HoldRite Quick Strap 13-Dia Stainless Steel Expansion Tank Mounting Bracket For 5-Gallons Expansion Tank Water Heater. EASTMAN Nevercold 3/4-in-Dia Brass Recirculating Pump System Universal Water Heater. Rinnai 5-in-Dia Plastic Vent Extension Tankless Gas Water Heater. HoldRite Quick Shed 24-Dia Steel Enclosure For 40-Gallons Electric/Gas Tank ...There are some parts that tend to go bad on hot water heaters, including heating elements on electric water heaters and fuel valves on gas water heaters. Plumbing supply stores tha...It prevents the water heater pressure relief valve from opening, saves energy and eliminates a potential safety hazard. It is commonly installed in a domestic hot water system that contains a backflow preventer, a check valve or a pressure reducing valve. Measures: 11 in. L x 7.9 in. W x 11 in. H with 2.1 Gal. tank size, 6 lbs. weight and 3/4 ...The Thermal Expansion Relief Valve can replace a water heater expansion tank because it functions similarly. Both products absorb the excess pressure in the plumbing system created by thermal expansion. ... As plumbers know, the expansion tank equalizes pressure throughout the plumbing system by providing a space for hot water to flow into ... Model # 60022 Store SKU # 1000850984. This Thermal Expansion Tank prevents hot water from back flowing into the cold water line. This tank also prevents hot water from escaping through the pressure relief valve and onto the floor. The thermal expansion tank prevents constant fluctuations in water pressure that damage the heater. Installing a hot water heater expansion tank is a crucial step in ensuring the optimal functionality and longevity of your water heating system. Expansion tanks help to alleviate the pressure buildup that occurs within the water heater as the water heats up and expands. Without an expansion tank, this increased pressure can lead to a range …Watch on. The exact distance that an expansion tank should be from a water heater depends on the size of the water heater as well as the capacity of the expansion tank. Generally speaking, however, it is recommended that expansion tanks be mounted at least a few feet away from the heater, but preferably no more than 8 feet away.A water heater expansion tank is a small tank that is attached to the water supply pipe of the heater. The expansion tank is designed to handle the thermal expansion of water as it heats up in the water heater, preventing excess water pressure. Speaking technically, there is a pressurised area within the expansion tank, sometimes called an air ...May 16, 2020 · Do you have a tank like this mounted somewhere above your water heater? Ever wondered what it is? It's a water heater thermal expansion tank, and it needs to... As a general rule of thumb with expansion tanks, it is better to oversize than to undersize. Plumbing Applications. Therm-X-Trol. Therm-X-Trol expansion tanks are made with non-ferrous materials, which makes them suitable for domestic hot water systems. Characteristics of Therm-X-Trol Expansion Tanks. Secures the water heater and fixturesA water heater expansion tank, also known as a thermal expansion tank, is a small overflow tank that compensates for the thermal expansion of water inside a water heater. As the temperature of water increases, the water expands. Without relief, the pressure inside the water heater will increase, causing damage to valves, plumbing, or …Dec 22, 2021 · A water heater expansion tank looks like a small version of a well pump pressure tank, and it works on basically the same principle. A typical expansion tank is a metal cylinder with a rounded top and bottom that has a volume from 2 to 5 gallons. The potable water expansion tank shall be installed in the cold water service pipe line on the supply side of the water heater (or water storage tank). IMPORTANT: This Watts thermal expansion tank sizing tool should be used as a general guide to sizing thermal expansion tanks. Sizing calculations are wholly dependent on user input and are ...Rheem Residential Water Heaters. With a full line of Rheem ® tank and tankless water heaters to choose from, there’s sure to be one that’s the right fit for your family. Whether you need high water delivery or low energy costs—or both, we have your next water heater. Be sure to browse our impressive line of sustainable, high efficiency ... Hot water expansion TPR valve leak cause & cure. This article explains hot water thermal expansion that can cause leaks, drips, or discharges from pressure relief valves, temperature/pressure relief valves, or TP valves found on heating boilers, water heaters. We explain how to find and fix leaky relief valves on hot water heating systems. The Short Answer Is: Water heater expansion tanks, also called thermal expansion tanks, are small but significant devices that help regulate the pressure in water heaters …Tank Water Heaters. A traditional tank-style water heater costs $1,000 to $1,500, while a high-efficiency or hybrid style costs up to $2,500 with installation. Tank-style heaters keep the water hot, so it’s ready when you need it. They’re great options for: Cold climates. Homes without gas. Homes with high water demands. Tankless Water Heaters5 days ago · Going without a water heater expansion tank is risky. Although, many water heaters don't have an expansion tank, we highly recommend adding one. It'll protect your plumbing, appliances and your water heater. Overflowing hot water can cause the pressure in the water tank to rise to dangerous levels, which may result in the components breaking. DIY - How to Replace Hot Water Expansion Tank. Berry Meherg. 3.44K subscribers. Subscribed. 471. 96K views 4 years ago. Amazon Utilitech 2-Gallon …The Rheem Performance Platinum 50 Gal. Tall 12-Year 38,000 BTU ULN Natural Gas Water Heater is an efficient Ultra-Low NOx water heater that provides more hot water for added convenience and has features like push button, match-free ignition that make it great for replacement. Provides ample amount of hot water for households with 3 to 5 people.Do you have a tank like this mounted somewhere above your water heater? Ever wondered what it is? It's a water heater thermal expansion tank, and it needs to...Expansion Tank Mounting Bracket for Hot Water Heater,Thermal Expansion Tank Holder with 2 Earthquake Straps,Support 5-Gallon Hot Water Tanks up to 13 inches in Diameter-1 Set. 4.8 out of 5 stars. 5. 50+ bought in past month. $16.99 $ 16. 99. 5% coupon applied at checkout Save 5% with coupon.Consumer Reports is a trusted source for unbiased reviews and ratings on various products, including hot water heaters. When it comes to making a decision about which hot water hea...Typical Expansion Tank Sizes for a Cast Iron Radiator type typical residential heating system. For a 100 MBTUH boiler you'd use either an Amtrol Extrol #60 or an Amtrol Fill-Trol #111. For 125-150 MBTUH you'd use an Amtrol Extrol #90. For a 175-200 MBTUH boiler you'd use an Amtrol Extrol #SX30V.1 lb (0.45 kg) of water flashed into steam > 750 000 ft lb f (100 000 J) Expansion tanks are in general designed as. open tanks. closed compression tanks. diaphragm tanks. Net expansion volume of water when heated can be expressed as. V net = (v 1 / v 0 ) - 1 (1) V net = expansion volume of water ( ft3 , m3 ) v 0 = specific volume of water at ...PlumbingOnline.ca is Canada’s top customer-rated online supplier of expansion tanks. Our quality expansion tanks are a required when installing closed water heating ... A standard fifty-gallon unit expands to fifty-two gallons when heated to 120 degrees Fahrenheit, causing the volume of expanded water to rise to dangerous levels. Without a place to accommodate the increased liquid, it pushes out on the hot-water tank’s valve, fittings, gaskets and spigots. Hot water heater tanks are not designed to expand so ... There are some parts that tend to go bad on hot water heaters, including heating elements on electric water heaters and fuel valves on gas water heaters. Plumbing supply stores tha...DESIGN: The tank is designed to prevent hot water from back flowing into the cold water line, or escaping through the pressure relief valve OPTIONS: This thermal water expansion tank is available in varying capacity of 2 gallons and 4. 5 gallons of water; choose as per requirementDIY - How to Replace Hot Water Expansion Tank. Berry Meherg. 3.44K subscribers. Subscribed. 471. 96K views 4 years ago. Amazon Utilitech 2-Gallon …When a hot water expansion tank works correctly, you will probably see no problems with leaks and other issues. It is simpler to understand the signs of expansion tank failure. If your hot water expansion tank is failing, the following will occur. The relief valve drips during the water heater recovery period, despite no water usage.User notes: About this chapter: Chapter 28 contains regulations concerning the safety of water heating units and hot water storage tanks. Heated potable water is needed for plumbing fixtures that are associated with washing, bathing and kitchen activities. Heated water is commonly stored in pressurized storage tanks that must be protected ...Apr 29, 2021 ... Expansion tank installation on a water heater? When do you need a thermal expansion tank? In this video, I am explaining what an expansion ... As water heats inside the water heater and exceeds the capacity of the tank, the overflow rushes into the expansion tank. When an expansion tank is installed, the extra water volume automatically rushes into the tank. This lowers the water pressure inside your water heater to safe levels, protecting your tank (and other water appliances) from ... Typically a Thermal Expansion Tank is a small metal tank - usually either 2.1 gallons or 4.5 gallons. The ST-5 has a tank volume of 2 gallons and is 8" in diameter by 13" high. Its is constructed of stainless steel with stainless steel connections. The ST-5 offers a maximum working pressure of 150 PSI with a factory pre-charge of 50 PSI and a ...The expansion tank is a small cylindrical tank that is connected to the water heater. Its primary function is to absorb the excess pressure created by the expanding water, thus protecting the integrity of the water heater and preventing potential leaks, bursts, or damages to the plumbing system.In this video, I am explaining what an expansion tank is, what does it do, when do you need it, and how to install one yourself on your hot water heater. …Mark and drill on the wall where the mounting brackets will go. • Cut the inlet pipe and prepare threads on the two ends. Install the tee fitting using the pipe wrench and ensure to use the pipe joint compound and Teflon tape to avoid any leaks after installing the tank. • Lastly connect the expansion tank to the tee fitting.However, when water is heated, its volume expands (this is called thermal expansion). When the water volume expands, it puts extra pressure on the tank. Over time, after continuous expanding and contracting, the tank will weaken (think of bending a paper clip back and forth—eventually it will break). And that’s where an expansion tank comes in.The number one warning sign that your water heater could explode is a leaky T&P Valve. When too much pressure builds inside the tank, the temperature & pressure relief valve can discharge hot water. A leaky valve or a valve that routinely releases is a tell-tell sign a problem exists. This T&P valve will leak due to proper operation if too much ...5 days ago · Going without a water heater expansion tank is risky. Although, many water heaters don't have an expansion tank, we highly recommend adding one. It'll protect your plumbing, appliances and your water heater. Overflowing hot water can cause the pressure in the water tank to rise to dangerous levels, which may result in the components breaking. Feb 22, 2024 · Types of Water Heater Expansion Tank. Expansion tanks range in price from $40 to $200 depending on what material they are made from. Newer models are made with a rubber bladder that is able to ... Shut the water off at the water main. Using a bucket, drain the hot water heater just enough to get below the pipes and the top of the tank. Use copper pipe and push fittings to connect the expansion tank. Cut the cold water line above the tank using a pipe cutter, then push both ends of the pipe into both sides of the push T fitting.Water heater expansion tanks are necessary for closed water supply systems to manage thermal expansion and protect pipes. ... Once the system has heated up, test your hot water. How Much Do Expansion Tanks Cost? Expansion tanks typically cost between $40 and $70 . When considering your budget, you should decide whether …Amtrol ST-5 water heater expansion tank is an excellent option for smaller homes or households with a hot water heater that's less than 50 gallons in size. It uses a bladder-style expansion vessel constructed from high-quality stainless steel for durability and to reduce corrosion.By John Smith October 22, 2023. Do you ever wonder about that mysterious tank next to your water heater? If your water heater has a small tank attached to it, that’s an …Appropriate fittings. Now, go along with these step-by-step guidelines to install an expansion tank: Step 1. Turn off the Water Supply. Locate the shut-off valve for the main water supply to your tankless water heater. Then, turn the shut-off valve clockwise to shut off the water supply to your tankless unit.The expansion tank is designed to handle the thermal expansion of water as it heats up in the water heater. Sort by default ...Typically a Thermal Expansion Tank is a small metal tank - usually either 2.1 gallons or 4.5 gallons. The ST-5 has a tank volume of 2 gallons and is 8" in diameter by 13" high. Its is constructed of stainless steel with stainless steel connections. The ST-5 offers a maximum working pressure of 150 PSI with a factory pre-charge of 50 PSI and a ...The Rheem Performance Plus Electric Tank Water Heater is well-equipped to supply hot water for showers, washing hands, or doing dishes. This 50-gallon model is the right size for a family of 3 to 5 individuals, and it comes with a 9-year warranty for peace of mind.While electric water heaters aren’t as energy-efficient as gas versions, this …Expect to pay anywhere from $40 to $200, or about $120 on average, for a water heater expansion tank. The price varies based on the tank size. On average, residential homes with 40- to 50-gallon water heaters use a …Size. Most smaller homes will need a 2-gallon expansion tank, which costs $40 to $60. A 4-gallon expansion tank costs between $60 and $90, while 4.4- and 4.8-gallon expansion tanks range between $60 to $140. For tanks over 5 gallons, you can expect to pay $140 to $200 for the tank alone. Water Heater Size (gal)Install the Tank: Wrap plumber’s tape around the bottom of the tank’s connector. Then place a tee fitting on the connector and tighten it with a wrench (there’s usually a ½ or ¾ inch threaded fitting on the tank to join it with the cold-water supply). Don’t …The ZEP12 is a 4.8 gallon tank and is perfect for use with hot water tanks from 60 - 100 gallons. If you have a 120 gallon hot water heater you may be able to use the ZEP12 as well. Check you tank specifications, temperatures and water pressure before purchasing. The set point for this type of tank is 150°F.Their 7.4-gallon expansion tank is an affordable, high-quality option for people with larger homes who need an expansion for a hot water heater that is larger than 50-gallons. This is a diaphragm system that helps to reduce energy and water waste while also reducing built-up pressure that can result in closed systems. Water heater (hot water cylinder) expansion tanks such as the 2 1/2 gallon expansion tank shown here from Falcon Stainless, Inc., is sold by Amazon and is intended to accomodate expansion in potable water or domestic hot water supply heating systems. [Click to enlarge any image] An expansion tank or expansion vessel is a small tank used to protect closed water heating systems and domestic hot water systems from excessive pressure. The tank is partially filled with air, whose compressibility cushions shock caused by water hammer [citation needed] and absorbs excess water pressure caused by thermal expansion. [1] 1 lb (0.45 kg) of water flashed into steam > 750 000 ft lb f (100 000 J) Expansion tanks are in general designed as. open tanks. closed compression tanks. diaphragm tanks. Net expansion volume of water when heated can be expressed as. V net = (v 1 / v 0 ) - 1 (1) V net = expansion volume of water ( ft3 , m3 ) v 0 = specific volume of water at ... Therm-X-Trol Water Heater Expansion Tank for Tankless Water Heaters. Add to Cart. Compare $ 59. 85 (114) Model# ET-30. Watts. Series ETX Non-Potable Water Expansion Tank. Perform a Quick Flush. Before you shut off the water, connect a garden hose to the drain valve and try and flush the water heater tank a bit while the water pressure is on. To do this, open the drain valve for a few seconds and then close it again. The pressure will blow out any sediment stuck in the valve and help the tank drain faster.A water heater expansion tank protects your plumbing system's fixtures and pipes by preventing excessive water pressure as the water heats up. You need one …Here are five key points about expansion tanks:; 1. Purpose: Expansion tanks are designed to prevent pressure buildup in plumbing and heating systems. When a system heats up, the hot water expands, creating an increase in pressure. An expansion tank allows the system to accommodate this expansion, preventing damage to the …Where a storage tank-type water heater or a hot water storage tank is installed in a location where water leakage from the tank will cause damage, the tank shall be installed in a galvanized steel pan having a material thickness of not less than 0.0236 inch (0.6010mm) (No. 24 gage), or other pans approved for such use.The Thermal Expansion Relief Valve can replace a water heater expansion tank because it functions similarly. Both products absorb the excess pressure in the plumbing system created by thermal expansion. ... As plumbers know, the expansion tank equalizes pressure throughout the plumbing system by providing a space for hot water to flow into ...Model # 60022 Store SKU # 1000850984. This Thermal Expansion Tank prevents hot water from back flowing into the cold water line. This tank also prevents hot water from escaping through the pressure relief valve and onto the floor. The thermal expansion tank prevents constant fluctuations in water pressure that damage the heater.A water heater expansion tank or thermal expansion tank is a safety device that can help minimize the risk of pressure …The Thermal Expansion Relief Valve can replace a water heater expansion tank because it functions similarly. Both products absorb the excess pressure in the plumbing system created by thermal expansion. ... As plumbers know, the expansion tank equalizes pressure throughout the plumbing system by providing a space for hot water to flow into ...Consumer Reports is a trusted source for unbiased reviews and ratings on various products, including hot water heaters. When it comes to making a decision about which hot water hea...Water heater expansion tanks are necessary for closed water supply systems to manage thermal expansion and protect pipes. ... Once the system has heated up, test your hot water. How Much Do Expansion Tanks Cost? Expansion tanks typically cost between $40 and $70 . When considering your budget, you should decide whether …A water expansion tank acts as a bladder that takes in the excess water from the hot water heater so that the pressure doesn’t keep building. A water heater …1. Shut the cold water supply off and relieve water pressure. 2. Install a pipe tee with a 3/4" NPTF threaded connection. 3. Thread the tank into the tee using pipe sealing tape or paste. 4. Open the cold water supply and check for leaks. INSTALLATION MANUAL FOR WATER HEATER EXPANSION TANK Please read the following instructions carefully.Secures expansion tank to wall. Galvanized and stainless steel construction. Supports tanks up to 13 in. Dia. Supports tanks up to 5 Gal. Includes mounting bracket, 2 support straps and mounting screws. Quick-release stainless steel bands. Fast and easy installation. Takes load weight off pipes. HOLDRITE quick strap brand.The cost of an expansion tank, including installation, will run you somewhere between $100 and $400 depending on what kind of water heater you have and what must be done to accommodate the added tank. If you are living in a home with high water pressure, this cost may well be nominal compared to what it may cost overall to address repeated ...The pressure should be adjusted to match the water pressure in your home. Remember to always rely on a professional for installation. 2-gallon thermal expansion tanks. Factory precharged at 40 psi. 3/4-inch MIP connection. For 30-gallon to 50-gallon water heater tanks. Dimension of 12.4-inches x 8.3-inches. 304-stainless steel fittings.DESIGN: The tank is designed to prevent hot water from back flowing into the cold water line, or escaping through the pressure relief valve OPTIONS: This thermal water expansion tank is available in varying capacity of 2 gallons and 4. 5 gallons of water; choose as per requirementA water heater expansion tank, also known as a thermal expansion tank, is a small overflow tank that compensates for the thermal expansion of water inside a water heater. As the temperature of water increases, the water expands. Without relief, the pressure inside the water heater will increase, causing damage to valves, plumbing, or …Then see HOT WATER EXPANSION TANKS - cure the problem of leaks in heated hot water systems, calorifiers, water cylinders. On 2020-05-27 by Mike . The T/P relief valve on my hot water heater is weeping about 1 cup of water every time it heats.In today's video, we talk about the importance of having an expansion tank installed on your water heater. These tanks are very helpful in extending the lif... Instead of storing water, though, the Thermal Expansion Relief Valve releases it, solving some of the problems that come with using an expansion tank. Common Expansion Tank Problems. While expansion tanks are required by code in most closed-loop water heater systems, they have a reputation for failing. Common expansion tank issues include: Water heater expansion tanks regulate water pressure in a hot water system to prevent damage to plumbing and appliances in a home. Steel expansion tanks were used until the mid-to-late twentieth century, while newer diaphragm tanks occupy modern water heater installations. Since 2006, all original and replacement water heater systems have been … Step 2: Determine the size of your thermal expansion tank. For housing, an expansion tank of 2 to 5 gallons is usually used. If you are not sure, it is better to install larger sizes. The pressure relief valve is discharged because the pressure is too high. How They Work. A single-family storage water heater offers a ready reservoir -- from 20 to 80 gallons -- of hot water. It operates by releasing hot water from the top of the tank when you turn on the hot water tap. To replace that hot water, cold water enters the bottom of the tank through the dip tube where it is heated, ensuring that the tank ...It was less than 4 years old at the time. Plumber said, well you don't have an expansion tank so every time the water heater runs the pressure builds up ...For example, the closed tank has a pressure of 14.7 psia. As the hydronic hot water pressure increases above 14.7 psia, the hydronic hot water will flow into the expansion tank. On the other hand, say the bladder/diaphragm is pressurized to 25 psig, then hydronic hot water will only enter the tank when the hydronic hot water exceeds 25 psig.Where a storage tank-type water heater or a hot water storage tank is installed in a location where water leakage from the tank will cause damage, the tank shall be installed in a galvanized steel pan having a material thickness of not less than 0.0236 inch (0.6010 mm) (No. 24 gage), or other pans approved for such use.As water heats inside the water heater and exceeds the capacity of the tank, the overflow rushes into the expansion tank. When an expansion tank is installed, the extra water volume automatically rushes into the tank.This lowers the water pressure inside your water heater to safe levels, protecting your tank (and other water appliances) from damage. About This Product. Built with heavy-duty butyl diaphragm system to absorb the expansion of water volume and help prevent dangerous pressure build-up. This Everbilt Expansion Tank will absorb pressure increases when properly installed on your closed water system. Most local codes now require an Expansion Tank on residential closed water systems. Dec 16, 2019 ... Can a expansion tank be used to protect a hot water heater? YES. Dose it need to be thermally listed? Not really if on the cold water feed ...Hot Water Boiler Expansion Tanks. The ratio of water to the air inside the steel expansion tank is optimal at 2/3rds water to 1/3 air. Tanks not equipped with a site glass need an Airtrol fitting. Located on the bottom of the expansion tank is a fitting. It has an air bleeder on the bottom of it.
The standard rule of thumb is that you use a 2-gallon expansion tank for standard water heaters up to 50 gallons in capacity, provided the static supply is less than 60 pound-force per square inch (PSI). How Do Water Heater Expansion Tanks Work With Temperature Relief Valves? Safety is an important consideration when installing water …. True crime tv shows
The cost of an expansion tank, including installation, will run you somewhere between $100 and $400 depending on what kind of water heater you have and what must be done to accommodate the added tank. If you are living in a home with high water pressure, this cost may well be nominal compared to what it may cost overall to address repeated ...Jun 8, 2023 ... Designed to handle the thermal expansion of water as it heats up in the water heater, the expansion tank plays a vital role in maintaining safe ...Apr 24, 2023 ... The annoying drips that is found near the hot water tank could be sign of a bigger issue. It is always good to check your hot water pressure ...A water heater expansion tank is a small tank that is attached to the water supply pipe of the heater. The expansion tank is designed to handle the thermal …Jul 10, 2019 · As mentioned above, a water heater expansion tank is a safety mechanism that reduces possible pressure damage to your plumbing system. It is sometimes called a thermal expansion tank and is often required by law for most major North American cities. Because water naturally expands when it is heated (a process is known as thermal expansion ... The expansion tank of a water heater is a minor yet vital component that safeguards your home from potential damage due to excess pressure in your water system. When the water heats up in various parts of your home, like the kitchen or bathroom, it expands and creates pressure. An expansion tank acts as a safety net, absorbing this excess water ...The purpose of a thermal expansion tank is to alleviate the pressure buildup caused by the expansion of heated water. Without it, excess pressure can lead to ... tankRo RO132-TNK RO Water Filtration System Expansion Tank 4 Gallon Capacity – NSF Certified – Compact Reverse Osmosis Water Storage Pressure Tank 1/4" Tank Ball Valve. 1,836. 200+ bought in past month. $4248. FREE delivery Sat, Feb 17. Or fastest delivery Fri, Feb 16. Small Business. Pre-pressurize the tank. Most expansion tanks come pressurized to 12 – 40 psi, but before you install the tank you have to match the system pressure. Start by removing the protective cover from the air valve on the tank. Use a tire gauge to check the pressure. Use a bicycle pump, or compressor, to fill the tank to match the system …Want to know how to clean a water softener resin tank? Check out our guide on How to Clean a Water Softener Resin Tank now and find out! Advertisement For those homes that are on a...Dec 16, 2019 ... Can a expansion tank be used to protect a hot water heater? YES. Dose it need to be thermally listed? Not really if on the cold water feed ...As a general rule of thumb with expansion tanks, it is better to oversize than to undersize. Plumbing Applications. Therm-X-Trol. Therm-X-Trol expansion tanks are made with non-ferrous materials, which makes them suitable for domestic hot water systems. Characteristics of Therm-X-Trol Expansion Tanks. Secures the water heater and fixturesA water heater expansion tank is a small tank that is attached to the water supply pipe of the heater. The expansion tank is designed to handle the thermal expansion of water as it heats up in the water heater, preventing excess water pressure. Speaking technically, there is a pressurised area within the expansion tank, sometimes called an air ...The cost of an expansion tank, including installation, will run you somewhere between $100 and $400 depending on what kind of water heater you have and what must be done to accommodate the added tank. If you are living in a home with high water pressure, this cost may well be nominal compared to what it may cost overall to address repeated ...Expansion tanks are safety devices connected to the cold water supply that helps control the thermal expansion of hot water inside a water heater. When …May 16, 2020 · Do you have a tank like this mounted somewhere above your water heater? Ever wondered what it is? It's a water heater thermal expansion tank, and it needs to... .