Furnace Installation & Replacement in Arvada

Gas furnaces lose about 4% of their rated output for every 1,000 feet above sea level, which is about 22% at Arvada's elevation. A furnace sold as 80,000 Btu/h input delivers closer to 62,000 Btu/h of input here once it is correctly derated with high-altitude orifices and the right manifold pressure. Skip that step and the burner overfires, which shortens heat exchanger life.

We run a Manual J load calculation on every replacement instead of copying the old furnace's size. A 1970s house that has since gained attic insulation and newer windows often needs less furnace than it has. The city's Building Safety Division treats a capacity change of 5% or more as a modification, so having the Manual J on paper also keeps the permit moving.

Since January 1, 2026, a new gas furnace sold in Colorado must emit no more than 14 ng/J of NOx or be certified to the current ENERGY STAR version, which since July 31, 2026 means about 97% AFUE in northern states. Gas furnaces are still installed every day; the law just narrows the model list. Every quote we give for an Arvada home names the compliance path for the model being offered. Our guide to Colorado's furnace NOx rules explains the details.

In Olde Town and the older postwar blocks, the furnace and water heater often share a masonry chimney or a metal B-vent. An ultra-low NOx 80% furnace can keep using that vent if it is sized and lined correctly. A condensing furnace vents through PVC out a sidewall or the roof and needs a condensate drain, and that change can leave the water heater alone in a chimney sized for two appliances. The fuel gas code then requires the remaining vent to be resized, often with a liner, and that cost belongs in the quote.

In Candelas and Leyden Rock, the existing furnace is usually condensing already, so the PVC intake and exhaust can often be reused after we check the pipe size and termination clearances.

We pull the residential mechanical permit through the City of Arvada using our Arvada mechanical license and book the final inspection. Both your gas and your electric service come from Xcel Energy. Its older rebate summaries listed a rebate for a 95% furnace replacing a non-condensing unit, but an outside rebate database lists Xcel's furnace rebates as discontinued from January 1, 2026, so we confirm what is current before you count on anything.

If your central AC is also near the end, a cold-climate heat pump or a dual-fuel setup is worth pricing alongside the furnace. Colorado's 2026 heat pump credit is $1,000 for air-source systems, and Power Ahead Colorado offers $1,500 for cold-climate units when the contractor applies before work starts. The federal 25C credit ended after 2025.