Here’s what our customers are saying about us…

I hope you are doing well. I would like to take a moment to thank you for the work you
did on my home. You worked with me to find an AC/Furnace unit that was in my price
range and quality to replace an aging unit. You and your partner delivered the product as
promised and in a timely manner – and cleaned up!

In addition – you and your partner installed a tankless water heater to replace another
aging item in my home. You and your partner took care in protecting my newly installed
hardwood floors and once again installed the product in a timely manner and cleaned up
when finished!

I have known you for many years as you have taken care of my previous home – and
would recommend / refer you to anyone – anytime. Thanks for you professionalism and


In the fall of 2008, I was having some problems with my furnace. I called a local Longmont company,

that I was doing business with for the past year. They came over and looked over my furnace and air
conditioner and informed me that I needed to replace both items; they wanted to charge me over
$15,000.00. In my panic, my neighbor suggested that I call Karl, I did. Karl has been my furnace and air
conditioner tech since; he was honest about the air conditioner, that I would need a new one; Karl also
serviced the furnace, which I did not need a new one. The “company” was trying to rip me off.

Karl has been honest and fair with his prices and recommendations on the servicing of both units; I have
trusted and depended on Karl since 2008, I was not always available to be home, Karl has my house key
since we have been doing business, not once did Karl give me any reason not to trust him.

People at work has asked me what company I used for my furnace and air conditioner; I don’t use a
company I have Karl, someone that I have trusted for many years, I don’t let anyone else service the
units. A friend at work, asked the other day who I recommend, I gave out Karl’s phone number.



I have used the services of Karl Thomas for three years. He installed an exhaust system for my art studio when I bought my new home, and has checked my furnace each year since then. I also had him install a humidifier on my furnace, so he cleans that and services it as well. I have always found Karl to be trustworthy and fair in his pricing. As a single woman I appreciate having someone come into my home that I know is safe and honest.


Karl Thomas has been our “go-to” HVAC guy for over ten years now,
through several residential properties and a commercial property we
own. Karl really knows his stuff, and always tries to find economical
solutions to repairs and maintenance. He’s friendly, honest,
dependable, and communicative, so we wouldn’t trust our HVAC systems
to anyone else.
-Brian and Darlene
Estes Park


Karl has taken care of my family’s HAVC needs for more than 15 years and I would not even consider using any other company. During that time he has handled both routine maintenance and major projects including installation of 1) a new furnace and of 2) a high-tech, on-demand water heater. For all of these task his work has been consistently first rate. Karl is one of those rare individuals with both excellent technical abilities and very effective communication skills. He is creative in solving problems in the most cost effective way and equally effective in helping customers understand the costs, schedule, and trade offs association with the solution he is proposing. While dealing with an HAVC breakdown is almost always stressful, working with someone you can trust, like Karl, takes a lot of the hassle and anxiety out of the experience.



Karl has been my “go-to” person for the past 15 years. I have never had problems with the work he has done for me and know it will get done properly each time. He has installed and serviced two furnaces for me in different homes, and has installed and serviced an air conditioner, humidifier and a hot water heater in my present home. He is always professional and thorough, arrives on times and is very good natured as he helps me understand what needs to be done. His pricing has always been fair. Karl also has been very helpful when I need recommendations finding other experts for projects outside his scope of services. I highly recommend him. My dogs think he’s great also!



KJ Thomas Mechanical has both installed and serviced my heating, air conditioning and hot water heater for the last 10 years at two different homes. I would recommend him highly. He is always available when needed and provides great customer service!



Boulder County Heating & Air Conditioning since 1996