Denver homeowner guide
Colorado HB23-1161 & Gas Furnaces — What You Should Know
If you are replacing a furnace in Colorado, you may hear contractors reference HB23-1161. This page explains—in plain language—what that usually means for new installs, what it does not change about repairs, and what to ask before you sign a quote.
Disclaimer: Denver's Best Heating and AC Repair provides this overview for educational purposes as HVAC contractors. It is not legal advice. Rule details can evolve — verify current regulatory language with the State of Colorado and your installer’s AHRI–listed equipment documentation.
The short version
- HB23-1161 targets NOx emissions from new residential gas furnaces sold in Colorado and pushes the supply chain toward ultra-low NOx compliant equipment.
- For many homes, the practical result is that new furnace replacements are quoted as high-efficiency (often 96%+ AFUE) systems that meet the compliance pathways installers use every day — not legacy minimum-efficiency designs.
- Existing furnaces are generally grandfathered in the sense that you are not forced to swap out a working unit solely because of this law.
- Repairs on equipment already in your home remain a normal service — the policy focus is on what gets sold as new.
Why Colorado passed furnace NOx rules
NOx contributes to Front Range ozone issues during warmer months. Residential combustion equipment is one slice of the overall picture. HB23-1161 is part of Colorado's broader effort to tighten emissions from new furnace sales so replacements pollute less than older designs over time.
What Denver homeowners should verify on a quote
- Model numbers (indoor furnace + matching controls if communicating).
- AFUE and whether the proposed system meets the compliance pathway your contractor is using.
- Manual J heat load documentation — sizing matters at altitude.
- Venting / condensate / combustion air plan for high-efficiency furnaces.
- Permit & inspection scope (Denver metro jurisdictions vary).
- Warranty registration responsibilities and what is parts vs labor.
Ready to compare options? Start with our furnace installation overview or installation cost guide.
Official sources
For the statutory text and amendments, use the Colorado General Assembly bill record for HB23-1161 and follow guidance from Colorado environmental regulators for consumer-facing summaries.
View HB23-1161 on leg.colorado.gov →Related reading
HB23-1161 FAQs
Questions About a Furnace Replacement?
Call 303-327-9208 24/7 or request an estimate — we'll explain compliant equipment options for your home.
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