The Bay Area Gas Water Heater Rule: What Berkeley Owners Need to Know

Last checked October 24, 2026 · Berkeley Plumbing Services

What is in force today

The Air District adopted amendments to Regulation 9, Rule 6 on March 15, 2023. They set zero nitrogen oxide (NOx) emission standards for small natural gas water heaters, with compliance dates that begin in 2027 and run through 2029 and 2031 depending on size and equipment type. In practice, a zero-NOx water heater is a heat pump water heater or another electric unit, because no gas tank heater currently meets a zero-NOx standard.

The Air District describes the rule as a point-of-sale standard. It governs what can be sold and installed, not what is already in your house.

What is proposed, and when the Board votes

In 2026 the Air District published flexibility and affordability amendments. The Board of Directors is scheduled to consider them on November 4, 2026, and public comments close November 1, 2026, at 6 PM through comments.baaqmd.gov. The Air District says the changes provide some exemptions to the zero-NOx standard and extend the compliance date.

The Air District’s July 2026 draft package gives the details being discussed:

These dates are a draft. The Board can change or reject them on November 4. We will update this page the same week.

The exemptions in the draft

• Emergency replacement: a licensed contractor may install a non-compliant unit temporarily while you wait for a permanent zero-NOx replacement. The temporary unit must come out within 12 months, and the contractor must report it to the Air District.
• Low-income owners: owners enrolled in qualifying assistance programs may install a non-compliant unit.
• Housing cost-burdened owners: owners whose mortgage and property tax payments are at least 28% of gross household income may install a non-compliant unit. They self-attest.
• Space and electrical limits: one-time exemptions for certain tight spaces and inadequate electrical systems.
• Small units: units under 30 gallons may still be sold under a separate standard, because no zero-NOx models that small are available.

To use an exemption, the purchaser or installer registers with the Air District and gets an Exemption Certificate before installation. The draft does not say whether existing gas water heaters can be repaired, so ask your plumber and check the final rule.

What to do now

1. Find your heater’s age. The serial number usually encodes the date. The City of Berkeley notes that a typical gas storage water heater lasts 10 to 15 years.
2. If it is under about 10 years old and working, do nothing. Nothing in the rule forces you to replace a working heater.
3. If it is 10 years or older, plan the replacement before it leaks. Planning lets you compare a heat pump unit calmly instead of choosing in an emergency.
4. Ask about the electrical side. The City says a heat pump water heater typically needs a dedicated 30-amp, 240-volt circuit, and an older panel may need an upgrade. That cost is separate from the heater.
5. Expect permits. The City of Berkeley requires plumbing permits for heat pump water heaters, usually with electrical permits, plus seismic bracing and an inspection before the unit is used.

Heat pump or stay with gas?

A heat pump water heater uses electricity to move heat, not make it. The City says this technology is two to three times more energy efficient than a gas storage water heater. It also needs space (the City recommends at least 700 cubic feet around the unit and a condensate drain), so a small closet can be a problem. See our heat pump water heater page for installation details, and our water heater cost guide for reported prices.