Colorado ULN Law Starts Jan 1, 2026: Bell Shares How Homeowners Can Save Thousands

Estimated Read Time: 3 minutes

Introduction

If you’re a Colorado homeowner thinking about replacing your furnace or water heater, there’s an important change you need to know about. Beginning January 1, 2026, Colorado’s House Bill 23-1161 introduces new emissions standards for gas-fired central furnaces and water heaters. These Ultra Low NOx (ULN) regulations officially change how furnaces and water heaters are manufactured for sale in our state, and all new units must meet NOₓ (nitrogen oxide) emissions limits.

At Bell Plumbing, Heating, Cooling & Electrical, we want homeowners to be informed early so they can make the best decision for their home and budget. This is a major shift in the market, and acting now could save you thousands.

Understanding Colorado’s Ultra Low NOx (ULN) Emissions Law

House Bill 23-1161 focuses on reducing nitrogen oxide emissions from household heating equipment. Nitrogen oxides are gases produced when fuel is burned in appliances like furnaces and boilers, and these emissions contribute to smog and poor air quality.

Ultra Low NOx furnaces and water heaters use advanced combustion technology to significantly reduce those emissions, often by 65 to 75% compared to older systems. By tightening emissions standards for household heating equipment, the law aims to reduce smog and protect public health, which is particularly important in Denver’s high elevation.

Colorado’s air quality is notably sensitive due to the combination of altitude, dry air, intense sun, and ground-level ozone, which can significantly impact respiratory health. This new standard is designed to help address those challenges by reducing the emissions produced by common home heating systems.

What Changes Starting January 1, 2026

Starting January 1, 2026, only Ultra Low NOx compliant furnaces and water heaters can be manufactured for sale in Colorado. Standard-efficiency and older-design equipment will no longer be produced for our market, which limits the options that homeowners have traditionally relied on.

Here’s what this means in simple terms:

• New equipment options will change: Only ULN-compliant furnaces and water heaters will be available as new units in Colorado.
• Older equipment designs will phase out: Standard-efficiency and older-design models will no longer be manufactured for our market.
• Planning ahead becomes more important: Homeowners may face fewer choices and higher pricing after the law takes effect.

Why Acting Now Could Save You Thousands

Colorado’s Ultra Low NOx regulations are here, and they’ve permanently changed the furnace and water heater market. While the environmental benefits are real, so are the equipment costs. In fact, furnace replacement costs are expected to increase by between 40% and 200%.

If your furnace or water heater is over 10 years old, it might be a good time to look at your replacement options. Bell is still able to secure equipment that was manufactured before the law change, but once those supplies run out, all equipment will be built, therefore, priced for compliance with the new standards.

A proactive replacement plan can help you:

• Avoid higher equipment costs tied to ULN compliance pricing
• Reduce the risk of emergency breakdowns during extreme cold
• Choose your replacement on your timeline instead of being forced into a rushed decision

How Bell Can Help You Prepare

Bell Plumbing, Heating, Cooling & Electrical can help you understand how this new law affects your current equipment and what your best next step should be. Whether you are deciding between repairing an older system or replacing it before pricing changes take full effect, our team can walk you through your options with clear and honest guidance.

When you schedule an evaluation, we can help you:

• Review the condition of your current furnace and water heater
• Understand how the 2026 changes could impact your replacement options
• Get clear, upfront pricing so you can plan with confidence

Final Thoughts

Colorado's ULN law represents an exciting shift towards more sustainable living, with clear financial incentives for those ready to adopt more efficient energy solutions. Bell Plumbing, Heating, Cooling & Electrical stands ready to guide homeowners through this transition, ensuring that they're not only compliant but also maximizing their savings.

Ready to upgrade your home’s energy efficiency? Contact Bell at (720) 740-0350 or visit bellplumbing.com to book a service today.