Colorado’s New Law
Colorado’s new HVAC law is no longer on the horizon; it’s here. As of January 1, 2026, House Bill 23-1161 is in effect, changing the types of furnaces and water heaters that can be sold and installed across Colorado. But don’t worry. The law doesn’t require you to replace a working system, and it doesn’t eliminate gas appliances altogether. What it does do is set new, much stricter emission standards for the equipment available when it’s time for a replacement. Available systems now need to meet updated low-NOx standards.
Below, the team at Absolute Plumbing, Electrical, Heating & Air breaks down what’s changed, what hasn’t, and how to make a smart plan under the new rules for when the first Denver cold snap arrives.
Colorado HVAC Law 2026: The Quick Summary
If you only have a minute, here are the facts every Colorado homeowner should know about HB23-1161:
- The law is now in effect statewide as of January 1, 2026
- It applies to most new gas furnaces and gas water heaters sold or installed in Colorado
- Covered equipment must meet ultra-low NOx (nitrogen oxide) emission limits
- Existing systems aren’t affected. You can keep and repair what you have
- Only compliant equipment is now available for new installations in most cases.
- Planning early gives you more equipment choices, better pricing, and access to rebates
What Is HB23-1161?
HB23-1161 is a Colorado state law signed in 2023 to reduce air pollution from common home appliances. As part of the Colorado HVAC law 2026, the state began enforcing new, lower NOx emission standards for gas-fired central furnaces (the fan-type units that push heated air through ductwork) and gas water heaters starting January 1, 2026. The important takeaway is that HB23-1161 is an emissions standard, not a ban. It’s based around NOx levels.
What is NOx?
NOx stands for nitrogen oxides. These are gases produced whenever natural gas is burned. When they’re burned at higher temperatures, NOx pollution contributes to smog, ground-level ozone, and even respiratory problems like asthma.
An ultra-low NOx furnace or water heater uses a different burner to cut those emissions while still delivering the heating and hot water performance Colorado homes need.
What the Colorado Furnace Law Means for Homeowners
The easiest way to understand the Colorado HVAC law is to know what’s changing and what isn’t.
What Has Changed
The biggest shift under the Colorado HVAC law 2026 is in the replacement market. This means that when your current system reaches the end of its life, your replacement options will be different than they were in previous years.
While pricing and availability can vary, the key takeaway is simple: you still have options, but those options are now shaped by updated emissions standards rather than older equipment models. For more info, read our guide on what to do if you’re replacing a furnace after the cutoff.
What Hasn’t Changed
If your current gas furnace or gas water heater is working properly, you don’t need to replace it. Repairs and maintenance are still okay, too. Absolute HVAC technicians can keep servicing, maintaining, and repairing your furnace or water heater for as long as it remains safe and operational.
Also, keep in mind that this law really targets residential heating and hot water equipment. So your appliances, like gas stoves, ovens, dryers, and fireplaces, aren’t the focus of these regulations.
How Absolute Plumbing, Electrical, Heating & Air Helps
Now that the law is in place, homeowners in Denver and the Front Range are getting used to these new rules and regulations. You don’t need to rush into a decision, but being informed makes all the difference in the end. That’s where Absolute Plumbing, Electrical, Heating & Air comes in.
Our certified technicians will take a look at your current system, explain ultra-low NOx requirements, and walk you through any replacement options. We’ll also break down available rebates, tax credits, and financing options so you can make a confident decision without any sticker shock.
If your system was installed only a few years ago and is running well, we’ll tell you. But if it’s nearing the end of its life, we’ll help you plan your next steps. Call us or schedule a system check online.
Frequently Asked Questions
Here are common questions we hear from concerned customers about Colorado’s new ultra-low NOx furnace law.
Is Colorado banning gas furnaces in 2026?
No. HB23-1161 does not ban gas furnaces or gas water heaters. They just need to meet ultra-low NOx emission limits, but natural gas equipment will remain available from every major manufacturer.
What happens if my furnace breaks down after January 2026?
Your replacement will simply be a compliant ultra-low NOx unit. Absolute keeps current inventory stocked and offers same-day emergency installs across the Denver metro area, so you won’t be left without heat.
Does the Colorado HVAC law cover gas stoves, dryers, or fireplaces?
No. HB23-1161 applies only to gas-fired central furnaces and gas water heaters. Gas stoves, ovens, dryers, and decorative fireplaces aren’t affected by this law.