By Wk Real Estate - February 19, 2026
Starting January 1, 2026, all new gas furnaces and gas water heaters sold or installed in Colorado must meet ultra-low NOx (ULN) emissions standards. Equipment that was already in stock at local retailers on January 1 can continue to be sold and installed after the deadline, but as inventory runs out, new models will be replaced by units that meet the updated requirements.
Colorado’s new ru