Furnace Installation & Replacement in Northglenn

Most older Northglenn homes vent the furnace and water heater together into a masonry chimney or metal flue. Under the NOx limits that began January 1, 2026, the only new gas furnaces that can be sold in Colorado are ultra-low NOx models (14 ng/J or less) and those certified to the newest ENERGY STAR spec, which moved to 97% AFUE on July 31, 2026. That leaves two practical choices.

An ultra-low NOx 80% furnace can continue to use the existing vent if it is sized correctly and in good condition, which avoids new wall penetrations. A 97% condensing furnace vents through PVC, usually out a sidewall, and needs a condensate drain. With the furnace gone from the chimney, a gas water heater is left alone in a flue sized for two appliances. The code requires its vent to be resized, typically with a liner, and that cost should be on the quote. Our NOx guide walks through both paths.

At about 5,364 feet, a furnace loses roughly 21% of its sea-level rating. A 60,000 Btu/h input furnace delivers about 47,000 here after high-altitude orifices and gas pressure are set. We size from a Manual J using the local design temperature. Northglenn's record low of -24°F on December 22, 1990 is a reminder that a correct altitude setup matters, since an underfired or overfired furnace is least forgiving on the coldest nights.

Permits run through the Building Division at City Hall, where SAFEbuilt handles plan review and inspections under contract. Anyone you pay to replace a furnace needs a Northglenn contractor license and must pull the permit, and we hold the license and file the paperwork. Xcel Energy supplies gas and electricity. A rebate tracker reports Xcel ended gas furnace rebates on January 1, 2026, so we check what's current before quoting.

Many of these ranches have an aging central AC or a swamp cooler. If the AC is due too, a cold-climate heat pump or dual-fuel system can handle both jobs. A cold-climate unit can draw $1,500 from Power Ahead Colorado on top of the state's $1,000 air-source credit when the contractor applies before work starts, and Xcel heat pump rebates changed on October 1, 2026, so confirm current amounts. The federal 25C tax credit is gone for equipment installed after December 31, 2025.