HVAC reviews in Longmont, Colorado

KJ Thomas Mechanical installed both a replacement furnace and a replacement AC set up for me. They were very responsive throughout the entire process. When issues came up that needed addressing they walked through the available alternatives and applied no pressure in choosing what particular method should be chosen. They were also very quick to respond to and resolve a minor oversight that was discovered later in the week. I would recommend them for being honest, professional, and quite concerned about taking care of their customers.

I've already left them a glowing review, but want to leave a second one. Karl and his team (Ann) continue to be amazing. Karl spoke with me extensively this week about potential issues a duct cleaning company created on the new furnace Karl installed in March and gave me some valuable advice. Thank you so much!

This was my fourth time which I contacted KJ Mechanical, Three times for own house and once was for my daughter's house air conditioning. Three time Karl did the job himself or with other team members, The very recent A team member (Brad) worked on my heater and got that running smoothly. Can not say enough how nice and courteous and knowledgeable Brad was. They all knowledgeable and have my highest recommendation. If I was not quite satisfied at first time, I would not have recommended to my daughter and called for the forth times. Thank you Guys for the job well done.

The appointment (a furnace inspection, cleaning, and maintenance) was easy to schedule. The technician Daisha was prompt, efficient, and knew what she was doing. Very pleasant experience!

I work for a home inspector training company and we wanted to include a working mini-split in our classroom as a demonstration. We are beyond pleased with KJ Thomas Mechanical. They were incredibly prompt, communicative and were able to work with us on the best unit for our budget (since we are not actually trying to use it for a residential dwelling). They even created a custom platform so we can move the mini-split around our classroom/take for traveling purposes. Highly recommend!

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.

KJ Mechanical installed our Mitsubishi air source heat pump in December, 2023. We could not be happier. We needed to replace an aging propane furnace. They won our business because of product and price, and because they were sensitive to our needs for a system that would meet rebate and tax credit criteria and that would work well with the energy efficient design of our home. They were creative and proposed a somewhat more complicated system that was less expensive and solved an HVAC problem we had previously ignored. They started installation less than a week after we paid our deposit. Installation was efficient, with two teams working in parallel on various system components. Tate, Daisha, and Juan were courteous; they spread drop cloths mornings and cleaned up evenings. When a controller setting was wrong, Karl arrived early the next day to help fix the problem. The staff solved one problem after another as we navigated through tax credit and rebate applications and as agencies changed rules and lists of qualifying equipment.

As for the heat pump system itself, it is a dream! It includes a Mitsubishi “Smart Multi” M-Series H2i outdoor condenser unit with matching indoor air handling unit to integrate with our existing ductwork plus a cassette air handler that is recessed into the ceiling. Heating is excellent, performing well even during January’s minus-15-degree cold spell, especially after replacing the “free” but ineffective remote controller shipped with the ceiling cassette with a better unit whose features are like the main thermostat. The system is so efficient that it is already saving us money; we had originally estimated that this wouldn’t happen until propane prices substantially increased, . We are thrilled in the final outcome and thankful to Karl and his team at KJ Mechanical.

Excellent install and service. KJT Mechanical helped us with finding and install of new more efficient heat pump/ furnace system. New system needed some tweaks to deal with the wacky -11 to 50 temp swings we experienced. Ann got us scheduled between our work at home and pick up kids times. And the gentlemen who came out to install and tweak were efficient, knowledgeable and kind. Thank you.

Karl arrived promptly, and within 10 minutes, had diagnosed and fixed the problem with our air conditioner. We had also called him out to get a bid on a replacement air conditioner and heater system. He had a strong grasp of what was needed, as well as all the various options (heat pump with backup heater versus heater and AC, etc).

Karl came over to discuss how to improve our current HVAC system. He was professional and knowledgable. I really appreciated his time, honesty, and willingness to think about different ways to help us in the most cost effective manner. I would highly recommend Karl for his insight and integrity.

Going through the quoting/estimate stage currently. So far so good. Karl was very knowledgeable about HVAC and his product lines. Karl was also willing to brainstorm and listen to my ideas (others just want to pick a standard solution and do it.) Updates later after we get further along in the process.

Our furnace broke and the team at KJ Thomas Mechanical gave us reasonably priced options and did a great job installing it. They even fixed our dryer vent that wasn’t attached properly! Excellent work at an excellent price!

Cooper was knowledgeable, personable, and identified the issue with our heating. Thank you!

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!

Curtious interactions and thorough evaluation and installation of a heat pump, humidifier and new furnace. Very professional!

Daisha was wonderful tuning up our furnace for the winter. She is obviously very experienced and knowledgeable. She answered all my questions. I enjoyed meeting her and I so appreciate her helping us face the cold weather!

Tate showed up on time, did a thorough job, and answered all my questions. I will use them again.

Colin was very thorough. He was polite, efficient and answered all my questions.
He provided info on new humidifier filters and helped me order directly from the company. This saved time and money. I always recommend KJ Mechanical for all my HVAC needs!

Tate did a great job diagnosing and fixing my thermostat problem.

They have skilled technicians who can resolve your issue effectively, but be cautious—they may try to seriously overcharge you for parts. While I’m fine with paying a reasonable markup for the convenience of having the part available, a 400-500% increase is downright outrageous. I've attached the initial and revised estimates as evidence. What really pissed me off, though, is that they tacked on an extra 15 minutes of labor to cover the time spent negotiating a fair price for the part. Absolutely unacceptable.

Great service after the purchase, very very very timely. Very rare in the service industry -- much appreciated.