What is the Bay Area Zero Emissions Water Heater Rule 9-6 (BAAQMD Rule 9-6) “Essentially Banning Residential Gas Water Heaters” After 12/31/2026
1. What is the BAAQMD “Zero Emissions” Water Heater Rule?
In 2023, the Bay Area Air Quality Management District (BAAQMD) passed Rule 9-6. This rule mandates that starting in 2027, any new water heater sold or installed in the nine Bay Area counties must be a “Zero NOx” (nitrogen oxide) emitting appliance. Effectively, this means a transition from traditional gas water heaters to high-efficiency Electric Heat Pump Water Heaters.
While this is not considered a “Ban On Gas Water Heaters” it means that after 12/31/2026, gas water heaters will no longer be sold in this nine county area – essentially banning gas water heaters. Certain gas units or certain homes may be eligible for a variance to allow a one time emergency gas water heater replacement, knowing that a conversion to heat pump will be required the next time the water heater is replaced.
2. When does rule 9-6 go into effect?
The compliance dates are phased based on the type of water heater and property:
- January 1, 2027: Residential style gas storage water heaters (typical for single-family homes). Including 30, 40, 50, & 75 gallon units – anything unit with more than a 75K BTU Input.
- January 1, 2029: Larger commercial and multi-unit water heaters. This will affect the remaining styles of larger commercial gas water heater tanks.
3. Do I have to replace my working gas water heater right now?
No. You are not required to replace a functioning gas water heater. The rule only applies when your current unit fails and needs to be replaced. However, many homeowners are choosing to switch early to take advantage of current rebates and avoid the “emergency” rush once the ban begins. Additionally, homeowners with older gas water heaters are preventatively replacing units with a gas water heater, allowing homeowners time to convert to a heat pump water heater. This is based on personal homeowner choice and what is best for the current electrical situation.
4. Which counties are affected?
Currently, the rule applies to all nine counties within the BAAQMD jurisdiction:
- Alameda, Contra Costa, Marin, Napa, San Francisco, San Mateo, Santa Clara, Solano, and Sonoma.
However, there is also a state rule that will overlay the air quality management districts rules that will take effect in 2030.
5. What is a Heat Pump Water Heater, and how does it work?
Instead of creating heat through combustion (burning gas), a heat pump water heater pulls heat from the surrounding air and transfers it into the water tank. It’s essentially a “fridge in reverse” and is up to 3 to 4 times more efficient than a standard gas unit.
6. Are there rebates available to help with the cost?
Yes! Because this is a major environmental initiative, there are significant incentives available, however these incentives are on a first come first serve basis. The sooner a homeowner can apply or claim a rebate, the more affordable the conversion will be. Additional rebate funding may become available, but rebates are not guaranteed until they are claimed and approved. Some current incentives include:
- Local Utility Rebates: Programs like TECH Clean California or BayREN often offer $1,000–$3,000+ depending on your area and equipment.
- SWITCHISON.ORG for state and local rebates.
- Note: Water Heaters Only, Inc. can help you identify and apply for the best available rebates in your specific zip code. Call our expert staff and ask about help with a heat pump conversion.
7. Will I need to upgrade my electrical panel?
In some cases, yes. Since you are moving from a gas-powered appliance to a 240Volt electric appliance, a new 240V circuit may be required. Depending on the panel you have now, it may have room to add an additional double pole breaker – if your panel is full, you may need an entire panel upgrade.
The good news is there are also rebates and incentives in certain areas for panel upgrades. As a last resort option, manufacturers have “120V Plug-In” heat pump models that do not require as much electricity. These models can use the power from a standard outlet, and may not require a panel upgrade. Please note that 120V Heat Pump Water Heater recovers (meaning it reheats itself) at much slower rate than the 240V Heat Pump Water Heaters, and may not deliver enough hot water for the households morning showers, but a professional assessment is necessary to see what fits your home and your lifestyle.
8. Why should I call Water Heaters Only, Inc. before 2027?
Waiting until 2027 means you may face:
- Higher Demand: Contractors will be booked out weeks in advance.
- Supply Chain Issues: High demand for units could lead to local shortages.
- Expiring Rebates: Many current high-value rebates are “first-come, first-served.”
Water Heaters Only, Inc. is an expert in the water heating industry, as one of the first water heater specialty companies founded, we have the experience, the knowledge and the expert staff to help guide our customers through the entire heat pump water heater conversion, while also working to assist homeowners with securing the best prices and incentives available. Call to speak with a water heater expert today and let’s figure out what is the best plan of action for your home.
You can also download our Guide to heat pump conversion here (Link to Guide)
One advantage of a commercial
Upgrading to a tankless water heater is also an investment in the longevity of the water heating system. While a typical commercial storage water heater may require replacement every 8 to 12 years, tankless models are designed for longevity, often providing reliable service for 20 years with proper maintenance. This extended lifespan reduces the frequency of costly water heater replacements and minimizes disruption to the business.
Visible
Traditional storage water heaters generally have a lifespan of about 10 to 15 years, while tankless water heaters last about 20 years. So, if an existing storage-tank water heater is over 10 years old or a tankless unit is over 20 years old, it may be time for a replacement, especially if it begins to have ongoing problems. A water heater that requires frequent repairs should also be replaced, as the cumulative cost of these service calls can exceed the cost of installing a new, more energy-efficient water heater.
One of the most obvious
Any evidence of water leakage or moisture around the base of the water heater or its connections is a serious concern. While a minor drip near a connection may be fixable, persistent leaks from the tank body itself can cause extensive property damage if left unaddressed. A professional can determine whether the leak is a simple repair or a sign of a compromised and corroded tank, necessitating a water heater replacement.


The advantages of adding a
While any home can benefit from a hot water recirculating system, there are specific situations and signs that installing one would be particularly advantageous:
Installing a
Knowing the signs of trouble can help people address issues quickly by calling for heat pump water heater repair or replacement. Signs that a heat pump water heater needs professional attention include:
Water heater maintenance involves several crucial tasks designed to extend the unit’s lifespan and ensure safe, efficient operation. One of the most important steps is
Regular maintenance of a water heater translates directly into tangible savings and improved performance. One of the most significant benefits is improved
Tankless water heaters
One of the most appealing