As of January 1, 2026, Colorado’s new gas water heater regulations are officially in effect. House Bill 23-1161 has changed which gas water heaters can be sold in the state, and many homeowners are only discovering the impact when it’s time for a repair or replacement.
At Altitude Plumbing Solutions, we’re already helping homeowners navigate these changes. Understanding what the law requires, how it affects pricing and availability, and what options you have can make replacing a water heater far less stressful.
What Changed Under Colorado’s Water Heater Law
Colorado now requires that all new gas water heaters sold in the state meet Ultra-Low NOx emission standards. NOx, or nitrogen oxides, are pollutants created during fuel combustion. These emissions contribute to smog and poor air quality, particularly along the Front Range where population density and weather patterns already strain air quality.
This regulation applies to gas water heaters only. Electric water heaters are not affected, and existing gas water heaters already installed in homes do not need to be replaced just because of the rule.
Why Ultra-Low NOx Standards Were Implemented
The purpose of HB23-1161 is to reduce smog-forming pollution and improve overall air quality across Colorado. Ultra-Low NOx water heaters are designed with cleaner combustion systems that significantly reduce nitrogen oxide emissions while still delivering dependable hot water.
Colorado’s standards closely mirror those used in California, where Ultra-Low NOx appliances have been required for years. As environmental regulations continue to expand, these systems represent the direction residential gas appliances are heading nationwide.
What “Ultra-Low NOx” Means for Homeowners
Ultra-Low NOx water heaters must pass strict emissions testing and are engineered differently than traditional gas models. While performance remains strong, these systems are often more complex and may have higher upfront costs.
Several manufacturers already offer compliant models, including Bradford White with residential tank-style units and Navien and Lochinvar with high-efficiency tankless options. Because of the added engineering and certification requirements, pricing can be higher and availability more limited compared to older-style water heaters.
Inventory Exemptions and Real-World Availability
Gas water heaters that were already in Colorado inventory before January 1, 2026 are still allowed to be installed. However, as that inventory continues to sell through, homeowners are increasingly limited to Ultra-Low NOx models.
This has already affected lead times and equipment selection. In some cases, homeowners may have fewer size options or experience longer waits, particularly during peak replacement seasons or emergency situations.
How the New Rules Affect Water Heater Replacement Decisions
Replacing a water heater in 2026 requires more planning than in the past. Equipment selection, budget considerations, and installation requirements all matter more under the new standards.
A professional evaluation helps determine whether an Ultra-Low NOx gas unit, an electric water heater, or a tankless system is the best fit for your home. Factors like household hot water demand, gas and electrical capacity, venting, and long-term operating costs all play a role in making the right choice.
Local Water Heater Experts Serving Parker and Nearby Communities
Altitude Plumbing Solutions proudly serves homeowners throughout Parker, Castle Rock, Lone Tree, Elizabeth, Aurora, and Highlands Ranch. We stay current on Colorado plumbing regulations and manufacturer requirements to ensure every installation meets today’s standards.
If you’re replacing a water heater in 2026 or beyond, we’ll help you understand your options, avoid compliance issues, and select a system that fits your home and budget.
Schedule a water heater consultation today with Altitude Plumbing Solutions and get expert guidance under Colorado’s current water heater rules.
FAQs: Colorado Water Heater Regulations
Do I have to replace my existing water heater because of the new law?
No. Existing gas water heaters already installed in homes are not required to be replaced.
Are electric water heaters affected by the Ultra-Low NOx rule?
No. The regulation applies only to gas water heaters.
Are Ultra-Low NOx water heaters less powerful?
No. They are designed to maintain performance while producing cleaner combustion.
Will water heater prices continue to increase?
Prices may continue to fluctuate as inventory changes and demand for compliant models increases.