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Why You Need an Expansion Tank for Your Water Heater

Plumber GranvillePurchasing Guide for Water Heaters

Having your water heater in optimal condition should be your top priority if you use this plumbing equipment regularly. Without maintenance, the heating system can easily be damaged or won’t produce the necessary hot water. One of the most ignored additional devices of a water heater is the expansion tank. This article will explain why this particular installation is needed.

What is an Expansion Tank?

The water heater thermal expansion tank hinders any form of sudden change in water pressure and temperature. The specialised tank acts as a repository for excess water volume.

How Does it Work?

This device is very straightforward when it comes to its operating procedure. As the water heater begins to raise the temperature, the water supply starts to expand. This water goes into the expansion tank. When you finally use the heated water through the use of plumbing fixtures, the expansion tank will then disperse the excess water through the pipe system.

Why do I need it?

First of all, we will discuss the basic function of the water heater and how its process affects its system and components. As you already know, a water heater will constantly heat water or as needed–depending on the type of heating system you have. Water behaves differently when exposed to high temperature; it expands its volume. Because the water volume and temperature increase, the tank is forced to expand and contract. This is something that you don’t want to happen since it doesn’t only damage the tank but the entire heating system as well. Constant expansion can force the metal composition of the water heater to alter.

However, it’s the nature or basic function of the equipment that causes this so this always happens. This is when the expansion tank comes in. The expansion tank can help regulate the temperature and water flow. Just think of it as an extra tank that gets rid of excess water. Without the expansion tank, your water heater will continually expand until it becomes less efficient or just break down.

The thermal expansion is even more important for households that have a closed system since its water system only goes one way. Closed systems are very prone to water pressure damage as it can’t shift the water flow to another pipe lining due to its one way system. In fact, some residential and commercial areas even require homes or establishments that have close systems to install expansion tanks. Also, you don’t need to install these extra tanks if you have a tankless system water heating system.


Prices will vary depending on where you live or the set-up issues. However, the installation is pretty straightforward so it’s not really that expensive. Plumbers generally have a good idea on the pricing and proper installation of this equipment so be sure to give them a call. If you plan on purchasing a water heater, it’s better to purchase an expansion tank as well. It can be cheaper to install both at the same time rather than individually purchasing the pieces and installing them.