec 31, 2026 |
| Avm HVAC Contractors Inc | C20 | 2026 | Active |
| B & M Air And Heating Inc | C20 | 2015 | Active |
| B & S Construction Inc | C20 + B, C10, C33 +1 | 2004 | Active |
| B D S Sheetmetal & Airconditioning Inc | C20 + C43 | 1985 | Active |
| Barunson Construction Inc | C20 + B, C36 | 2020 | Active |
| Bateman Water Heating Engineering Inc | C4 + C10, C36, HAZ | 1992 | Active |
| Bautista Refrigeration | C38 | 2025 | Active |
| Best Pro Air Conditioning & Heating | C20 | 2025 | Active |
| Beyond Builder | C20 + B, C36 | 2024 | Active |
| Bilt-Well Roof And Material Co | C20 + B, C10, C39 +1 | 1984 | Active |
| Blizzard Air Conditioning & Heating | C20 | 2020 | Active |
| Bon Air Incorporated | C20 + B | 1986 | Active |
| Botellos Boys Heating And Air LLC | C20 | 2019 | Renew by Dec 31, 2026 |
| Brody Pennell Heating & Air Conditioning | C20 | 1969 | Active |
| Building Doctors | C20 + B | 2009 | Active |
| C D Plumbing Inc | C20 + C36 | 2016 | Active |
| Cah Heating & Cooling Inc | C20 | 2024 | Renew by Nov 30, 2026 |
| Caliber Heating & Air Conditioning Services Inc | C20 | 2017 | Active |
| California A / C | C20 | 2007 | Active |
| California Heating & Air Conditioning | C20 | 2008 | Active |
| California Heating & Air Inc | C20 | 2022 | Renew by Dec 31, 2026 |
| Cdy-Hvac Inc | C20 + C10 | 2018 | Renew by Dec 31, 2026 |
| China Pacific Inc | C20, C38 + B, C10, C36 +1 | 1987 | Active |
| Climate Solutions HVAC | C20, C38 | 2023 | Active |
| Climatech Inc | C20 | 2021 | Active |
| Coastal Climate Co LLC | C20 | 2026 | Active |
| Cold Pro Refrigeration LLC | C38 | 2026 | Active |
| Cool Air California Heating & Cooling Inc | C20 | 2025 | Active |
| Coolmart Group Inc | C20 | 2008 | Active |
| Designer Engineering & Contracting Inc | C4 + A, B | 2000 | Active |
| Dryer Vent Wizard | C20 | 2024 | Active |
| Dual Temp Refrigeration | C38 | 2025 | Active |
| East Design Construction Inc | C20 + B, C36 | 2020 | Active |
| Efficient Aire Mechanical Inc | C20 | 2018 | Active |
| Eskimo Air Control & Construction Inc | C20, C38 + B, C10 | 2006 | Active |
| Evergreen Construction | C20 + B, C36 | 2018 | Active |
| Fire Pumps R US | C20 + C10, C16, C36 | 2004 | Active |
| Fivestars Construction | C20 + B | 2016 | Active |
| Flo Heating & Air Inc | C20 + B, C36 | 2025 | Active |
| FMG HVAC Inc | C20 | 2020 | Active |
| Fondas Electric Inc | C20 + C10, C46 | 1987 | Active |
| Forever Cool Refrigeration Inc | C20, C38 | 2011 | Active |
| Frigus Mechanical LLC | C20 | 2026 | Active |
| Fulfilled HVAC And Electrical | C20 + C10 | 2017 | Active |
| G E Engineering Inc | C20 + A, B | 2013 | Active |
| Ga Ju Cooling Systems | C20 + B | 2022 | Active |
| Gama Central Heating & Air Conditioning | C20, C38 | 1983 | Active |
| Gaona HVAC Inc | C20 + C10 | 2024 | Active |
| GBS Company | C20 + B, C10, C16 +2 | 2009 | Active |
| Glacial HVAC Pro Inc | C20 | 2018 | Renew by Dec 31, 2026 |
| Global Seasons HVAC | C20 | 2018 | Active |
| Gold Coast Climate Control | C20 | 2026 | Active |
| Golden HVAC Design Inc | C20 | 2021 | Active |
| Grand Heating And Air Conditioning | C20 | 1977 | Active |
| Green Air HVAC Inc | C20 | 2017 | Active |
| Green Planet H.V.A.C | C20 | 2025 | Active |
| Heflin & E Paul Plumbing Inc | C20 + C36 | 1961 | Active |
| Home Upgrade Specialist Inc | C20 | 2017 | Active |
| HVAC Jesca Inc | C20 | 2024 | Active |
| HVAC Solutions LLC | C20 | 2021 | Renew by Nov 30, 2026 |
| I - Tech Mechancial Contractor Inc | C20 | 2011 | Active |
| Integrity Air Inc | C20 | 2026 | Active |
| International Developers And Engineering Group | C20 + B, C10 | 2012 | Active |
| J L Sheetmetal Inc | C20 + C43 | 2008 | Active |
| J Z Air Inc | C20 | 2008 | Active |
| JDS Heating And Air | C20 | 2022 | Active |
| Jna Heating & Cooling | C20 | 2022 | Active |
| Jo-Mi Plumbing & Solar Inc | C20 + C36, C46 | 1966 | Active |