O.C. McDonald
Company Overview
Discover what we can offer!
With over a hundred years of experience, O.C. McDonald Company is the Bay Area's most esteemed Mechanical Contractor, excelling 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. Furthermore, O.C. McDonald applies its rich experience to deliver the right resources to building owners and managers seeking 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. Oren Charles McDonald founded the company in 1906, and today it is managed by Jim McDonald, the founder's great-grandson. We are recognized for delivering high-quality workmanship and have executed some of the most challenging installations in the valley. Our reputation stems from blending time-honored values with modern technology; this synergy guarantees our clients consistent quality, superior customer service, and a contractor who adheres to timelines 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

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

Maybe they should be called ""NO See McDonald?"" I say this because - my husband phoned them prior to the holiday. Call was not returned. He called again and explained our situation - older floor heater unit, smell of gas. The receptionist (presumably) - who I'm guessing doesn't do the repair work - said they don't recommend fixing old units and basically wrote us off. We found another company who is fixing it later this week. So, thanks for nothing, No See.

Excellent and honest!! No hidden fees. Greg Pagaling came to our home to evaluate our ancient furnace, and confirmed that a replacement was required. He did the work quickly and cleanly, and we now have a very warm home.
Another company quoted us on a much more expensive furnace, and Greg explained why that was not required in our situation. This other company also quoted us on hazardous material removal to the tune of $600 - also a cost that Greg said was not required and he explained why.
We knew we were going to have to bite the bullet and make this rather expensive purchase, but Greg made the whole thing quick and painless, and we felt confident in our decision. We got a fair price and we did not feel cheated.
We look forward to upgrading our AC with Greg next spring!!

My husband and I checked with 3 other companies when we needed a new furnace. O.C. Mc Donald was by far the best price and best customer service. I first contacted Debbie who was very pleasant and helpful. She sent Greg to install our furnace and he was very knowledgeable and had the job finished very quickly. We will be calling again in the Spring to have a new air conditioner installed. Thank you Debbie and Greg for all your help.