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Heating & Cooling Across Colorado(303) 879-1746  |  contact@frostpeakcolorado.com
Frost Peak Heating & Cooling
Colorado HVAC

Longmont Heating & Cooling

HVAC Services in Longmont, CO

Longmont sits at 4,981 feet where the plains meet the foothills, with Longs Peak on the horizon and the St. Vrain River running through town. From Old Town to the subdivisions west of Hover Street, our HVAC technicians repair, install, and maintain the furnaces, boilers, heat pumps, and air conditioners Longmont homes depend on.

Historic brick storefronts on a Longmont main street with Longs Peak behind the city

Longmont Services for Old Town and New Builds

Longmont pairs an Old Town core with subdivisions west of Hover Street at 4,981 feet, where foothill wind, hard water, and greenway moisture drive the work in the twelve services below.

Furnace Repair & Installation

Foothill wind drives cold into Longmont homes, and we repair ignition trouble, cold air, and short cycling in Old Town and Bohn Farm furnaces, and replace units that keep failing.

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Indoor Air Quality

Greenway moisture leaves some Longmont homes musty while winter air dries the rest, so dehumidifiers, filters, and ventilation even things out.

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ERV Installation

A Longmont home sealed against foothill wind traps stale air, and an ERV swaps it for fresh air while holding onto heat.

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Longmont Foothill Wind, Hard Water, and Greenway Moisture

Foothill wind finds leaks. When foothill wind finds leaky ducts and wall gaps, the windward rooms are the first to run cold. We seal ductwork and check airflow so heat stays inside.

Hard water and boilers. Old Town Longmont radiators run on boilers where scale gathers on water-fed parts, and the warning signs are noise, slow heating, or a leak. We flush and service boilers and flag scale damage early, so Old Town Longmont radiators keep heating evenly.

Old Town ductwork. Late-1800s to early-1900s Old Town homes often have ducts sized for a different era, so some rooms run hot while others stay cold. We test airflow, seal leaks, and rebalance supply.

Greenway moisture. Homes near the St. Vrain River greenway see more moisture than homes on higher ground, and that shows up as musty air and condensation. We check ventilation and drainage along with the heating and cooling system.

Hot summers, hard-working AC. When a long, hot afternoon leans on a Longmont AC unit, low refrigerant or a dirty coil answers back as warm air or a frozen line. We find the cause and restore cooling from Old Town to the subdivisions west of Hover Street.

With foothill wind over Old Town and storms dropping snow fast toward the subdivisions west of Hover Street, the National Weather Service forecast office in Boulder carries the Longmont forecast, and the EPA indoor air quality pages cover indoor air for homes near the St. Vrain River greenway and the west side.

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Longmont Heating and Cooling West of Hover Street

Longmont sits where the plains meet the foothills, and its weather shows both. Foothill storms drop snow fast, plains wind drives cold air into homes, and summer afternoons climb high. The St. Vrain River greenway adds moisture and shade through town. Where the plains meet the foothills, a Longmont system faces wind, snow, and heat all in the same year.

Housing in Longmont runs from late-1800s to early-1900s Old Town homes to 1950s to 1970s builds and new subdivisions. Old Town homes often carry old ductwork, radiators, and boilers. Newer homes run on high-efficiency furnaces, heat pumps, and AC units. Longmont homeowners spot the hard water first on their fixtures, where mineral scale builds, and that same water works on boilers and water-fed heating parts.

Heating Trouble in Longmont?

Tell us what your system is doing, from an Old Town furnace with original ductwork to a Union Pointe heat pump struggling in foothill wind, and we will walk through the next steps with you.

Two-story home in Longmont with a wide lawn, large cottonwood trees, and mountains behind it

Longmont Neighborhoods, Old Town to Hover Street

We cover Longmont from Old Town to the subdivisions west of Hover Street, including:

  • Old Town
  • Bohn Farm
  • Aspen Grove Village
  • Union Pointe
  • Subdivisions west of Hover Street

Across Longmont, from Old Town to Bohn Farm, the ZIPs we cover are 80501, 80502, 80503, and 80504.

Longmont Landmarks: Roosevelt Park and the St. Vrain Greenway

Roosevelt Park and the St. Vrain River Greenway run through town, Downtown Main Street anchors the historic core, and Union Reservoir sits on the northeast side. Longmont United Hospital serves the area, and Vance Brand Municipal Airport (LMO) sits south of town.

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Longmont Homeowner Q and A

Yes. We serve Old Town, Bohn Farm, Aspen Grove Village, Union Pointe, and the subdivisions west of Hover Street, along with the rest of Longmont. Tell us your neighborhood when you call so we can plan the visit.

When foothill wind finds leaky ducts and wall gaps, the windward rooms are the first to run cold. We seal ductwork, test airflow, and check insulation gaps so heat stays inside and reaches every room from Old Town to the west side.

Mineral scale is a common cause. Longmont water leaves scale behind. Homeowners already notice it on fixtures, and inside boilers and water-fed heating parts that buildup causes knocking, slow heating, and leaks. We flush and service boilers and flag scale damage before it spreads, so Old Town radiators keep heating evenly.

Yes. Modern cold-climate heat pumps heat through Longmont winters and cool in summer, and west of Hover Street they have to handle foothill wind and cold snaps. We size them for the house itself, whether that is an Old Town home with original ductwork or a newer subdivision home west of Hover Street, and check defrost cycles, airflow, and refrigerant charge so they hold output on cold nights.

Homes near the St. Vrain River greenway see more moisture than homes on higher ground. Poor ventilation and a clogged condensate drain add to it. We check ventilation, drainage, and ductwork to find the cause.

Ahead of the first foothill storm, swap the filter, clear vents and returns, and have the furnace or boiler checked. We inspect burners, ignition, safety controls, and airflow, and we flag worn parts before a cold night under Longs Peak tests them.

Last updated: October 16, 2026.

Help for Your Longmont Furnace or AC

Foothill wind and hard water wear Longmont systems down, so call us or send a message when yours starts missing and tell us what it is doing.

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