Keeping Your Home Cozy, Season After Season.

Top-Rated Heating & Air Conditioning in Boulder, CO and surrounding areas

Heating

Our Heating products are designed to provide efficient and reliable heating and cooling solutions for your home or business.

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Cooling

From ductless mini-splits to central AC units, our air conditioning products provide reliable cooling and improved indoor comfort

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Current Offers

Elevate comfort with HVAC promotions! Our heating solutions ensure efficient, reliable climate control for your home or business.

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About Us

Providing Comfort every hour, in every season

Whether you need fast, reliable service or you’re planning to upgrade your home with new heating or cooling equipment, KJ Thomas Mechanical is here to help. We’ve built a strong reputation in the community—ask around and you’ll hear the same thing: we go above and beyond to earn your trust, so we’re the first call you make today—and every time after.

Why Choose Us?

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Experienced Technicians: Our skilled technicians bring years of experience and knowledge to every job.
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Comprehensive Services: From routine maintenance to emergency repairs, we've got your HVAC needs covered.
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Timely and Reliable: Count on us for prompt service that fits your schedule, ensuring your comfort is never compromised.
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Customer-Focused Approach: Your satisfaction is our priority, and we go the extra mile to exceed your expectations.

FINANCING OPTIONS

FLEXIBLE LENDING OPTIONS FOR YOUR NEW SYSTEM

At KJ Thomas Mechanical, we believe everyone deserves a comfortable home. That’s why we’ve teamed up with Wells Fargo to provide flexible financing options for your HVAC needs. With convenient payment plans and trusted support, you can invest in reliable heating and cooling solutions that fit your budget. Discover how easy it is to bring home comfort within reach. Financing Subject to Approval.

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Next-Level Comfort Starts Here.

Our website is packed with helpful resources to help you better understand your HVAC systems and learn how to keep them running efficiently. Struggling with temperature inconsistencies, humidity issues, or allergy concerns? You don’t have to settle for discomfort—our experts can help you solve those problems and create a healthier, more comfortable indoor environment.

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Testimonials

SEE WHAT YOUR NEIGHBORS ARE SAYING ABOUT KJ Thomas Mechanical

Sally W.
Sally W.
21:10 07 Jul 25
I called KJ Thomas Mechanical when my AC suddenly... stopped working on a holiday weekend. They worked me in right away. Daisha was very thorough and explained everything she was going to check and why. She diagnosed the problem and had a replacement part ordered right away. I will definitely use them again.read more
Donald L.
Donald L.
17:54 01 Jul 25
I just contracted with Karl, haven't had the... install yet so this review is based on my first interaction with Karl. I went with Karl over 4 other estimates I got because Karl was extremely honest and helpful and his price was good.read more
Francis
Francis
10:53 22 Jun 25
On time arrival. Called prior to arrival as... requested. Daisha was friendly and answered all my questions. Dog friendly!! Cleaned up the area upon completion of the job!read more
Joan B.
Joan B.
20:24 20 Jun 25
Wonder service as usual from Daisha!The units... look factory new after cleaning. She is very thorough and knowledgeable and answers all of my silly questions.read more
Mary C.
Mary C.
19:33 20 Jun 25
Daisha was friendly, very efficient, found the... problem replaced the part in a timely matter, and now I have a working AC again. Yay!read more
RuthAnne S.
RuthAnne S.
15:48 12 Jun 25
KJ Thomas Mechanical just came out to fix my air... conditioning unit. I am so pleased. Daisha, the technician, was polite and professional. She discovered the issue right away and plans to come back out with the part on the weekend because she knows it is going to be HOT. I so appreciate the caring service of everyone at KJ Thomas Mechanical.read more
Dennis
Dennis
19:45 02 Jun 25
Great experience yet again - thanks!
Dean A.
Dean A.
18:53 19 May 25
Daisha arrived on time was professional checked... and serviced our AC.All good!!read more
Janet
Janet
12:33 13 May 25
The A/C tech for my rental property, Daisha, has... performed comprehensive maintenance for a few years now. She is always friendly and courteous and has kept the A/C unit in great working order!read more
Susan R.
Susan R.
22:13 12 May 25
Daisha’s the best and always does solid work!
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