O.C. McDonald
Company Overview
Discover what we can offer!
O.C. McDonald Company has stood as the Bay Area's premier Mechanical Contractor for over a hundred years, focusing on HVAC, plumbing, process piping, building services, direct digital control systems, and building automation. Our services extend across various industries, such as LEED Certified projects, data centers, high-tech clean room construction, process tool installation, heavy industrial piping, commercial, institutional, healthcare, and hospitality. Additionally, O.C. McDonald utilizes its extensive experience to provide the right solutions for building owners and managers aiming for effective building management. Mechanical Contractor, Piping Contractor, Plumbing Contractor, HVAC Contractor, Heating Contractor, LEED Certified, Sheet Metal Fabrication, Service and Repair, Maintenance.
O.C. McDonald Company has been a top choice for plumbing, process piping, and HVAC services in the Bay Area for over a century, making it the oldest company of its kind in Silicon Valley. Founded by Oren Charles McDonald in 1906, the company is now owned and operated 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. 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

My wife and I have been using O C McDonald for at least the last 15 years, but a recent experience reminded me of how responsive, concerned and professional the company and their team are. Last Thursday our gardener called my attention to a spot next to our water meter where the water was bubbling up out of the ground and pouring out onto the lawn. Called the SJ Water Company who came out Friday morning and informed me that we had a very bad leak and that he was turning off the water to our house immediately. And that the leak was our responsibility - not that of the water company. :-(
In somewhat of a panic (no water all weekend?!?!) I called O C McDonald and they had James out that afternoon. He isolated the leak, replaced the broken pipes and was able to turn the water back on to our house in time for us to have water to cook dinner.
Great company, great team - you don't need to look any further than these people for your plumbing needs! :-)

Hired them to fix problems with our 1940's floor heaters. They came out the next day for an estimate. James our tech, arrived at the scheduled time and even called 10 min. before his arrival. What a concept lol. He gave us several options, some that they weren't able to do, so that was nice. James was very professional, knowledgeable, and a pleasure to work with. Problems solved and would hire them again. The reason for 4 stars is that the estimate ($129) wouldn't be applied to the cost of repairs if we decided to go with them. Still reasonable though. Was expecting to pay more.

I had to get a 40-gallon water heater replaced and had my home warranty plumber come out to give me an estimate. They said tops $700 for labor (not including the water heater) and a friend suggested OCM. I should have asked for an estimate before because if I knew before hand what it would cost, I would not have used them, but instead I trusted that they would be fair. Instead a month later I receive a bill that is at least 2 times the cost for the install. I spoke with their billing department and they could not see that they were grossly overcharging for labor. Worst than lawyers. To be fair, the quality of work was very good so if you want to pay twice the price, be my guest.

We've used O.C. McDonald for years for all of our serious plumbing problems...I say ""serious"" because they are so popular they are always busy and sometimes one just has to get something done right away by ""the other guys"". I did that the other day and was really disappointed; the problem was un-fixed and the reason not well-explained. I called scheduling at OCM and got Debbie, who, in spite of their usual full schedule, was able to schedule me with master plumber, Jason, who appear at my door the next morning, very early in my assigned time slot. Jason inspired confidence with his impressive knowledge bank, his ability to communicate, his deductive ability and his step-wise work. Fixed the problem, explained it well, cleaned-up thoroughly and all for a reasonable price! Did I say I'm a fan?

Great customer service! No hidden fees/prices
This company has been around for over 100 years! Place is pretty old and they are a union shop! So that means their services will be much more than normal places.
The sheet metal shop is open from 7-3pm M-F

I had problems with a toilet for 6 months. Two licensed guys could do nothing but replace wax ring. ""Don"" came out and went the extra mile to pull toilet, put it up on saw horse and test the bowl. Sure enough he discovered manufacturing defect that occurs 1/100.
The guy was good, nice and clean. Can't ask for better. Fair price.

Old school service. I had an oddball request and they weren't able to help me out but the girl on the phone had a couple of great leads and went out of her way to make sure that she did everything possible to make sure I was helped, even though it was obvious that I wasn't going to be spending any money there. I felt like it needed to be mentioned.

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.