Furnace Installation & Replacement in Firestone

Builders often install one furnace in the basement to heat three levels. The upstairs bedrooms get the least air and the most sun, so they're the usual complaint. A Manual J for each floor often shows the original furnace was sized correctly for the whole house but delivers too little to the top floor. A two-stage or variable-speed furnace, a bigger return upstairs and balanced dampers usually fix it. At 4,856 feet, a gas furnace delivers about 81% of its sea-level input after high-altitude conversion, and we set orifices and pressure accordingly.

Since January 1, 2026, Colorado has required new gas furnaces to meet 14 ng/J NOx or the newest ENERGY STAR version. If your home already has a condensing furnace on PVC, a 97% replacement usually uses the same vent path after we confirm pipe size and length. If it has an 80% furnace on a metal vent shared with the water heater, an ultra-low NOx 80% furnace can stay on that vent. Our NOx guide explains the details.

The Town of Firestone Building Division at 9950 Park Ave issues the permit. The town's fees list one permit that covers a furnace replacement, an AC replacement or the two together; a water heater is permitted separately, and a brand-new AC carries an added electrical fee. If you're replacing the furnace and AC together, that combined permit keeps the paperwork simple. We pull it and schedule the inspection.

For Barefoot Lakes, the builder lists Black Hills Energy for gas and United Power for electricity; other parts of town may differ, so check your bill. With United Power as your electric utility, Xcel's heat pump rebates don't apply, but Colorado's $1,000 air-source credit and Power Ahead Colorado's $1,500 cold-climate rebate do. The federal 25C credit ended after 2025.

If your AC is as old as your furnace, a heat pump or dual-fuel system can replace both. Our heat pump vs. furnace guide compares the options.