Flo

Why You Need a Thermal Expansion Tank

Posted on 15/10/2020 by Gabriel Halimi

Have you ever noticed the small tank that sits right next to your water heater? Ever wonder what the heck it actually does? Well, it’s called a thermal expansion tank, and it’s actually kind of a big deal.

The thermal expansion tank does more to protect your home than you might realize. It helps keep your home’s water pressure in check — and water pressure, if left to its own devices, can do some serious damage.

In this article, you’ll learn about thermal expansion and water pressure, and how thermal expansion tanks keep your plumbing system from breaking down.

What Is Thermal Expansion?

Thermal expansion is the tendency for matter to expand in mass or volume as its temperature increases. It’s one of those universal laws of science that applies to just about anything. The biggest victim of thermal expansion in your home is water. Since your home’s water is all being held up in extremely non-flexible pipes, it’s something you might want to know about.

Water heaters are one of the foundational aspects of our modern lifestyle, and one we take for granted quite often. It’s working all the time, heating up water for our sinks, showers and appliances. And every time it kicks on, the water in that tank expands.

Where does that extra water volume go?

You’d think it just flows right out of your house, but it’s not that easy. That’s because most home’s operate on a closed plumbing system, meaning that excess water is essentially trapped in your home.

Closed Plumbing Systems

Plumbing systems are either open or closed. In an open system, water can flow in and out of your home through the water main. If there’s an increase in water pressure due to thermal expansion, water will naturally flow out of the system since the incoming water is flowing at a lower pressure.

In a closed system, this can’t happen. And the reality is that most homes in the U.S. operate on a closed system. There’s a couple reasons for this. The first is that when it comes to municipal water supplies, having an open system could pose a possible public health risk. Sediment and debris from old lead pipes can contaminate drinking water. So home plumbing systems have a check valve to prevent backflow into the municipal supply.

The other reason most homes operate on closed systems is because of pressure reducing valves. Since municipal water suppliers usually pump out water at extremely high pressures, homes have pressure regulators to dial down the water pressure to safer levels. This protects your pipes and fixtures from wear and tear due to too much pressure.

So if water can’t leave your home, how does your plumbing network deal with the excess pressure and volume caused by your water heater? It relies on a thermal expansion tank.

What Is A Thermal Expansion Tank?

Thermal expansion tanks are the unsung heroes of modern plumbing. They give all that extra water a place to go so the rest of your plumbing system can go about its business without having to worry about high water pressure.

A thermal expansion tank is a small tank that is installed on the inlet line going into your water heater. Inside the tank is compressed air and a bladder. The compressed air is pressurized to match your home’s water pressure.

When your water heater fires up and the water in its tank starts expanding, the water pressure starts to exceed the pressure of the compressed air in the expansion tank. That high-pressure water makes its way into the expansion tank’s bladder. As the bladder fills up, the overall water pressure in your plumbing system starts to go back down.

But an expansion tank isn’t foolproof. If your water heater is set too high, there might be so much expansion going on that there isn’t enough room in the expansion tank for all that water. The water heater manufacturers know this, so they put a pressure release valve on their water tanks.

Pressure release valves are the last line of defense for your water heater. They do their job in a more primitive way by simply letting the excess water spill out into a pan — or sometimes just onto the floor.

So why worry about all this? What’s the big deal with high water pressure?

Why You Should Worry About Pressure

You might think that having high water pressure isn’t that big of a deal. The truth is, water pressure is one of the most important aspects of your home’s plumbing system.

When your water pressure is too high, fixtures, appliances and pipes are all put under extra stress. Your toilets, showerheads and faucets are all designed to operate under a certain pressure threshold. Exceed that pressure and they start to break down and need to be replaced.

Having chronically high water pressure can also lead to bigger problems. Small leaks can develop that can go undetected for months if they’re behind walls, above ceilings or under floors. Those small leaks eventually lead to structural damage, rotting out your home’s wood frame and encouraging toxic mold growth.

High water pressure can also lead to sudden pipe bursts that can cause catastrophic damage and loss of property.  This is especially true in the winter, when freezing temperatures can cause ice buildup in pipes that lead to even higher water pressure.

Fortunately, monitoring your home water pressure has come a long way since the days of manual pressure gauges. Smart Water Security Systems like Flo by Moen continuously monitor your home water pressure and flow, and also scan for leaks with daily automatic Health Tests (pressure-loss tests). And all that data is available to you 24/7 on the Flo by Moen app. To learn more about the Flo by Moen Smart Water Security System, click here.

Avoid Common Problems – Expansion Tank Maintenance

Unfortunately, thermal expansion tanks don’t last forever. Most tanks eventually become waterlogged, making them unable to perform their function. Professional plumbers recommend replacing them every five to ten years. Here are a few ways to look after your expansion tank:

  • Watch out for condensation. This can be caused by a waterlogged expansion tank or could just be the result of a very humid climate. Either way, it could pose a danger if your water heater is situated near any electrical devices.
  • Do the “tap test.” Simply tap or knock on your expansion tank and listen to the sound it makes. If it makes a hollow, ringing sound you know there’s still air inside it. If it makes more of a dull sound, it means your tank is full of water and needs to be replaced.
  • Feel the tank. Feel the top and the bottom of your expansion tank. The top of the tank, which should be filled with compressed air, should be cool to the touch. The bottom of the tank, where the water goes, should be warm. If the top of the tank feels the same as the bottom, you know you’ve got a problem.
  • Pay attention to your water heater’s pressure release valve. Remember the pressure release valve? It starts releasing water if there’s too much pressure for the expansion tank to handle. If you notice the release valve is constantly dripping, it could mean your expansion tank isn’t working anymore.
  • Upgrade your tank before it fails. You don’t have to wait until you notice a problem to invest in a new expansion tank. A good rule of thumb is to replace your tank whenever you replace or service your water heater.
  • Replace a faulty tank as soon as possible. If your expansion tank isn’t doing it’s job, your home’s at risk for water damage or, even worse, a water heater explosion. As soon as you notice that something’s not right, get a hold of a plumber and start taking steps to get a new expansion tank installed.

Conclusion

As you can see, thermal expansion is always at work in your home, and your thermal expansion tank is one of your most important plumbing components. It keeps your pipes and fixtures in good shape and protects your water heater. Take good care of it and it will take care of you.

Articles You May Like

5 Best Smart Home Devices to Lower Your Utility Bills
Here’s a list of the five best smart devices to help you lower your footprint and your utility costs at home.
Read More
Posted on by Gabriel Halimi
5 Crucial Ways to Protect Your Home When You’re Gone
Here are a few ways to hack your home to make sure it’s safe, protected, and vacation-ready.
Read More
Posted on by Gabriel Halimi
How to Fix and Diagnose High Water Pressure at Home
We’ll talk about the common signs of having high water pressure and what you can do about it.
Read More
Posted on by Gabriel Halimi
Meet the Flo by Moen Smart Water Security System

In this article, get familiar with the entire Flo by Moen Smart Water Security System. Welcome to smarter plumbing.

Read More
Posted on by Gabriel Halimi
Everything You Need to Know About Thermal Expansion

Thermal expansion is a big deal for a homeowner, and it can cause real damage to your home if you’re not prepared.

Read More
Posted on by Gabriel Halimi
Where is Your Water Main and How Does it Work? Preparing for your Flo by Moen Smart Water Shutoff installation
Your water main is never far from your home and should be fairly easy to find, but it’s always better to know where the main is before leaks occur.
Read More
Posted on by Gabriel Halimi
How to Adjust Your Water Pressure Regulator
In this article, we’ll go over how pressure regulators work and why it’s so important to have one that works properly.
Read More
Posted on by Gabriel Halimi
Why a Smart Home is a Smart Investment

Will a smart home pay for itself in the long run? Will it simplify your life or complicate it? Read on to see how you may benefit.

Read More
Posted on by Gabriel Halimi
Sump Pumps – Usage, Installation, and Troubleshooting

In this article, we’ll explain how sump pumps work and give you some basic maintenance tips to keep your pump running for years to come. We’ll also go over some common issues you might have and show you how to replace an old pump.  

Read More
Posted on by Gabriel Halimi
Protect Yourself From Water Utility Overbilling

Many homeowners have had the unfortunate experience of receiving an unexpectedly high water bill, despite no actual increase in water usage. Here’s how to investigate the problem on your own. 

Read More
Posted on by Gabriel Halimi
The 5 Biggest Water Wasters in Your Home
Unless you have a Flo by Moen Smart Water Shutoff, you’re likely consuming more water than you think.
Read More
Posted on by Gabriel Halimi
12 Plumbing Tips Every Homeowner Should Know

Here are our 12 essential plumbing tips that you should master as a homeowner.

Read More
Posted on by Gabriel Halimi
How to Maintain Your Old Pipes

If you’re looking to avoid tearing up the walls and floors and re-plumbing the whole house, here are a few steps you can take to extend the lifespan of those decades-old pipes.

Read More
Posted on by Gabriel Halimi
10 Tips for Finding Small Water Leaks at Home

But small leaks are a big deal. Here are a couple of reasons you should be paying attention to small leaks.

Read More
Posted on by Gabriel Halimi
Everything You Need To Know About Galvanized Plumbing
In this article, we’ll get into a little background on these older pipes and talk about what they mean for the health of your home and its plumbing system.
Read More
Posted on by Gabriel Halimi
How to Get Insurance to Pay for Water Damage
In this guide, we’ll go over the types of water damage covered by most insurance, important things to consider in your policy, and an outline of the claims process.
Read More
Posted on by Gabriel Halimi
Water Pressure Regulators – Uses, Installation, and Troubleshooting
Your water pressure regulator, also known as a water pressure-reducing valve (PRV), has a huge influence on the strength and longevity of your pipes.
Read More
Posted on by Gabriel Halimi
Repiping a House – Everything You Should Know

Homeowners are always going to face plumbing issues. It’s inevitable. But sometimes, a simple repair isn’t enough — you need to have your entire home repiped. A complete home repipe sounds like a huge job, but you don’t need to be intimidated. In this guide, we’ll go over the entire process — from determining if you need a repipe, to choosing a plumber and what pipe materials to consider. 

Read More
Posted on by Gabriel Halimi
10 Easy Ways to Unclog Your Drains

Here are 10 easy DIY methods to unclog a drain in your home.

Read More
Posted on by Gabriel Halimi
What to Do When a Pipe Bursts (and Before the Plumber Gets There)
If you’re experiencing a pipe burst, call a real plumber. In the meantime, here are a few steps you can take to reduce damage and prevent future leaks.
Read More
Posted on by Gabriel Halimi
Everything You Need to Know About Pressure Reducing Valves

In this guide, you’ll learn how pressure reducing valves work and why they’re such an important part of your plumbing system.

Read More
Posted on by Gabriel Halimi
Here’s What Homeowners Insurance Actually Covers
Choosing the right homeowners insurance is a vitally important decision. Before doing so, it’s important to know what a standard plan does and doesn’t cover in case of disaster.
Read More
Posted on by Gabriel Halimi
Plumbing Tools List – Everything You’ll Need for DIY Projects
Here’s a list of the essential tools for any DIY plumber.
Read More
Posted on by Gabriel Halimi