O.C. McDonald
Company Overview
Discover what we can offer!
For more than a century, O.C. McDonald Company has been the Bay Area's trusted Mechanical Contractor, specializing in HVAC, plumbing, process piping, building services, direct digital control systems, and building automation. We serve multiple sectors, including LEED Certified projects, data centers, high-tech clean room construction, process tool installation, heavy industrial piping, commercial, institutional, healthcare, and hospitality. Moreover, O.C. McDonald draws on its vast experience to equip building owners and managers with the tools needed for efficient building management. HVAC Contractor, Plumbing Contractor, Mechanical Contractor, Piping Contractor, Heating Contractor, LEED Certified, Sheet Metal Fabrication, Service and Repair, Maintenance.
For more than a hundred years, O.C. McDonald Company has been a leading provider of plumbing, process piping, and HVAC services in the Bay Area, establishing itself as the oldest such company in Silicon Valley. Established in 1906 by Oren Charles McDonald, the company is currently led by Jim McDonald, the great-grandson of the founder. We are recognized for delivering high-quality workmanship and have executed some of the most challenging installations in the valley. We have built our reputation on the fusion of classic values and innovative technology; together, they provide our clients with reliable quality, excellent customer service, and a contractor who respects deadlines and budgets.
Business Services
- Bathtub repair
- Drain repair
- Faucet installation
- Faucet repair
- Garbage disposal installation
- Gas line installation
- Gas line repair
- HVAC installation or replacement
- HVAC system repair
- HVAC system maintenance
- Plumbing inspection
- Plumbing installation or replacement
- Plumbing repair
- Sewer installation
- Sewer repair
- Shower repair
- Toilet installation
- Toilet repair
- Water heater installation
- Water heater repair
Business Location & Hours
Mon: | Open 24 hours |
Tue: | Open 24 hours |
Wed: | Open 24 hours |
Thu: | Open 24 hours |
Fri: | Open 24 hours |
Sat: | Open 24 hours |
Sun: | Open 24 hours |
Recommended Customer Reviews

Our Old floor heater stopped working so we call another company. The other company said they could not fix it and we needed a new system! My wife went down to OC Mcdonalds and talked to Ron. Ron Said no problem and set up an appointment. A gentlemen named James came to our house and spent 5 hours rebuilding our old 1934 heater and It works great!!!!! James was a very quiet hard working young gentleman. We really appreciate such super service and cannot say enough about James!!!! I would recommend this company to anyone.

Used O,C Mcdonald for the first time at our company today , We had a plumbing company we have used for years but after not be able to get anyone out here we called O.C McDonald to help with moving some pipes for a small office remodel we are doing .
Daniel was very helpful he was able within minutes to locate a shut off that we were unable to locate,he was very efficient and able to explain to me exactly what needed to be done and he complete it very fast, so we could complete on time.
Great Pricing
Customer service in the office was great ( Debbie)
Fast & Efficient
Will definitely be recommending to others !

Since Jan. I have contacted several plumbers to diagnose a problem. After months of getting no where, O.C. Mcdonald was recommended to me. One phone call and next day service fixed a situation that others found puzzling. Cheers to William and Smilin Steve for putting their heads together and finding the cause of my leaking pipe. These two are an amazing team. Besides being very knowledgable, their humor and work ethic is a gift.

I have used O C McDonald for years and have always gotten excellent service. My latest issue ( I always have plumbing issues) was with my upstairs toilet not flushing completely. Debbie sent William over right away he diagnosed the problem and my the next day I had a new toilet that worked great. I will continue to use their service.

Daniel Voss was knowledgeable and honest. Found the problem with our toilet and fixed it quickly. The water shut-off wasn't shutting off, so he fixed that too. He also fixed our bathtub spout (which was incorrectly installed by another plumber)! I won't hesitate to call them for any other plumbing issues! Good people and reasonable prices. They know more and charge less per hour than non-union plumbers I've used in the past. They are our family plumbers now!

I have used O.C. McDonald for several years now. After a few bad experiences with other plumbing companies, I remembered that my father liked O.C. McDonald, so I turned to them and haven't looked back. Each time I've had to call them, the technician has been very nice, very professional and knew what he was doing. The job has always been done correctly and at a decent and fair price. I've never had any problems contacting the office or setting up an appointment.
My latest experience was this past weekend. I had an ""emergency"" with my toilet and wasn't going to be able to take time off work for them to come during regular business hours, nor did I think the toilet would last that long. The dispatcher contacted the technician on call who called me back within seconds. We discussed the problem and he gave me an estimated arrival time, which he met. I might add here, that not only was it a weekend, but it was Super Bowl Sunday! I hadn't realized that when I called, though in reality, I would have still needed someone to come out as the toilet float assembly was gushing water and the valve to shut the water off wouldn't shut it off completely.
Greg was my technician. He was VERY gracious for having to come out on a Super Bowl weekend. He was prompt, professional, kept me informed of what he was doing all along the way, was patient with me which I always appreciate, and he explained the pricing and explained the work he did.
And, as I said above, I've had that same experience with each of the technicians I've had.
I'll be needing my furnace replaced soon, and I know who to call.

I've used O.C. McDonald over many years, but never have I been so impressed as I was this week when I needed help with my furnace. Our old furnace was over 30 years old and finally died, and the folks from O.C. McDonald (Greg and Bill) were super helpful in diagnosing the problem and then installing a new furnace. In addition, they discovered that one of my old drain pipes (our house is 100 years old this year) had corroded to such an extent that it was leaking and dangerous. So they replaced that also and did an excellent job. It taught me a lesson that I have to keep re-learning - when you need some serious plumbing work done, go with the best and you'll be happy that you did!

We have had O.C.McDonald on many occasions for both air conditioning, heating, watr heater installation
and plumbing. Excellent job everytime and great personel.

I really think my elderly mother was taken advantage of and when she called they made her feel like she's a little old lady and didn't understand the estimate. The plumber changed a flapper in a 1950's toilet and two on/off valves under a sink. Yes, the pipes broke when he went to change the valves, so that made it take longer and slightly more complicated. But it shouldn't have been a surprise it's a house built in the 50's with galvanized pipes. However, the first plumber who came out didn't have the tool he needed to fix the broken pipes so he called another plumber to bring it to him. Why a plumber doesn't have the tools they need on the truck is beyond me, that is their job. Apparently we were charged for the first plumber to sit & do NOTHING while waiting for the other guy to get there. We have used OC McDonald for years and never had a problem until now. But I really think they took advantage of an elderly person and we will think long & hard before we call them again.

We were thinking about getting air conditioning, and decided to get estimates. After 2 totally outrageous estimates, and getting the run around on top of it, we decided to try OC McDonald. They had installed the heater 4 yrs ago. Greg came and went to work getting what he would need for the estimate. The heater is in the attic and I knew it was going to be a harder job to accomplish since the attic is small with not alot of clearance. The estimate came back over $2000.00 less than our last one! We went with OC, Greg came with his partner Jarrod. They were awesome! The job took 2 days, they were on time, clean, knew exactly what they were doing, very nice and knowledgeable. I was so impressed! We definitely made the right choice! We are now enjoying our air conditioning and totally recommend them for any heat/air job!
Lisa B
Lisa B