Which Equipment Is Affected because of Colorado House Bill 23-1161?

HB 23-1161 primarily affects new gas-fired furnaces and water heaters installed after the effective date. Homeowners planning equipment upgrades in Colorado should be aware of how these rules apply.

• Gas water heaters up to specific BTU input levels must comply with strict ultra-low NOₓ emission limits.
• Gas furnaces, including common fan-type central furnaces, are also required to meet ultra-low NOₓ standards.
• Electric equipment, such as heat pumps, electric furnaces, and electric water heaters, is not subject to NOₓ emission limits.
• If you purchase new gas heating equipment after January 1, 2026, your choices will be limited to models that meet the updated ultra-low NOₓ emission requirements.

Understanding which systems are affected can help you plan ahead, avoid surprises, and choose equipment that meets Colorado’s upcoming environmental standards.