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Water Heater Expansion Tanks: A Guide

As homeowners, we always aim to maintain and enhance the value of our property, ensuring that each component works seamlessly. One such element that deserves your attention is the water heater expansion tank. 

Have you ever wondered, “What exactly is an expansion tank?” or “How does it benefit me?” Then, you’re at the right place. Let’s delve into this lesser-known but highly important aspect of your home’s plumbing system.

What is a Water Heater Expansion Tank?

A water heater expansion tank, as its name suggests, is an additional tank installed within the water heating system. This tank is designed to handle the increase in water volume caused by heating, hence the term “expansion.” It’s not always visible as it can be hidden, but its role in maintaining the integrity of your water heating system is irreplaceable.

When water is heated, it expands. In a closed plumbing system, this creates additional pressure, which can cause various issues, including damage to the water heater, fixtures, and pipes. 

This phenomenon is referred to as ‘water hammer.’ The water heater expansion tank works as a pressure relief valve, accommodating the excess water volume and preventing this unwanted pressure build-up.

How Does a Water Heater Expansion Tank Benefit Homeowners?

  • Protection Against Damage: Water heater expansion tanks offer an effective solution to handle the excess pressure caused by the expansion of heated water. By preventing this pressure build-up, they protect your plumbing system from potential damage, saving you costly repairs down the line.
  • Improved Lifespan of Water Heater: By easing the pressure on your water heater, these expansion tanks help extend the lifespan of the heater itself. With less pressure stress, your water heater can function more efficiently for a longer period.
  • Consistent Water Pressure: Expansion tanks help maintain consistent water pressure throughout your home. This means that your showers, washing machines, and dishwashers receive a steady supply of water at constant pressure, enhancing their functionality and efficiency.
  • Prevention of Potential Health Hazards: Excessive pressure in a water heating system can potentially lead to the release of harmful bacteria into your water supply. By regulating this pressure, water heater expansion tanks help mitigate such health risks.

How to Install an Expansion Tank

Expansion tanks are generally positioned above the water heater on the cold water line, just before it enters the heater. However, the location can be flexible, provided it’s somewhere on the cold water line preceding the water heater. The purpose of the tank is to absorb the extra pressure build-up in the system. Thus, it prevents premature damage to fixtures, such as dripping faucets or running toilets.

The cost of water heater expansion tanks can range from about $40 to nearly $200. The size of the tank is a significant determinant of the price. For the majority of residential installations involving 40- or 50-gallon water heaters, a simple 2-gallon tank suffices.

The process of installation, straightforward and user-friendly, involves a standard 3/4-inch threaded connection. However, it may require the installation of a tee fitting above the water heater, assuming one isn’t already present.

If you plan on employing a professional plumber for water heater installation, inquire about the cost of including an expansion tank in the same service. Often, the additional expense might be minimal, especially if done simultaneously. The benefits of having an expansion tank far outweigh the associated effort and cost.

Remember, while DIY projects can be fulfilling, certain tasks are best left to professionals. This is especially true when it comes to complex plumbing systems.

Do You Need a Water Heater Expansion Tank?

In conclusion, an expansion tank is more than just an ‘add-on.’

It’s an essential part of your home’s plumbing that assures the longevity of your water heater and safeguards the well-being of your entire household.

To find out more about water heater expansion tanks, reach out to us at MET Plumbing LLC. Our expert team is always ready to assist you.

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