Serving Silicon Valley and the Bay Area since 1906


Whether you need to repair, replace, upgrade or maintain your heating and air conditioning system, O.C.McDonald has done it. In fact, we’ve done it for over 100 years.
Our certified technicians can service most brands of HVAC and we partner with industry leaders to offer the highest quality equipment at the best possible price. With a combination like that, we’re sure to get the job done—and done right.

Our expertise goes beyond air conditioning. O.C.McDonald technicians can assist you with wall heaters, water heaters. direct vent or radiant heating, exhaust fans, humidifiers and more. Consider us a one-stop-shop for your heating and cooling needs.

We help save you money before any work begins so you know exactly what it costs and what’s going to be done. We like to think of it as a “no surprises approach.” Call us today for a free estimate or for more information! We accept major credit cards and have financing available.

comprehensive design



new construction

Sheet Metal Fabrication

HVAC & Plumbing


We serve all of Silicon Valley

O.C.McDonald is a family-owned company that has been resolving plumbing issues for over 100 years. With our experience and values, we don’t stop until your plumbing problem is resolved.
Our plumbers complete a thorough examination and will dedicate their time to helping you better understand the problem and the proper procedure to fix it. It’s our goal to meet your expectations. Better yet, we’ll let you know what to expect before you open the bill. Contact us today for a free estimate or to obtain more information on our plumbing services. We accept major credit cards and have financing available.

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