Plumbing Heating and Air Conditioning in Montgomery

Mechanical Contractors

The #1 Choice for Residential, Industrial, Commercial & Municipal Projects Since 1926!

Est. 1926

What R.J. O'neil
has to offer

The Mechanical Equipment in your buildings is often the most expensive and the greatest energy consuming part of your operations, yet it is mostly out of sight and out of mind until something goes wrong and the sewers are backing up in your office, or water is spraying all over your computer equipment, or your heat goes off on Christmas Eve, or your air conditioning goes down two hours before a very important client meeting. These things happen.


At times like these how important is it to have someone you know, someone who you have an established relationship with, someone you trust, who knows your building, who knows your equipment, who knows your personnel, who is only a phone call away. Someone who will come 24 hrs a day ,7 days a week 365 days a year, someone who has the resources to get a supply house opened up on New Years day, Someone who can bring their own crane, or backhoe, or certified welders to your site at midnight if need be, someone who will do whatever it takes to get you back in operation when things break down.

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Our Partners & Affiliations

What Our Customers Think

Julie Jones
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We have been using RJ O'Neil for years. Not only for home but also for business. First off I would like to comment on their vast knowledge, reliability and complete professionalism but equally as important are the people who work for this company. They are trustworthy, respectful, personable and just flat out good people. The response time is great and are very conscientious about cleaning up when they are done. We are a fan if you can't tell....... we highly recommend them
Sandi S.
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I was having drainage issues in several parts of my house. The tech repair man walked through my house and patiently listened to everything. He ended up recommending that I have my bathroom rodded out however he could have sold me additional services but told me they were not necessary. He was here and done in less than 60 minutes.
Cynthia Kaplanis
Ductless heating & A/C services
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Our air conditioner went out on a very hot morning. We call R.J. O'neil and they were at our house within 1 hour . The service was amazing. We will always use them when in need.
Kathy Garazin
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Arden from R.J. O'Neil came out to our commercial building on Christmas Eve on a quasi-emergency basis to turn off our water and blow out the pipes. And then Alex came out the Sunday after Christmas to get our HVAC units up and running again. Jessica in the office helped coordinate Alex being on standby on Sunday. We truly appreciate all of their assistance and the work they did for us. I would not hesitate to recommend them - they're awesome!
Justin Soofi
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Excellent communication (both via phone and email) and customer service from the first contact through completion. I was having a lot of trouble finding a company that could handle the install of my tankless water heater in a timely manner and they fit me in promptly. Quoted a rough estimate over the phone after hearing all the details and were very competitively priced. Actual job charges were in line with that estimate, which to me is commendable. Very professional on site and the work was done quickly and with care. Would definitely recommend.
Ravi Vaghani
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My furnace stopped working on a very cold day. I called R.J.O'Neil and they sent a technician right away. The Technician was very knowledgeable and went above and beyond to resolve the issue. One part needed a replacement and Jessica worked with the manufacturer to get the part covered under warranty to save us the cost. They kept me informed through out the process and provided time line to get the part in and get it replaced. Will definitely call them with any HVAC related issues. Keep up the Great Service.

We Service and Install All Major Brands


R.J. O’Neil Plumbing Services has been in business since 1926, providing quality plumbing and piping services to homeowners and businesses in the area. We’re licensed, bonded, and insured, and our team of experienced professionals is dedicated to providing the best possible service. We’re here to help you with everything from fixing a leaky faucet to installing a new water heater, and we’re always available to answer any questions you may have. We know how important it is to have reliable plumbing, and we’re committed to providing our customers with the highest quality service possible. Contact us today to schedule a free consultation, and let us show you why R.J. O’Neil Plumbing Services is the best choice for all your plumbing needs.

Plumbing Services


R.J. O’Neil is a company that provides HVAC services to the Chicagoland area. HVAC-R stands for heating, ventilation, air conditioning, and refrigeration. These services are important because they help to keep your home or office comfortable year-round. The ventilation system helps to circulate air throughout your home or office, and it also helps to remove pollutants and improve indoor air quality. R.J. O’Neil has a team of skilled technicians who can help you with all of your HVAC needs. Whether you need a new installation or a routine maintenance check, we can help you get the job done right!

HVAC-R SErvices

Maintenance Plans

R.J. O’Neil is dedicated to serving the Chicagoland area. Our quality work ethic and long-running history of professional skill is shown throughout our four generations of family owned business. 

Mechanical Construction

R.J. O’Neil strives to continue to build a culture rooted in team-oriented collaboration and can-do attitudes. It is these core values that lay the groundwork for a level of professionalism and excellence that consistently exceeds our customer’s high expectations.