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hvac service graphicSchedule preventative maintenance of any make, model, or style of heating system, and trust the professionals from Welzig Heating and Air to optimize performance.  As a Bryant Factory Authorized Dealer, our NATE-certified technicians are extensively trained, regularly updated, and follow rigid service procedures.  We do more than fulfill the requirements of warranty coverage.  We take the opportunity to inspect all components, providing the expert troubleshooting, tuning, and cleaning that protects against malfunctions, elevated sound levels, hazardous situations, degraded air quality, diminished comfort, and excessive energy use.  Established in 1994, Welzig Heating and Air is family owned and committed to higher standards of excellence.  When our residential and commercial customers throughout Boulder, CO and surrounding areas turn to us for proactive upkeep, we answer with the skilled and courteous service that earns your satisfaction.

Stay up to date on your heating service!

Over ninety percent of system failures are caused by a simple buildup of dirt and dust.  An accumulation of only .042 inches on a heating coil can compromise efficiency by 21%, significantly impacting the cost of keeping a comfortable home.  A collection of contaminants on the fan can reduce the CFM (cubic feet of air per minute) by 50%, and is the most common cause of cracks in heat exchangers.

Regular heating service from Welzig Heating and Air will keep your system running longer and more efficiently!

With thorough cleaning from Welzig Heating and Air, wear and tear and premature failure of your system is defended against.  We ensure maximum airflow for restored heating capacity, energy efficiency, and safety, cutting operational costs while enhancing comfort.  Call on Welzig Heating and Air for a job done right.  We take the time, care, and necessary steps to deliver greater rewards from your investment, living up to our reputation for quality services across Boulder, Longmont, Louisville, and Lafayette, CO.

Satisfied Customers
They Speak For Us

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.


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!


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.

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