If you’ve never heard of a water heater expansion tank before, it might sound like nothing more than an accessory for your water heater. Or, maybe it’s some kind of device that expands the capacity of your water heater, so that you can use more hot water.
These are fine guesses, but in actuality, an expansion tank is a safety device that prevents your water heater from being damaged by water pressure. Not just anyone should have one installed, however. Whether you need one depends on how the city has configured your plumbing system.
Don’t worry—we’ll explain what expansion tanks are and if you need one.
Why Do We Need Water Heater Expansion Tanks?
First things first: if you don’t use a storage tank water heater, this post does not apply to you. Expansion tanks were created purely to help with an issue specific to storage tank water heaters.
That specific issue is the fact that the water inside your water heater will expand when heated. This is referred to as thermal expansion.
For example, a tank that holds 50 gallons of cold water will expand to 52 gallons when heated. Since this kind of tank is only rated to hold 50 gallons, you can see where this becomes a problem. Those two extra gallons will put strain on your plumbing system. With enough time, that strain can wear down your water heater, causing it to leak and—in extreme cases—burst!
A water heater expansion tank provides just enough extra volume to alleviate this pressure.
Isn’t My Water Heater Equipped to Deal With This Already?
You may be wondering: If the phenomena of thermal expansion is so easily understood, then why aren’t water heaters in Glendale, AZ already designed to deal with this issue?
Actually, they are! Many water heaters use check valves and temperature-regulator valves to combat this issue. However, the real problem lies in how the plumbing systems are configured between the city and your home. They can either be open or closed water supply systems.
An open water supply system allows the excess water to be pushed back into the city water supply. This alleviates the issue entirely, so you can use your water heater without an expansion tank. In these systems, check and temperature-regulator valves work as intended.
The more likely scenario, however, is that you have a closed water supply system. This is a one-way valve that does not permit water to flow back into the city. Even with the above-mentioned valves in place, it’s not enough to alleviate the pressure created by thermal expansion.
Does My Water Heater Need an Expansion Tank?
The simple answer is to check which kind of plumbing system you have. If your home is integrated with a closed water supply system, then we highly suggest opting for the expansion tank. Don’t underestimate the damage that can be done without one—some cities in the nation have made expansion tanks a legal requirement!
We can help determine if your home needs a water heater expansion tank. Contact The Trusted Plumber today to request an estimate.