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Expansion Tanks: How They Act as a Safeguard for Water Heaters

Hot water heaters seem like a straight forward concept, it heats up the water that runs through your pipes, which provides you with a hot shower. Simple enough, until a problem comes up with your water heater, then questions arise.

Hot water heaters traditionally come in the form of a large tank. These tanks can commonly be found in a household’s garage. When things go wrong, it’s usual the best idea to call a plumber. When an experienced plumber comes out, they may suggest the installation of a new water heater as well as a thermal expansion tank, also known as an expansion tank.

Thermal expansion tanks are installed above the water heater itself. They come in several different sizes depending on the size of the water heater, the amount of hot water needed and the water pressure. When water heats up, it expands, which creates a higher volume and in turn more pressure. The water pressure that is created can have a negative impact on your water heater because the space is limited and the water has nowhere to go. The purpose of the expansion tank is to absorb the excess volume of water that is created during the heating process (or thermal expansion). An expansion tank utilizes a rubber bladder that acts as an air cushion, which allows for the extra water to expand into it instead of being trapped inside the water heater tank.  Thermal expansion tanks are an important process designed to accommodate fluctuations in volume and pressure. This takes an enormous amount of stress off of the water heater and can potentially keep it from exploding.

At Bonney, we strive to provide only the best and knowledgeable service possible. That’s why we send skilled and professional technicians to your home. Part of delivering the best service we can is to make recommendations that we feel will keep our customer safe and healthy. One of the most frequently asked questions we get is: if my old water heater didn’t need it, why would my brand new water heater need it? Today’s plumbing systems work differently than they used to. In the past, the expanding water was able to push back into the plumbing system and the city main line. Now, many cities have added devices called check valves that create a closed system. This means that once the city water passes the water meter into your home, the water cannot flow back into the city system. This closed system allows cities to maintain a close watch on water consumption for every household, but creates a challenging environment for any expanding water. With the water trapped in your home plumbing system, it can expand above a normal working pressure, causing stress on the water heater as well as the rest of your plumbing system. The expanding water can have a damaging effect on pipe valves, hoses, flex connectors and other appliances connected to the plumbing system because it backs up into these places instead of a designated safe area. The addition of an expansion tank can substantially reduce stress and damage to your water heater and overall home plumbing system. For these safety reasons, we recommend an expansion tank installation on every new water heater installation job. In some municipalities, it is actually required when installing a new water heater. If you have questions or concerns, call your local municipality for requirements.