May 4, 2023
Water Heaters in Sacramento, CA

Installing a new water heater in your Sacramento, CA home could prove more involved than you think. When homes have closed plumbing systems, their water heaters need an expansion tank. These small, secondary tanks account for the thermal expansion that water undergoes as its temperature rises.

Expansion tanks prevent excess pressure within the water heaters themselves, limit wear and tear, and minimize the risk of tank ruptures. Read on to find out more.


Also known as a closed loop system, a closed plumbing system prevents water from flowing in the opposite direction. When fresh, potable water enters your pipes from the city, there’s only one way for it to get out. This water must flow out of your taps and exit through your drains. It might also pass through your water heater, dishwasher, or washing machine, but it will never return the way it came.

Open loop plumbing systems or open plumbing systems are cheaper, but they’re more wasteful. Any water that flows into your system adds to your water bill. Yes, even if you don’t use it!

With an open loop system, excess or unused water can always reverse its direction and move back into the supply pipes. However, a good portion of this liquid will likely evaporate before you turn your water back on. Even if only a little evaporates, it can add up big time in your water bill. For this and other reasons, most properties have closed-loop systems.


Your water heater tank is constantly filled to capacity. This way, everyone in your home will have access to the hot water they need when they need it. The maximum fill capacity of water heaters accounts for some measure of thermal expansion.

When heated, water can expand by as much as 4% as it nears its boiling point. Without somewhere to go, warm water would place a full water heater under a significant amount of stress. This excess pressure wears your tank down at a rapid rate. It could even lead to tank ruptures or other dangerous events.

An expansion tank provides a separate place for water to go when thermal expansion exceeds a water heater tank’s limitations. This offsets the pressure from the expanding water. As a result, it protects your heater from extra strain.

Having an expansion tank doesn’t mean that you’ll have more hot water for baths or showers. However, it does mean that your water heater will likely enjoy a full and ultimately problem-free lifespan.


In cold weather, expansion can also come from your tank freezing. Of course, this isn’t too likely in sunny Sacramento. Even so, it’s important to note that water heater expansion tanks have a cold-weather purpose too.

Whenever stored water becomes overly heated or cooled, it undergoes pressure changes. As a result, there’s always the risk of having it expand in a way that harms its container.


California Plumbing Code Section 608.3 requires closed-loop plumbing systems to have expansion tanks installed on their water heaters. Installing a water heater in your home without one will keep it from passing essential permitting inspections.

California also requires all water heater installations to be permitted. As a result, we don’t recommend tackling a heater installation on your own. We can make sure that both your water heater and its expansion tank are sized and installed correctly. We also take care of all of the proper permits.

Saving water is a top priority in drought-ridden California. You aren’t likely to find homes in the state that have open-loop plumbing systems. Unfortunately, they create too much water waste to be worth the limited benefits they supply.

As a result, it makes much more sense to use closed-loop systems and expansion tanks. Odds are good that your Sacramento home has a closed plumbing system and a water heater that requires an expansion tank.


Traditional tank-based water heaters can last between 10 and 15 years with proper maintenance. If your home has hard water or other water quality concerns, it might be sooner. Thermal expansion tanks tend to have significantly shorter lifespans. Most models must be replaced once every five to eight years.

When you install a new water heater, you should always have a new thermal expansion tank installed as well. You’ll also need to replace this unit again at your water heater’s half-life.

Fortunately, thermal expansion tanks are among the many features that we check when performing whole-house plumbing inspections. During these visits, we can look for small and developing issues throughout your entire plumbing and water heating system. We are able to catch and correct problems before they result in physical harm or property damage.

We’ve been serving residents of Sacramento, CA, and the surrounding area for more than 30 years. We offer plumbing, furnace, air conditioner, and heat pump service. We also provide HVAC services, water heaters, and indoor air quality solutions. Get in touch with Gallagher’s Plumbing, Heating and Air Conditioning today to find out more about water heater expansion tanks.

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