Bay Area Air District Appliance Rules

The Bay Area Air District (Air District) has amended two rules to reduce air and climate pollution from residential and commercial buildings:

• Rule 9-4: Fan-Type Residential Central Furnaces
• Rule 9-6: Natural Gas-Fired Boilers and Water Heaters

These rules require NEW water heaters and furnaces sold or installed in the Bay Area after the compliance dates (below) to meet zero nitrogen oxide (NOₓ) emission standards. They do not apply to gas stoves, ovens, dryers, fireplaces, or other cooking appliances.

Learn more about Air District rules, the rule making process, and compliance information at the Bay Area Air District Website.

Currently, the only water heaters and furnaces that meet the zero-NOₓ standard are electric. This means that, once the rules take effect, most homeowners replacing a gas water heater or furnace will transition to an electric heat pump model.

Learn more about heat pump appliances here.

Rule 9-6

• January 2028 - Zero-NOₓ standard for residential water heaters (<75 gal)
• January 2033 - Zero-NOₓ standard for large water heaters and boilers (>75 gal)

Find the latest information from the Bay Area Air District on Rule 9-6 here.

Rule 9-4

• January 2029 - Zero-NOₓ standard for residential and commercial furnaces

Find the latest information from the Bay Area Air District on Rule 9-4 here.

In the Bay Area, gas appliances emit more NOₓ—a harmful pollutant linked to asthma, heart attacks, and lung cancer —than light-duty vehicles. 

Air District Rules 9-4 and 9-6 are projected to prevent up to 85 premature deaths and 15,000 asthma attacks annually, avoiding up to $890 million in health-related costs.

Co-Benefits of Modern Electric Appliances

• Better Performance: Electric appliances like heat pumps offer the same or better performance than gas equipment, along with much higher efficiency. 
• Improved Health & Safety: Electric appliances do not use flammable and explosive fuels and don’t produce carbon monoxide and other harmful pollutants.
• Comfort & Reliability: Electric heat pumps will heat your home in the winter and cool it in the summer, helping you handle extreme temperatures with a single device.
• Climate Goals: Electrifying our buildings addresses the third biggest source of greenhouse gas emissions in the Bay Area.

The rules apply ONLY to furnaces & residential water heaters. Cooking appliances, fireplaces, and dryers are not affected.

These rules apply ONLY to NEW appliances. Working appliances can continue to be used.

Many homes can be electrified without a panel upgrade. Electrification can usually be done on 60/100 amps (multifamily/single-family) thanks to power-efficient design strategies.

You will not be left without hot water if your tank fails. Most gas water heaters can be replaced with a heat pump water heater in 1-2 days.

Rebates and incentives may be available. While electrification may entail higher upfront costs, rebates and incentives are available to cover some or all of the difference.

The rules apply to property owners. The Air District is exploring protections to prevent cost burdens from being passed on to renters.

You can weather most power outages. Your home and hot water tank will not cool significantly during typical multi-hour power outages, and many gas appliances require electricity to operate.

The equipment and workforce are ready. Manufacturers have developed innovative new electric appliances, and most contractors are aware of upcoming regulations. In addition, Bay Area counties have been hosting monthly contractor trainings.

• More information is available at Bay Area Air District's Know the Facts webpage.
• Read more about the benefits of electrification at Electrify Marin.
• Search for available incentives and rebates at The Switch is On.