What Is A Boiler Expansion Tank?

image of a boiler with boiler pressure relief tank

Have you ever worried about the condition of your water heater? Maybe you hear a loud noise when you turn the shower off. Perhaps your HVAC professional has told you that the time has come to replace the boiler expansion tank, but you don’t have a clue what this tank is or what it does. No problem. Your boiler expansion tank is a key element of your home’s water heating system or hydronic heating system. In this article, we share some vital information about boiler expansion tanks.

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What Is A Boiler Expansion Tank?

Your water boiler has a main water tank and on top of this main water tank is your expansion tank which is simply an area that allows water to escape as the water in your boiler heats and expands. The boiler pressure relief tank has a diaphragm in the middle that separates the tank into two separate sections — one where expanding water can escape to and one section that provides a cushion of air that can help regulate the pressure that builds when the water in the system is heated.

There was a time when expansion tanks were tanks with a single unit, the improved version is designed with two separate sections in the tank; preventing air from being able to get into the boiler leading to problems with corrosion. An expansion tank helps in both the heating and chilling of the water. They can also play a key role in eliminating some of the common causes of hydraulic shock or water hammers. Continue reading to learn more regarding water hammers as well as the symptoms you might notice.

What Is A Water Hammer?

The term water hammer, also known as hydraulic shock, is simply a fairly common phenomenon that can add additional wear and tear to your water heating system. Have you ever turned off the bathtub or faucet and heard a loud bang? That noise is caused by the flow of water changing directions suddenly which sends out shock waves. This can lead to faster deterioration of the heating system and pipes as well as causing a very annoying sound. To help protect your heating system and avoid damage from the water hammer, a boiler expansion tank can be installed.

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Boiler Expansion Tank Types

There are two options when it comes to boiler expansion tanks: there’s a steel type and a bladder type. We’ll look at each a little closer.

The Steel Type Expansion Tank

image of a steel boiler expansion tank

A steel expansion tank is the type that’s been used for many decades and can usually be found in older homes. This type of tank doesn’t have a diaphragm, so water and air don’t come in contact with one another. Hence the reason a steel tank is used to avoid as much corrosion as possible. This type of tank should also have a window or sight class that allows for easy viewing so the ratio of air to water can be monitored.

The appropriate ratio of air to water will depend on a variety of factors. This can include whether the convectors are made from iron or copper, as well as the size of the tank, and other factors. A steel tank can have problems such as corrosion, resulting from water and air mixing. Other problems can include a faulty gasket or the tank flooding. A professional will be able to determine the best size and type of expansion tank for your water heater or boiler.

The Bladder Expansion Tank

The main difference between a steel tank and a bladder tank is that the bladder expansion tank has a diaphragm designed to separate the air and water in the tank. This can provide a longer lifespan but doesn’t completely eliminate the problem of air inside the system. In a bladder-style tank, the air is separated from the water resulting in the need for the air to be removed. A professional should be sued to ensure the system has the right amount of pressure. An HVAC technician can provide expert guidance as to the size of the bladder expansion tank that’s right for your boiler.

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Do You Have A Boiler Pressure Relief Tank That’s Working Properly?

Have you been concerned about whether or not your expansion tank is functioning the way it should? A very common cause for a malfunction is when the pressure in the chambers of the tank isn’t at the right level. A steel expansion tank is designed with a relief valve that can vent hot water when the pressure gets too high, this clearly indicates there’s a pressure problem in the tank. Looking through the sight glass to check the water level can help you determine if the pressure is off. As for a bladder tank, you can check on the diaphragm’s airside to see if the pressure is too high and if the line needs to have water drained so the bladder is able to refill with air to ensure the right pressure.

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A heating system can have one or multiple boiler expansion tanks. But, few people understand the actual function of these tanks. These handy reservoirs or tanks help regulate the pressure in your heating system as water is heated in the system’s boiler tank. This helps prevent issues with the boiler tank, like overpressurization and water hammer. These tanks can also help protect your heating system, giving it greater longevity. Give Wilcox Energy a call today and get a free quote for installation.

Call Wilcox Energy For Your HVAC NEEDS

Wilcox Energy offers exceptional HVAC service on the southern Connecticut shoreline. Our certified technicians are the best in the industry and are trained to provide exceptional HVAC installations, replacements, repairs, and tune-ups. All of our technicians have the experience and knowledge to provide quality services.

Wilcox Energy guarantees heating and cooling costs that are the most competitive in the area. We offer maintenance services to improve home comfort as well as energy efficiency to reduce home cooling bills. If you need any type of HVAC replacement or repair, we’ll give you our professional opinion as to the option best for your needs and budget. All work comes with a satisfaction guarantee. Give Wilcox Energy a call and schedule your service appointment today. We always provide in-home estimates for free.

Wilcox Energy also offers top-notch service and competitive prices for heating oil deliveries and oil tank installations. We offer a broad range of financing options and delivery plans, which allow you to customize your oil deliveries to meet your specific needs. Contact Wilcox Energy for all of your residential heating needs.

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For more information about heating and cooling systems, be sure to contact Wilcox Energy. You can contact us at (860) 399-6218. We offer a full line of heater and air conditioner repairs, maintenance services, and installations.

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