Water heater requirements in California cover six things every installation has to satisfy: a permit from your local building department, seismic strapping, a properly plumbed temperature and pressure relief valve, code-compliant venting and shut-offs for gas units, lead-free materials on the potable side, and a passing final inspection. New construction adds electric-ready wiring for a future heat pump. Replacements in existing homes do not.
Permits and Inspections
A plumbing permit is required for essentially every water heater installation or replacement in the state. You apply through your city or county building department, and many jurisdictions now handle simple swaps through an online portal. Fees vary. Some cities charge under $50, others well over $100 once issuance and fixture fees are combined.
Permits typically expire within about six months of issuance, and scheduling the final inspection before that deadline is on you. The inspector will check the seismic straps, the TPR valve and its discharge line, venting clearances on gas units, the expansion tank if the system is closed, the drain pan where one is required, and the gas and water shut-off valves. Fail any of those and you fix the problem and schedule a re-inspection.
Skipping the permit is where people get burned. If a water heater that was never inspected causes damage, your homeowners insurance can deny the claim because the work was not code-compliant. Insurers have canceled policies or refused renewal after discovering unpermitted plumbing work. At sale, a buyer’s inspector or appraiser flagging the installation can delay closing or force a retrofit at your expense. The permit usually runs under $200. The downside of not pulling one runs into the thousands.
Seismic Strapping
California requires every water heater, gas or electric, new or existing, to be braced against earthquake movement.1California Legislative Information. California Health and Safety Code HSC 19211 The standard is two heavy-duty metal straps, one in the upper third of the tank and one in the lower third. The lower strap has to sit at least four inches above the controls and drain valve so those stay accessible. Each strap wraps the tank completely and anchors into wall framing.2California Seismic Safety Commission. Water Heater Bracing Requirements Pre-made bracing kits from a hardware store are fine as long as they meet those specs.
Strapping also matters at sale. State law requires the seller of a California home to certify in writing that the water heater has been properly braced, and that certification can be folded into the transfer disclosure statement.1California Legislative Information. California Health and Safety Code HSC 19211 An older unit that was never strapped will need to be brought up to code before or during a sale.
Plumbing Safety Requirements
Temperature and Pressure Relief Valve
Every tank-style water heater has a temperature and pressure relief (TPR) valve, and the California Plumbing Code sets specific rules for its discharge pipe. The pipe runs downhill by gravity with no traps or low spots, terminates unthreaded, and ends between 6 and 24 inches above the floor or finished grade.3IAPMO. 2025 California Plumbing Code If the valve opens under pressure, the water needs a clear, safe path out.
Drain Pan
A drain pan is required whenever the unit sits somewhere a leak could damage the building, such as an attic, an upper floor, or a finished basement. The pan has to connect to an approved indirect waste drain like a floor drain or an exterior line. Do not route the TPR discharge pipe into the pan. The pan handles slow leaks. The TPR valve handles emergency pressure releases, and those need their own discharge path.
Thermal Expansion Tank
If your plumbing has a backflow prevention device or a pressure-reducing valve, it is a closed system. Heated water in a closed system has nowhere to expand, and the pressure spike can damage pipes, fittings, and the tank. The California Plumbing Code requires a thermal expansion tank on any closed water heating system.3IAPMO. 2025 California Plumbing Code A TPR valve that drips constantly is often the first sign expansion is going unmanaged.
Lead-Free Materials
All pipes, fittings, and fixtures that contact potable water must be lead-free. That means a weighted average of no more than 0.25 percent lead on wetted surfaces, and no more than 0.2 percent lead in solder and flux.4California Department of Toxic Substances Control. DTSC Requirements for Low Lead Plumbing Products in California Where dissimilar metals meet, such as a copper line joining a steel tank nipple, use a dielectric union to prevent galvanic corrosion.
Gas Water Heater Rules
Gas units have to vent combustion byproducts to the outdoors. Double-wall metal flue pipe needs at least one inch of clearance from combustible materials, and single-wall connectors need more. The unit also needs adequate combustion air, which in a tight utility closet may require adding vent openings to the room.
Shut-off valves are required on both the cold water inlet and the gas supply line. The gas shut-off has to be accessible without removing panels or covers so it can be turned off quickly in an emergency.
In a garage, the ignition source (pilot, igniter, or burner) has to sit at least 18 inches above the floor, because gasoline vapors and other flammable fumes settle low. Units listed as flammable vapor ignition-resistant (FVIR) are exempt because they handle that risk internally.
Any home with a gas water heater needs carbon monoxide alarms in a central location outside each sleeping area and on every level. If the home does not already have alarms in those locations, adding them is part of the project, and the inspector will check.
Electric-Ready Wiring in New Construction
If you are building a new single-family home and installing a gas or propane water heater, the building has to include electrical infrastructure to support a future heat pump water heater. This mandate applies to new construction only. It does not apply to additions or alterations of existing homes, and it does not apply to a straight replacement of one gas unit with another.5California Energy Commission. 2022 Building Energy Efficiency Standards Beyond that boundary, every water heater sold in the state has to meet federal Uniform Energy Factor minimums regardless of where it goes.
The electric-ready package also includes a condensate drain line near the base of the water heater location, since heat pump units generate condensation. The drain has to allow gravity flow.
Who Can Do the Work
Water heater installation falls within the scope of a C-36 plumbing contractor’s license, which covers water-heating equipment and its associated piping.6California Contractors State License Board. C-36 Plumbing Contractor Licensing Classifications If you are hiring, verify an active C-36 through the Contractors State License Board. Homeowners can do the work themselves under an owner-builder declaration, but you still have to pull the permit, meet every code requirement, and pass the inspection. The standards do not relax for a homeowner.
Rebates
California’s HEEHRA rebate program, funded through the Inflation Reduction Act and delivered through TECH Clean California contractors, offered up to $1,750 for heat pump water heater installations in income-qualified households. As of February 2026, single-family HEEHRA rebates are fully reserved statewide and new applicants are on a waitlist. Rebates remain available for qualifying multifamily properties.7California Energy Commission. Inflation Reduction Act Residential Energy Rebate Programs The federal Energy Efficient Home Improvement Credit under Section 25C expired December 31, 2025 and is not available for units installed in 2026.8Internal Revenue Service. FAQs for Modification of Sections 25C, 25D, 25E, 30C, 30D, 45L, 45W, and 179D Check your local utility as well. Many California utilities run their own rebate programs for efficient water heaters, and those change independently of the state and federal programs.