Sacramento County Homeowners Face New 2025 Water Heater Expansion Tank Requirements That Could Save Thousands in Plumbing Damage

If you’re planning a water heater installation or replacement in Sacramento County this year, there’s critical code information you need to know that could protect your home from costly water damage and ensure your project passes inspection on the first try.

What’s Changed: Understanding Sacramento County’s Expansion Tank Requirements

The California Plumbing Code (CPC) now requires an expansion tank on all closed-loop plumbing systems, and Sacramento County is strictly enforcing these updated regulations. A closed-loop plumbing system is a system that has a backflow preventer and or a backflow device (check valve) installed between the house and the water meter.

This requirement isn’t just a bureaucratic formality—it’s a crucial safety measure. Newer water meters now have a check valve (a closed loop system has been established), meaning most Sacramento County homes now fall under this requirement whether homeowners realize it or not.

Why Expansion Tanks Matter for Your Sacramento Home

When water is heated, it can increase in volume by up to 4%, causing pressure within the plumbing system and affecting standard plastic solenoid valves and other plumbing components. Without proper pressure relief, this expansion can cause serious problems.

The pressure build up can also lead to the T&P valve on the water heater opening and releasing hot water, creating potential safety hazards and water damage. Expansion tanks are designed to absorb the excess pressure and extend the life of your water heater and plumbing system.

When You Must Install an Expansion Tank

Sacramento County requires expansion tanks in several specific situations:

• If there is a check valve, backflow preventer or “other normally closed device that prevents dissipation of building pressure back into the water main”
• When a pressure regulator is installed
• When water system pressure exceeds 80 PSI
• For use on all water heaters from up to 50 gallons, larger expansion tanks for larger water heaters, and for the installation of tankless water heaters

Professional Installation Requirements

Sacramento County doesn’t allow DIY water heater installations. It shall be unlawful for a person to install, remove, replace, or cause to be installed, removed, or replaced a water heater without obtaining a permit from the Authority Having Jurisdiction.

When you need professional Water Heater Installer Sacramento County, CA services, it’s crucial to work with licensed contractors who understand current code requirements. Professional installers must also address additional 2025 requirements including:

• Storage-type tank units are required to have a certified restraint at the top and bottom thirds of the tank for earthquake safety
• The first 5 feet of hot and cold water pipes must be insulated if they are exposed in an unconditioned space
• Bonding of the hot and cold water piping and gas piping with 6 AWG wire gauge, wire, and grounding clamps

Expansion Tank Specifications and Sizing

An expansion tank is a cylinder tank about 2.2 gallons in size, and is typically now required for use on all water heaters from up to 50 gallons. The standard rule of thumb is that you use a 2-gallon expansion tank for standard water heaters up to 50 gallons in capacity, provided the static supply is less than 60 pound-force per square inch (PSI).

Expansion tanks are built with a rubber bag (bladder) inside the tank and is about half the size of the tank itself, this bag is filled with air pressure that should match the pressure of the incoming water into your home’s main water supply piping.

Code Enforcement and Inspection Requirements

In Sacramento, plumbing codes mandate the use of expansion tanks in homes with closed-loop water systems to prevent excessive pressure buildup caused by thermal expansion. Local inspectors enforce these codes to ensure compliance, and homeowners installing new water heaters or modifying plumbing systems must meet these requirements to pass inspections and avoid costly damage.

Each city may decide to implement the plumbing codes differently dependent on the situation. For example, in some areas the city inspector won’t require an expansion tank to be installed as long as there is a working T&P valve present.

Working with Local Sacramento County Professionals

Given the complexity of these requirements and the potential for local variations in enforcement, it’s important to hire a company that knows the latest codes. Companies like CG Plumbing, which serves El Dorado and Sacramento Counties, understand the local requirements and can ensure your installation meets all current standards.

Professional installers familiar with Sacramento County codes will handle permit applications, ensure proper expansion tank sizing and installation, verify all safety requirements are met, and coordinate inspections to ensure code compliance.

Cost of Non-Compliance

Failing to install required expansion tanks can result in expensive consequences. When water heats up, it expands, increasing pressure within the system, which can lead to leaks, pipe damage, or water heater failure. Additionally, unpermitted work can create liability issues when selling your home and may void manufacturer warranties.

Take Action Now

Whether you’re replacing an existing water heater or installing a new system, understanding Sacramento County’s 2025 expansion tank requirements is essential for protecting your investment and ensuring code compliance. Don’t risk costly repairs, failed inspections, or safety hazards by attempting DIY installation or working with contractors unfamiliar with current local codes.

Contact a licensed professional who understands Sacramento County’s specific requirements to ensure your water heater installation is safe, compliant, and built to last. Your home’s plumbing system—and your wallet—will thank you for making the right choice from the start.