Peterson Mechanical
Company Overview
More than a century of dedicated service
Peterson Mechanical, a family-owned Plumbing, Heating, and Air Conditioning firm was created in Sonoma by Ed Peterson. Rich Peterson, Ed's nephew, later led the company. Today, the company is run by Rich's son, Les Peterson, along with his son, Scott, and nephew, Zach.
Our services extend throughout the North Bay Area, providing mechanical services, renovations, and new construction to various sectors including Medical Facilities, Biomedical, Manufacturing, Electronics, Offices, Schools, and Wineries. We engage in both Plan and Specification and Design Build and Design Assist projects.
Our active projects include several prominent firms in the North Coast, including Agilent Technologies, JDS Uniphase Inc., Medtronic / AVE, Kaiser Hospitals, Sutter Healthcare, St Joseph Healthcare, and Mondavi Winery.
We employ advanced Computer Aided 3D Drafting (CAD) and Computer Aided Manufacturing (CAM) technologies to provide precision and efficiency in every project we undertake.
Business Services
- HVAC installation or replacement
- HVAC system repair
- Plumbing inspection
- Plumbing installation or replacement
- Water pipe installation
Business Location & Hours
Mon: | 7:30 AM - 4:30 PM |
Tue: | 7:30 AM - 4:30 PM |
Wed: | 7:30 AM - 4:30 PM |
Thu: | 7:30 AM - 4:30 PM |
Fri: | 7:30 AM - 4:30 PM |
Sat: | Closed |
Sun: | Closed |
Recommended Customer Reviews

Over the 12 years we've lived in our Sonoma home, we've had Peterson in for a few smaller jobs. To date, they were responsive and the work, although minor, was completed satisfactorily. We recently had a fail when turning on the furnace the first time this year and called them. A technician came out and diagnosed a faulty control board. He said they would call us with the price of the part. They called promptly and said it would be $170. The technician showed up a few days later at 8AM (no call from Peterson that he was coming out). He replaced the control board, tested it. He asked if we wanted a new digital thermostat, and since the one we had was from about late 90's, we said yes. He went out to the truck and installed a digital and showed us the basics on how to use it. (He did forget to leave the ""quick reference"" card for the thermostat, and we had to pick one up at Peterson.) We got the bill for the work a few days ago. Peterson's charged $114 for a thermostat that retails for $48.00 and $181 (it was quoted to us at $170) for a control board that retails for $119. We called about the excessive mark up of items we could have ordered ourselves and had the technician install, but they insisted that they charge standard mark-up. Really? Over 100% for the thermostat and over 65% for the control board?? Businesses should know that customers can check prices for just about anything on the internet. Of course they do not pay full retail, so we have no idea what they actually pay for these two items. Needless to say, we'll be looking for another vendor for a new furnace and AC when the time comes.

Scott did an amazing job at installing an HVAC system for my place in Sonoma. He provided a well considered estimate, which was detailed and well documented. The work was done on time and efficiently. Also the final product was great - super good to have it properly and professionally installed. The working crew was highly professional. Thanks to Scott for the work!

The compressor for my three-year-old A/C was rattling badly. Peterson Mechanical's servicemen showed up EARLY, diagnosed the problem quickly (a circuit was blown out), and fixed it right away. Whole service visit was less than 45 minutes. Courteous, efficient, speedy, excellent. Five stars.

I've been a Peterson Mechanical customer for years and they are fantastic. I highly recommend them on a regular basis and will continue to do so. I've used them for my home as well as my office and they've been great at both the residential and commercial side. They are always honest and timely.
They are a family owned and operated business with deep roots in Sonoma Valley which is important to me as a Sonoma local.

This company's incompetent repair work could have caused my niece's home to explode causing major property damage in the least and possibly bodily injury or death. She called them in to repair a wall heater which had previously worked fine and they managed to screw up the repair so badly that the furnace leaked gas because they didn't know what they were doing. They misdiagnosed the problem in the first place and went for the more expensive solution of replacing the main control valve then managed to either install it incorrectly or used the wrong one. It's lucky that when my niece entered the home the next she didn't create some kind of ignition source and blow the place up with her in it. She immediately called PG&E (who were helpful) who came out and shut off the gas. And then on top of all of this Peterson himself gave some song and dance BS excuse for why they screwed up and pointing the blame elsewhere to deflect it from where it really lay. The furnace was in fairly new condition and worked fine for 2 years previously and was checked by PG&E when it was installed. It should have been an easy fix for a competent repair technician but they managed to create a dangerous situation where none existed before. In spite of some of the good reviews here, I'm saying beware of this company. Performing poor work is one thing, but then not taking responsibility for their mistakes is really bad business.

I love this company, especially Jake. He loves to solve repair problems. If you are interested, he will take the time and explain to you what is going on with your furnace, air-conditioner, etc. He has a gift for repairing that which is broken and is personable as well. He is intelligent, proficient, responsible, trustworthy, and has a great personality. This is the second time that we have called Peterson Mechanical. The first was for our air-conditioner. That was about 7 years ago, and we have not had to call for a repair service since. Today, it was for our furnace, and I am so happy that they were there for us. It is wonderful to have the furnace working again.

Had a problem with my furnace and within an hour someone was servicing it.
Chris was great and I will tell everyone to call them.
Very responsible company.

July 1, 2013. The recent hot spell has caused us to turn on our air conditioner. Yes, the one Peterson Mechanical specified, installed and repaired. As it has since each summer since it was put in, it failed to work. We called a new HVAC company to service it. They came out and the connection to the compressor was leaking. This is exactly the repair that Peterson did less than a year ago..for a cost of $500+..

I've used Peterson twice now, this time for a heater repair. They were prompt, quickly determined the problem, and immediately made the fix. I will use them again.

Thoroughly professional in every way. I just had a new furnace installed in my new home, and added A/C. Peterson also installed a dryer vent to the exterior. They were the only company who returned my calls promptly. The installers were on time, polite, very clean, and wonderful to deal with. All system operations were explained clearly.
Peterson Mechanical is The Best.