| 1 Haro 1 LLC | C20 | 2023 | Active |
| 1 Hour Drain Hotshot Restoration | C20 + B, C36, C43 +1 | 2010 | Active |
| 1153 San Rafael LLC | C20 + B | 2019 | Active |
| 2020 Heating & Air Inc | C20 | 2022 | Active |
| 72 Degrees | C20 + C43 | 2006 | Active |
| 72 Infinity Heating & Air Inc | C20 | 2017 | Active |
| A & H Heating & Air Conditioning Service Inc | C20 | 1975 | Active |
| A - 1 Heating And Cooling Inc | C20 | 2011 | Active |
| A Plus Commercial Services | C20 + B, C36 | 2005 | Active |
| Aaa Furnace And Air Conditioning Co | C20 | 1999 | Active |
| Air Care Heating & Cooling Inc | C20 | 2013 | Active |
| Air Hero Heating And Air Conditioning Inc | C20 | 2026 | Active |
| Air Sharks LLC | C20 | 2023 | Active |
| Air Systems Inc | C20 + C10, C36, C43 +1 | 2005 | Active |
| Air- Works Heating & Cooling | C20 | 2026 | Active |
| Air-N-Tech Inc | C20 | 2024 | Active |
| Aireserv Of Campbell And Saratoga | C20 | 2023 | Active |
| Airpro HVAC | C20 | 2023 | Active |
| Airseco Mechanical Inc | C20 + B, D62 | 2000 | Active |
| Airtify Heating And Air Conditioning | C20 | 2019 | Active |
| Alb Construction | C20 + B, C10, C36 | 2025 | Active |
| Albos HVAC | C20 | 2026 | Active |
| All American Heating And Cooling Inc | C20 | 2026 | Active |
| All Bay Refrigeration Services Inc | C38 | 2023 | Active |
| Alldon Construction Inc | C20 + B, C10 | 2020 | Active |
| Allied Construction Builders Inc | C20 + B, C10 | 2011 | Active |
| Alpha HVAC & Electrical | C20 + C2, C10 | 2019 | Active |
| American Beverage Equipment Inc | C38 + C36 | 1994 | Active |
| American Builder & Electrical Inc | C20 + A, B, C10 +1 | 2021 | Active |
| Americool Comfort | C20 | 2026 | Active |
| Antom Construction Inc | C20 + B, C10 | 2021 | Active |
| Aqua Heating Systems Inc | C4 | 1994 | Active |
| Arctic HVAC Repair | C20 | 2022 | Active |
| Astro Heating Inc | C20 | 2025 | Active |
| Atrics Inc | C20 + B, C15, C17 +2 | 2010 | Active |
| Ats Mechanical | C4, C20, C38 + B, C36 | 1984 | Active |
| Attic Crew | C20 + B, C2 | 2017 | Active |
| Automated Building Control Solutions | C20 + C7 | 2013 | Active |
| Automated Solutions Group Inc | C20 | 2012 | Renew by Dec 31, 2026 |
| Axis Mechanical Inc | C20 + C36 | 2012 | Active |
| Ay Emp Inc | C20 + B, C10, C36 | 2021 | Active |
| Az Refrigeration | C38 | 2026 | Active |
| B A Z Service Refrigeration Inc | C38 | 2008 | Active |
| B M J US Builder Inc | C20 + B | 2007 | Active |
| Bay Cooling Solutions Inc | C20 | 2019 | Active |
| Bolanos Heating And Air Conditioning | C20 | 2024 | Active |
| Brilliant General Maintenance Inc | C20 + B, C27 | 2010 | Active |
| Bukazoo Inc | C20 + B, C36 | 2015 | Active |
| C & J Contracting Inc | C20 + B, C33 | 1984 | Renew by Dec 31, 2026 |
| Cal Bay Mechanical Inc | C20 | 2018 | Active |
| Calvey Heating & Air | C20 | 2009 | Active |
| Cascade Refrigeration Service & Repair LLC | C20, C38 | 2009 | Renew by Dec 31, 2026 |
| Castrillo Heating & Air Conditioning Corp | C20 | 2009 | Active |
| Cazafria Air Inc | C20 | 2026 | Active |
| Cellarcraft Climate Systems LLC | C20, C38 | 2022 | Active |
| Chuong HVAC Inc | C20 | 2018 | Active |
| Ciari Stephen Plumbing And Heating Inc | C4, C20 + C36 | 2003 | Active |
| Cic Enterprises LLC | C20 | 2026 | Active |
| Clean Air Company Inc | C20 | 2026 | Active |
| Clean Tech Builders | C20 + B, C10, C36 | 2016 | Active |
| CN Electric Power Inc | C20 + B, C10 | 2018 | Active |
| Comfort Air HVAC Inc | C20 | 2020 | Renew by Dec 31, 2026 |
| Comfort Eco A/C Inc | C20 | 2020 | Active |
| Comfort International Inc | C4, C20, C38 + B, C10 | 1999 | Active |
| Cool Guys Mechanical Inc | C20 | 2015 | Active |
| Cozy House Forever Corporation | C20 + C10 | 2024 | Active |
| Cpi Service | C20 + A, C36 | 2023 | Active |
| Critchfield Mechanical Inc | C4, C20 + C36 | 1977 | Active |
| D G Heating And Air Conditioning Inc | C20 + C10, C46 | 2018 | Active |
| Daas Heating & Cooling Inc | C20 | 2019 | Active |
| De HVAC Inc | C20 | 2026 | Active |
| Delta Emc Inc | C20 + C10, C16 | 2001 | Active |
| Design Heating & Air Conditioning Inc | C20 | 2010 | Active |
| Duran HVAC Inc | C20 | 2019 | Active |
| Ecs Design Inc | C20 + B, C10 | 1998 | Active |
| Eddies Home Care Services Inc_dba Elos Air | C20 | 2023 | Active |
| Ehsan HVAC Inc | C20 | 2018 | Active |
| Eligius Manufacturing Inc | C38 + B, C51, C60 | 2022 | Active |
| Essential Plumbing Service And Maintenance Inc | C4, C20 + C16, C36, C42 | 2024 | Active |
| Euro Climate Inc | C20 + C36 | 2012 | Active |
| Everest Heating And Cooling Inc | C20 | 2025 | Active |
| Freon Inc | C20 + C10 | 2023 | Active |
| Fresh Air Construction Inc | C20 + B | 2006 | Active |
| Future Air | C20 | 1989 | Active |
| GLD Green Energy | C20 + B, C10, C36 | 2006 | Active |
| Gonzalez Heating & Air Inc | C20 | 2022 | Active |
| Green HVAC LLC | C20 | 2024 | Renew by Nov 30, 2026 |
| Green Planet Heatng & Cooling Inc | C20 | 2015 | Active |
| H & H Heating And Air Conditioning Services Inc | C20 | 2007 | Active |
| H H Heating And Air Conditioning | C20 | 2022 | Active |
| Haxx Heating, Air & Electrical | C20 + C10 | 2021 | Active |
| Heating Cooling & Appliance Technique Inc | C20, C38 | 2010 | Active |
| Hickey W L Sons Inc | C4, C20 + C16, C36, C42 | 1947 | Active |
| HP HVAC Inc | C20 | 2018 | Active |
| HVAC Bay Services Inc | C20 | 2025 | Active |
| HVAC Dome Inc | C20 | 2023 | Active |
| HVAC Guru | C20 + C2 | 2017 | Active |
| Hvacerz | C20 | 2020 | Active |
| I D C Engineering | C20, C38 + A, C10, C36 +1 | 1998 | Active |
| Icom Mechanical Inc | C20 + B, C36 | 1981 | Active |