Over A Century of Quality Service, Repair & Innovative Installation In 1906, Oren Charles McDonald founded O.C. McDonald Company in San Jose, California. From the outset, O.C. McDonald was one of the foremost plumbing, process piping and HVAC service providers in the Bay Area, installing the first air conditioning system in the city. Since our inception, O.C. McDonald Company has some of the most complicated installations in the valley under our belt. Over a century later, the founder's great grandson, Jim McDonald, has upheld the utmost level of quality workmanship, traditional values and technical innovation upon which O.C. McDonald was established. We Believe in exceptional customer service, unwavering quality, absolute reliability, and continual innovation, on time and on budget. You can depend upon O.C. McDonald for all of your plumbing and HVAC service, repair and installation needs.