Furnace Installation & Replacement in Frederick

Old Town Frederick dates to the coal-mining era, and its smaller houses may have furnaces in crawlspaces or closets, sometimes on old chimneys. Acreage homes around Nelson Lakes are larger and more exposed to wind. Both need a Manual J rather than a rule of thumb, and older homes often need vent work along with the new furnace.

Frederick's building code uses a winter design temperature of 1 degree Fahrenheit, and that's the number we put into a Manual J. At 4,938 feet, a gas furnace delivers about 80% of its sea-level input after high-altitude conversion with the correct orifices and gas pressure. Two-story 2000s homes are often best served by a two-stage or modulating furnace that runs longer at low fire, which evens out temperatures between floors better than a bigger single-stage unit.

The town has adopted the 2024 IRC, IMC, IFGC and IECC with local amendments, plus Colorado's Model Electric Ready and Solar Ready Code. On top of that, gas furnaces sold in Colorado since January 1, 2026 must meet 14 ng/J NOx or the current ENERGY STAR version. If your home already has a 90%-plus furnace on PVC, a condensing replacement is usually a direct swap, though we confirm the pipe size and length suit the new unit. If it has an 80% furnace on a metal vent, an ultra-low NOx 80% model can keep that vent, or you can move to condensing and reroute. Our NOx guide explains the rule.

According to the town's new-resident materials, gas service is from Black Hills Energy and power is from United Power. Because Xcel isn't the electric utility here, Xcel's heat pump rebates don't apply. Colorado's $1,000 air-source credit and Power Ahead Colorado's $1,500 cold-climate rebate do, and the federal 25C credit ended after 2025. Check with Black Hills and United Power for any current program of their own.

Our heat pump cost guide covers what to expect if you're considering one. The Town of Frederick Building Department issues the permit; we file it and schedule the inspection.