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What HVAC Services Does McCormick Provide in Longmont?
McCormick provides residential heating and cooling service throughout Longmont, from Southmoor Park and Bohn Farms to Pleasant Valley, Kensington, and Pinnacle at Ute Creek.
Our NATE- and EPA-certified technicians handle furnace repair, furnace installation and replacement, furnace tune-up and maintenance, and emergency furnace repair — the full range of heating services — along with AC repair and replacement for Longmont summers that have historically reached as high as 106°F.
If your furnace has already failed and you want to know exactly how we diagnose and fix it, see our dedicated page for furnace repair in Longmont.
Why Do Longmont Homes Have Specific Heating Needs?
Three numbers explain Longmont's heating profile.
First, elevation: at 4,981 feet, combustion equipment must be properly derated and tuned for thinner air, or it will short-cycle and underperform.
Second, the heating load: Longmont accumulates 6,578 heating degree days per year (NOAA 1991–2020), well above Greeley's 5,431 at the other end of our service areas.
Third, the age of the housing: the median Longmont home was built in 1991, but 37.1% of the stock predates 1980. The 1970s alone account for 19.3% of all housing, the single largest decade. Those 1970s homes were built around furnace and venting designs that have since been replaced twice over, which is why a Longmont replacement is rarely a like-for-like swap.
Longmont's winters also punish deferred maintenance. The city's record low is −38°F, set on January 16, 1930, and modern cold snaps still push overnight temperatures into the negative twenties. In a pre-1980 home, that is exactly when a furnace at the end of its cycle gives out.
We serve neighboring cities too (see our pages for Loveland and Firestone) but the housing-age math above is Longmont's alone.
Who Permits a Furnace Replacement in Longmont?
For most Longmont addresses, the City of Longmont Building Inspection division is the permit authority. Since July 1, 2026, the city has enforced the 2024 IRC, IMC, IFGC, and IECC with the 2024 Metro Cohort Model Code amendments. This is a different amendment set than what Larimer County cities use, which matters when a contractor works both sides of the county line.
Longmont also has a wrinkle most Front Range cities don't: it is a Boulder County city with a Weld County portion. A furnace replacement in Southmoor Park or Bohn Farms may not have the same permitting requirements as one at a Weld-side address. Part of what you're hiring us for is knowing which conversation you're in before the work starts.
Fast after-hours emergency HVAC service when your system can't wait.
How Fast Can McCormick Reach Longmont?
Call (720) 443-2690. Your call is answered by our Greeley office at 2881 S 31st Ave, and a technician is sent from there to your Longmont address. Tell us your neighborhood and what the system is doing. An older home near downtown Longmont and newer construction on the edges of town tend to have different equipment, and the more we know before the truck leaves, the better prepared your technician is.
Frequently Asked Questions (FAQ)
Longmont's Trusted Heating & Cooling Team
Homeowners across Longmont and Northern Colorado have left McCormick Heating & Cooling more than 800 Google reviews, and every technician we send into a Longmont home is NATE- and EPA-certified, and the company is insured in Colorado.
When your furnace quits on a subzero Longmont night or your AC gives up in July, Call (720) 443-2690.
McCormick Heating & Cooling · 2881 S 31st Ave #3, Greeley, CO 80631, United States
Looking for cooling instead? See our air conditioning services, or browse all our HVAC services.
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