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Considered as part of the Nebraska Territory until 1861, when the Territory of Colorado was created by the US Congress, Boulder City served as a supply base for miners heading into the mountains.  Today, Boulder is the county seat, and often called “the city nestled between the mountains and reality.” Tucked into the foothills of the Rocky Mountains, Boulder offers everything from upscale shopping, craft breweries, restaurants, and history to 155 miles of trails that residents continue to work to conserve.  More than 60 parks, canyons, cliffs, rushing water, and an abundance of gorgeous scenery are always within reach.

Call Welzig Heating and Air for reliable AC & Heating Repairs in Boulder, CO!

Family-owned, Welzig Heating and Air is dedicated to providing an honest, affordable, and reliable source for residential and commercial heating, cooling, air quality, and water heating services in Boulder.  We focus on quality. Handling new/design installation and retrofit of top quality equipment, we deliver customized solutions to meet your specific requirement and expectations.

Top quality heating & cooling service, repairs & installations in Boulder!

Our factory authorized, highly trained, NATE-certified technicians further offer essential maintenance and skilled repair of all makes and models, taking every opportunity to optimize long-term performance.  Contact Welzig Heating and Air at (720) 336-3777 at anytime. We remain on call 24/7 for Emergency Service throughout Boulder.

Here are some of the services that we provide throughout the Boulder, CO area:

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Bob came out to look at our swamp cooler and was remarkably helpful and professional. Not only did he give me a knowledgeable diagnosis, but he also taught me a lot in the process. We’ll be calling him for all future needs with our cooling system.


Our 23-year-old A/C system ran out of “borrowed time” and became too difficult to continue maintaining. With great advice from Casey Welzig,, we replaced the old system with a Bryant Evolution A/C system. Max Loustaunau and Seth Bernhardt did an excellent job with removing the old system and installing the new one. Both of them are great to work with — very professional and very personable. We are really amazed at how much better the new system works!


Dave Kaplan-Gomez and James Miltersen installed my new Tankless Water Heater. Both were polite and professional. Care was taken not to damage anything in my house which I really appreciated. I use Welzig for all my HVAC needs and highly recommend them.

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