Furnace Installation & Replacement in Littleton

Rangeview dates from 1953, Broadmoor and Woodlawn were annexed in 1956, and Ridgewood followed in 1960. Houses in these neighborhoods are mostly ranches with basement furnaces that have been replaced several times, usually with the vent and trunk ducts left as they were. Arapaho Hills, a mid-century modern neighborhood on the National Register, has flat or low-slope roofs and compact mechanical spaces that limit where a new vent can go.

About half of Littleton's housing was built from 1970 to 1999, and furnaces from 2000s replacements in those homes are the next large group coming due.

Littleton's elevation means about a 22% derate. A furnace rated 80,000 Btu/h input at sea level runs at roughly 63,000 here after high-altitude orifices and gas pressure adjustments. Many postwar ranches have had attic insulation and window upgrades since their last furnace, so the Manual J often supports a smaller unit. In finished basements, we also check that the new furnace's airflow reaches the rooms upstairs, since those small ranches often rely on a single return. If the basement was finished after the last furnace went in, its rooms may have been tapped off existing supply ducts without any thought to balance, and a replacement is the best time to correct it.

New gas furnaces sold in Colorado since January 1, 2026 must emit no more than 14 ng/J of NOx or carry the current ENERGY STAR certification, which requires 97% AFUE in the North since July 31, 2026. In a postwar Littleton home with a chimney, that means a choice. An ultra-low NOx 80% furnace can reuse a chimney that is inspected and lined correctly. A 97% condensing furnace vents through PVC and drains condensate, and a water heater left on the chimney then needs a vent sized for it alone. In Arapaho Hills, the PVC route needs planning so it doesn't spoil the facade. Our NOx guide has more.

Inside the city, Xcel Energy supplies gas and electricity. A rebate tracker reports Xcel removed gas furnace rebates on January 1, 2026, and the city's own sustainability programs change, so we confirm what's open before quoting. Heat pumps still have broad support: Colorado's $1,000 air-source credit, Power Ahead Colorado's $1,500 cold-climate rebate and Xcel heat pump rebates, whose amounts changed October 1, 2026. For a small ranch without room for big ducts, see our mini-split guide.