On March 15, 2023 the Bay Area Air Quality Management District (BAAQMD) adopted amendments to two rules that set zero nitrogen-oxide (NOx) emission standards for new home appliances. They are often called a “furnace ban,” but they work differently from what that name suggests.
What the Rules Say
- Rule 9-4, residential furnaces: a zero-NOx standard for fan-type residential central furnaces starting in 2029.
- Rule 9-6, water heaters and boilers: zero-NOx standards for natural gas water heaters starting in 2027.
- Point of sale: the standards govern equipment sold and manufactured after the implementation date.
- Burnout, not removal: the Air District says the requirements apply only upon burnout of your current equipment.
What It Means for You
You do not have to replace a working gas furnace because of these rules. When your furnace eventually fails after 2029, the new equipment available for sale will have to meet the zero-NOx standard, which in practice points to electric heat pumps. If your furnace is old today, it can be worth comparing a heat pump now rather than replacing in an emergency later.
A Pending Change for Water Heaters
The Air District says its Board will consider changes to Rule 9-6 for water heaters on November 4, 2026, which would add some exemptions and extend the compliance date. Check the Air District’s building appliances page for the current status.
Heat pumps vs. gas furnaces · heat pump installation · book an estimate
Frequently Asked Questions
Is the Bay Area banning gas furnaces?
Not existing ones. BAAQMD set a zero-NOx standard for new residential furnaces starting in 2029; the Air District says it applies upon burnout of your current equipment.
When does the water heater rule start?
Rule 9-6 lists 2027 for natural gas water heaters. The Board is scheduled to consider changes, including an extended date, on November 4, 2026.
Should I replace my furnace before 2029?
Only if it needs replacing. If it is old, comparing a heat pump now lets you plan the switch instead of making it in an emergency.