| Indoor Air Design Inc | C20 | 1985 | Active |
| Innovation Heating & Air Inc | C20 + D38 | 2022 | Active |
| Interstate Decisive Contractor-I D C | C20 + A, B, C10 +5 | 1982 | Active |
| Irbis Air Plumbing Electrical | C20 + C10, C36 | 2018 | Active |
| J & J Air Conditioning Inc | C20, C38 + C36 | 1980 | Active |
| J A Mechanical | C20 | 2001 | Active |
| JBBC Heating And Air Conditioning Inc | C20 | 2024 | Active |
| JC Heating And Cooling Inc | C20, C38 + C10 | 2022 | Active |
| JH Heating & Cooling Inc | C20 | 2020 | Active |
| Jking HVAC Inc | C20 | 2025 | Active |
| Jla Heating And Air Conditioning LLC | C20 | 2021 | Active |
| JMM Construction LLC | C20 + B | 1993 | Active |
| JMS Heating & Air Conditioning Inc | C20 | 2020 | Active |
| K S HVAC Inc | C20 | 2015 | Active |
| Kailey Air Systems | C20, C38 + C10 | 2022 | Active |
| Le H V A C The | C20 | 2017 | Active |
| Leader Design & Construction Corp | C20 + B, C10, C36 | 2011 | Active |
| LL Heating And Air Conditioning | C20 | 2024 | Active |
| Lorenzo Heating & Cooling | C20 | 2023 | Active |
| Lowe's Air Duct Cleaning | C20 + D64 | 2020 | Active |
| M & M HVAC Maintenance & Mechanical Inc | C20 | 2021 | Active |
| Majestic Heating And Air Conditioning | C20 | 2024 | Active |
| Martcor Heating & Air Inc | C20 | 2026 | Active |
| Martinico And Sons Inc | C20 + C43 | 1956 | Active |
| Master Maintenance Home Services Inc | C20 | 2025 | Active |
| Maverick Mechanical LLC | C38 | 2020 | Active |
| MC Donald O C Co Inc | C4, C20 + A, B, C36 +2 | 1958 | Active |
| MDP Heating & Cooling Inc | C20 | 2023 | Active |
| Millennium Pacific Trading Inc | C4 + B | 2009 | Active |
| MQ Mechanical Inc | C20, C38 + B, C10 | 2026 | Active |
| Mr Reliable Plumbing & Heating | C20 + C36 | 2016 | Active |
| N T Bay Area Construction Inc | C20 + B, C36 | 2018 | Active |
| Norcal Bay Construction Inc | C20 + B, C36 | 2019 | Active |
| Ozone HVAC | C20 + C10 | 2024 | Active |
| P And L Sheetmetal | C20 + B, C43 | 2002 | Active |
| P C M Heating And Air Conditioning Inc | C20 | 1991 | Active |
| Pab Solar And Air Inc | C20 + C46 | 2005 | Active |
| Pacific Coast Balancing Inc | C20 + D62 | 2004 | Active |
| Pacific Coast Home Services | C20 + B, C10, C27 +1 | 2005 | Active |
| Pacific Cooling And Calibrations | C20 | 2009 | Active |
| Powerful Air Condition Inc | C20 | 2023 | Active |
| Precision Heating And Cooling Inc | C20 | 2019 | Active |
| Premier Climate Control LLC | C20 | 2024 | Active |
| Pure Air Solutions | C20 | 2024 | Active |
| Qualtech Mechanical Inc | C20 + B, C36 | 2016 | Renew by Dec 31, 2026 |
| R & R Refrigeration & Air Conditioning Inc | C38 | 1993 | Active |
| Ream's Mechanical HVAC Service | C20 | 2026 | Active |
| Rescue Air Service Inc | C20 | 2003 | Active |
| Resilience Air | C20 | 2026 | Active |
| Rittinger Heating & Air LLC | C20 | 2025 | Active |
| Rocha's Company Inc | C20 + B | 2003 | Active |
| Rodriguez Sheet Metal | C20 + C43 | 2013 | Active |
| Sae Consulting Engineering | C20 + A, B, C8 +1 | 2013 | Active |
| San Jose Air & Heating | C20 | 2025 | Active |
| San Jose Boiler Works Inc | C4 | 1975 | Active |
| Sav Water Heaters And Plumbing | C20 + C10, C36 | 2023 | Active |
| Schaper Construction Inc | C20 + A, B, C10 +2 | 1991 | Active |
| Seabright Heating & Cooling Inc | C20 | 2025 | Active |
| Seton Pacific Company | C20 + B, C10, C16 +1 | 2010 | Active |
| Shadow Fire Protection Inc | C20 + C16, D34 | 2009 | Active |
| Silicon Valley Heating And Air Inc | C20 | 2025 | Active |
| Silicon Valley Mechanical Inc | C4, C20 + C36 | 2014 | Active |
| South Bay Air LLC | C20 | 2014 | Active |
| Square Three Inc | C20 + B, C10, C16 +2 | 2021 | Active |
| Steinke Advanced Mechanical Systems Inc | C4 | 2009 | Active |
| Supreme Comfort H V A C Inc | C20 + C10, C43 | 2006 | Active |
| SVS Home Comfort | C20 | 2019 | Active |
| T C T Heating & Cooling Inc | C20 | 2014 | Active |
| T T Construction Inc | C20 + B, C10, C36 | 2019 | Active |
| Tempro LLC | C20 + B | 2021 | Active |
| Therma LLC | C4, C20, C38 + A, B, C10 +2 | 2017 | Active |
| Therma Tech Inc | C20 | 2008 | Active |
| Thermal Precision | C38 | 2024 | Active |
| TN Construction And HVAC | C20 + B | 2025 | Active |
| Trio Heating Air Plumbing & Electrical | C20 + B, C10, C36 | 2019 | Active |
| True Good Energy Builds Inc | C20 + B, C10, C17 +1 | 2026 | Active |
| United Mechanical | C4, C20, C38 + B, C36, C43 | 2003 | Active |
| Valley Heating,cooling,electrical And Solar | C4, C20, C38 + C10 | 1969 | Renew by Dec 31, 2026 |
| Weise Mechanical LLC | C20 | 2020 | Active |
| West Coast Mechanical | C20 | 2016 | Active |
| Westview Heating And Cooling Inc | C20 | 2017 | Active |
| Yosh Enterprises | C20 + B, C10, C36 | 2006 | Active |