Heating, Plumbing & Air Conditioning in Contra Costa County Since 1974

50 Years in Business

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NATE Certified Contractor in Contra Costa County

What is NATE? NATE stands for North American Technician Excellence, and it is the nation’s largest non-profit certification organization for HVAC contractors. NATE is the certification organization governed, owned, operated, developed and supported by the entire HVAC/R industry.

NATE certification tests represent real world working knowledge of HVAC and HVAC/R systems. Testing and exams are developed by a committee of industry experts nationwide, and represent real world HVAC/R topics pertinent to contractors and utilities alike.


Stewart Heating, Plumbing & Air Conditioning is a NATE certified Contra Costa HVAC Contractor. We offer the finest in heating, air conditioning & indoor air quality solutions for our California customers, and we’ve been serving Contra Costa County homeowners since 1974!

If you knew nothing else about Stewart Heating, Plumbing & Air Conditioning, the fact that we are a NATE certified contractor let’s you know you can trust our skills. Too many homeowners suffer from poorly installed heating, air conditioning and indoor air quality systems. Incorrectly done HVAC installations can cost substantially in lost efficiency, performance, and even premature system failure.

However, Stewart takes things beyond industry certification. The dedication to courteous, customer service that we bring to each and every job will pleasantly surprise you. We treat our customers so good, they don’t want to go anywhere else for their heating and air conditioning needs!

HVAC Repair & Maintenance

Maintaining your HVAC system is very important if you want it to run efficiently, and last as long as it was manufactured to last. A neglected heating and air conditioning system might work for you each season, but it will begin to lose efficiency, and can have premature problems, costing extra money to repair. Stewart’s seasonal maintenance plans are low cost ways to ensure your HVAC system is running at peak performance. We will clean and inspect your equipment for smooth operation.

If your indoor comfort system is not functioning correctly, our experienced technicians can help. We will quickly arrive and diagnose the problem so you experience as little down time as possible. Our extensive knowledge and experience in the HVAC field means we know how to quickly find the real problem with your system. This saves you the extra time and expense associated with lack of experience and poor troubleshooting. Once the problem is determined, we will give you our recommendations on the best action to take for your specific situation.