1. Leaking expansion tank. 2. Tank pressure loss. 3. Tank pressure too high. 4. Air blockage. 5. Condensation on outside of tank. 6. Tank needs recharging. 7. …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. 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 ... 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 over tighten the connector as this can damage it.This is because the water meters come with check valves which create a closed-loop system. Check with your city's plumbing inspector to be sure of the ...Water Heater Expansion Tank Cost Breakdown. The main factors that influence the cost of installing a hot water heater expansion tank are materials—including the size and type of tank you install—and labor. Size. Most smaller homes will need a 2-gallon expansion tank, which costs $40 to $60.Factory pre-charged at 40 psi. Certified with cUPC and NSF 61 compliant. Brass air charging port with O-ring seal. 16-Gauge cold rolled steel shell. High quality coating prevents corrosion. 100% butyl rubber diaphragm lined with polypropylene. Maximum pressure of 150 psi. Maximum temperature rating of 200 degree F.The size needed for your expansion tank is determined by the size of your home's water heater. Expansion tanks are available in 2-gallon and 4.5-gallon sizes. A 2-gallon tank will be appropriate for water heaters up to 50 gallons. An adequately sized tank should have a volume that equals 2% to 5% of the water volume within the system.Thermal Expansion Tank Sizing. Residential Commercial. Water Heater Size. Select 40 50 60 80 120. Gallons. Approx. Temp Setting. Select 120 140 160. °F.Overview. Expansion tank for heater overflow works on heaters up to 50 gallon. Powder coated interior shell protects against corrosion, assures long trouble free life. Exterior powder coat paint for long life and anti-corrosion, certified to automotive ASTM standards. Proper tank sizing is critical to the performance of your water heater.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 …Looking for high-quality water heating solution? Review the 5-Gallon Hydronic Expansion Tank from A.O. Smith.TO PROPERLY SIZE A WATTS SERIES ETX, ETSX, ETA or ET-RA NON-POTABLE WATER EXPANSION TANK: The set pressure of the boiler fill valve. 12psi Air Charge is Standard. The set pressure of the relief valve. NOTE: The lowest setting of the aquastat. NOTE: The maximum setting of the aquastat. MAX.HIGHCRAFT GUU34 Thermal Expansion Tank for Hot Water Heater Carbon Steel Almond Color Holds 4.8 Gal, 4.8 Gallons. 4.7 out of 5 stars 85. $88.89 $ 88. 89. FREE delivery Sat, Dec 2 . Only 4 left in stock - order soon. Duda Energy ExpTank-036V-PW 36 L/9.5 gallon Blue Expansion Tank for Wells & Domestic Hot Water Supply Tank Thermal Pressure ...According to instruction sheet, the max psi aloud by code and for this tank is 80psi. The water pressure coming into house averages between 68-72 psi. I know that's kind of on the high side, average house has around 50-55psi coming in from main. It's been like that forever, haven't blown any pipes apart yet.About This Product. This expansion tank controls thermal expansion of water in open domestic hot water supply systems. It absorbs the increased volume of water generated by the hot water heating source. Its' pre-pressurized steel tank uses an expansion membrane to prevent air/water contact for long system life.Apr 11, 2014 · Expansion Tanks on the How-It-Works series.Expansion tanks are critical components to your Plumbing and Hydronic Heating systems because they prevent your pu... 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 ...To check the gas level in your propane tank, take a cup of steaming water and pour it over the side of your tank. Next, feel the tank from top to bottom, and look for the point whe...5-Gallon Hydronic Expansion Tank. Model PMET 5. Capacity (Gallons) Interior powder coating is permanently bonded to the tank shell for ultimate protection on the water side of the water heater expansion tank. Heavy duty butyl rubber diaphragm ensures long life. Maximum working pressure 100 PSI.2. Water expanding into the pressure tank due to thermal expansion will register as flow (phantom flow). I do that. Small amount of extra flow is recorded by the softener, if your calculations are that critical. To avoid #1 and #2 totally, add a check valve at the output of the softener, and add a thermal expansion tank.When it comes to hot tubs, one of the most important pieces of equipment is the cover. Not only does it keep out dirt and debris, but it also helps maintain the temperature of the ...Maximum working pressure 100 PSI. Positive lock retention system controls compression in the diaphragm connection, eliminating air loss or water leaks in hot water expansion tank. Corrosion-resistant metal air valve. 1-year limited warranty. A. O. Smith offers potable & hydronic expansion tank models, ranging from 2 to 14 gallons.The pre-pressurized steel tank features a durable expansion membrane that prevents contact of the water with the air in the tank. This rugged diaphragm minimizes loss of the air change and ensures long and trouble-free life for …2. Water expanding into the pressure tank due to thermal expansion will register as flow (phantom flow). I do that. Small amount of extra flow is recorded by the softener, if your calculations are that critical. To avoid #1 and #2 totally, add a check valve at the output of the softener, and add a thermal expansion tank.The expansion tank is designed to handle the thermal expansion of water as it heats up in the water heater, preventing excessive water pressure. If water pressure gets to high it can damage valves in plumbing fixtures, joints in supply pipes and the water heater itself. Expanding water from the water heater flows into the expansion tank ...According to instruction sheet, the max psi aloud by code and for this tank is 80psi. The water pressure coming into house averages between 68-72 psi. I know that's kind of on the high side, average house has around 50-55psi coming in from main. It's been like that forever, haven't blown any pipes apart yet.1. Leaking expansion tank. 2. Tank pressure loss. 3. Tank pressure too high. 4. Air blockage. 5. Condensation on outside of tank. 6. Tank needs recharging. 7. …Apr 25, 2023 ... An expansion tank is only required when. 607.3 Thermal expansion control. Where a storage water heater is supplied with cold water that passes ...Apr 11, 2018 · Hydronic Hot Water Systems. This calculator covers the design and selection of a hydronic hot water expansion tank. The expansion tank is a part of an overall hot water system that often includes a hot water generator (fuel fired boiler), piping, valves/fittings, water treatment, hot water coils (air handling units and fan coil units) and hot water pump(s). The expansion tank is designed to handle the thermal expansion of water as it heats up in the water heater, preventing excessive water pressure. If water pressure gets to high it can damage valves in plumbing fixtures, joints in supply pipes and the water heater itself. Expanding water from the water heater flows into the expansion tank ...Item # 963318 |. Model # LET2. 189. Get Pricing & Availability. Use Current Location. Expansion tank for heater overflow works on heaters up to 50 gallon. Powder coated …Thermal Expansion Tank Sizing. Residential Commercial. Water Heater Size. Select 40 50 60 80 120. Gallons. Approx. Temp Setting. Select 120 140 160. °F.This is because the water meters come with check valves which create a closed-loop system. Check with your city's plumbing inspector to be sure of the ...Expansion Tanks on the How-It-Works series.Expansion tanks are critical components to your Plumbing and Hydronic Heating systems because they prevent your pu...The purpose of a Thermal Expansion Tank is to act as an overflow for the excess water created by the water heating, maintaining safe expansion pressure. The ... 1. Regulate pressure and reduce fluctuations. The first reason why it is important to have an expansion tank is to regulate the pressure. If the pressure increases in the system, in the worst-case scenario, it could cause your main tank to explode – although this is unlikely. However, even if the tank doesn’t explode, if the expanded water ... Watts 374A Bronze Pressure Regulator for Hot Water Hydronic Baseboard Heater Accessories. This water pressure safety relief valve is used for hot water heating and supply boilers. It provides pressure protection only. The rugged bronze body construction resists corrosive conditions of water supplies. The standard pressure relief setting is 30 …Cost. Pressure tanks are bigger and more expensive than expansion bladder tanks, although price varies for both tanks depending on their capacity and quality. Expect to spend between $50 and $700 on a pressure tank for residential use. The cost of a commercial pressure tank is even more expensive: up to $1,500. Steel-Type Expansion Tank maintenance should include: Test the level in the tank to ensure it is not waterlogged or overfilled. Additionally, this can cause problems with the loop and cause the pressure relief valve to vent unnecessarily. Check the tank for rust and corrosion. Lastly, ensure tanks are properly mounted and installed at the ... Corrosion resistant 18 gauge galavanized steel provides safe and secure installation. Supports large 5 gallon or small 2 gallon expansion tanks. The durable support base bears the weight of the expansion tank. Inclued nylon straps keep tank securely in place. Bracket slots allow use with any water heater seismic safety straps up to 1-3/4" wide.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. The incoming water pressure is gauge checked at 60 psi and the temperature is 120 degrees checked …Hot water from a tap or shower head has become a main staple of the modern home. The ability to turn on the hot water tap and almost instantly obtain hot water is a feature of most...5-Gallon Hydronic Expansion Tank. Model PMET 5. Capacity (Gallons) Interior powder coating is permanently bonded to the tank shell for ultimate protection on the water side of the water heater expansion tank. Heavy duty butyl rubber diaphragm ensures long life. Maximum working pressure 100 PSI.So the only mistake I made was you guys are forced to put them in on the cold water inlet of your tanks. We put them on the hot water outlet. Same effect. ... Since there is not be a shut off valve installed between the expansion tank the the water heater, we normaly do plumb a Tee in at the top of the water heater and install the expansion ...1. Leaking expansion tank. 2. Tank pressure loss. 3. Tank pressure too high. 4. Air blockage. 5. Condensation on outside of tank. 6. Tank needs recharging. 7. …Signs of Trouble with a Heating Boiler Expansion Tank. Expansion tanks on hot water heating systems can be divided roughly into two groups: Older type bladderless heating system expansion tanks (atmospheric expansion tanks) and; Newer type internal bladder-type expansion tanks such as those sold by Amtrol Inc.; The behavior, maintenance, …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 …Disconnect the expansion tank completely. from the heating system and then measure air pressure using an accurate air pressure gauge at the tank's air valve. Cool down and drain the hot water heating system until its pressure reading is at zero psi. and then measure air pressure using an accurate air pressure gauge at the tank's air valve.Sep 25, 2023 · Water Heater Expansion Tank Cost Breakdown. The main factors that influence the cost of installing a hot water heater expansion tank are materials—including the size and type of tank you install—and labor. Size. Most smaller homes will need a 2-gallon expansion tank, which costs $40 to $60. AMTROL ST-12 (Therm-X-Trol) is a water heater expansion tank, designed for use in domestic hot water heating systems to eliminate the potential hazards of water expansion. Water heater expansion tank is commonly installed in a domestic hot water system that contains a backflow preventer, a check valve or a pressure reducing valve. AMTROL ST …Apr 11, 2014 · Expansion Tanks on the How-It-Works series.Expansion tanks are critical components to your Plumbing and Hydronic Heating systems because they prevent your pu... The design is simple: create a true flow-through configuration. Wessels manufactures expansion tank products built in accordance with the ASME boiler and pressure vessel code. Wessels Full-Flow Bladder Tanks feature: Butyl bladder material –does not support nutrients found on natural rubber. Water circulation through the tank –every cycle ...Expansion tank installation on a water heater? When do you need a thermal expansion tank? In this video, I am explaining what an expansion tank is, what does...Jan 16, 2007 · List Price: $78.40. Metal. Made in USA. Accepts expanded water caused by thermal expansion. Returns water to the system when hot water is used. Prevents the relief valve from going off. Inline thermal expansion tank. Accepts expanded water caused by thermal expansion. Show more. Hot water tank piping diagrams are essential for designing and installing an efficient and reliable hot water system in any residential or commercial building. The heart of any hot... An expansion tank is a small two-gallon vessel with a rubber bladder inside. A portion of the vessel is filled with air, which compresses when force is applied to it. Water cannot compress. As soon as the air compresses it takes the load applied by thermal increase and relieves the water pressure from the rest of the plumbing. 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 …A tank can be viewed as a container of air and water. The goal in sizing a tank is to make sure the air side is large enough so that when the desired amount of water is put in the tank, the air is not compressed to a pressure greater than system design. Select a PDF help sheet from our list of tanks below for assistance in sizing your pressure ...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.Water Heater Expansion Tank Cost Breakdown. The main factors that influence the cost of installing a hot water heater expansion tank are materials—including the size and type of tank you install—and labor. Size. Most smaller homes will need a 2-gallon expansion tank, which costs $40 to $60.Plumbing & Hot Water; Heating Systems; Commercial Products. Hydronic Heating & Chilled Water; Plumbing & Domestic Hot Water; Fire Protection; Pump Systems; Experience Amtrol. ... Hydronic Expansion Tank Sizing. Residential Commercial: Boiler Net Output: BTU/hour: Type of Radiation: Recommended Model: WELL TANK SIZING . THERMAL …2. Water expanding into the pressure tank due to thermal expansion will register as flow (phantom flow). I do that. Small amount of extra flow is recorded by the softener, if your calculations are that critical. To avoid #1 and #2 totally, add a check valve at the output of the softener, and add a thermal expansion tank.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 …To maintain a constant pressure, an expansion vessel is installed to contain the increase in the water volume as it expands as it heats up. The expansion vessel is divided into two compartments separated by a diaphragm. There is water on one side and air on the other side. Initially the air pressure equals the system pressure. 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 ... A water heater expansion tank is a small tank installed on the cold water supply line to a water heater. Its purpose is to help protect the . When water is heated, it expands, and the volume increases. In a closed plumbing system, the expanding water has nowhere to go and can cause pressure to build up, potentially leading to leaks or … 0 / 0. AMTROL ST-12 (Therm-X-Trol) is a water heater expansion tank, designed for use in domestic hot water heating systems to eliminate the potential hazards of water expansion. Water heater expansion tank is commonly installed in a domestic hot water system that contains a backflow preventer, a check valve or a pressure reducing valve. Hot water heater expansion tanks can help protect your hot water heater and prevent it from exploding, as well as regulate your water pressure. See the price range for a water heater expansion tank: …And when heated, it expands in volume: the contents of a 40 gallon water tank can expand by half a gallon or more when heated! Neither of these properties bode ... VEVOR Electric Mini-Tank Water Heater, 2.5-Gallon Tank Hot Water Boiler Storage, 1400W Power, Safety Temperature Pressure Valve Easy Install, for Kichen Bathroom Restaurant, Shelf Wall Floor Mounted 3.2 out of 5 stars 9 Oct 20, 2017 ... We install them on all our water heaters now (and mixing valves). The expansion tank does as its name suggests. It allows for expansion in the ...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.Designed to accommodate the natural thermal expansion of water in a water heating system. A.O. Smith Expansion Tanks are light weight, easy to install and afford years of reliable service. ★★★★★ ★★★★★. 4.5. (8 reviews) Model: LET …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.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.Jan 19, 2023 · How to Safely Remove an Old Water Heater: A Step-by-Step Guide. Jan 29, 2024. Removing an old water heater might seem daunting, but with the right approach, it can be done safely and efficiently. In this guide, we'll walk you through the process step-by-step, as explained by Steve from Fast Water Heater Company. Step 1: Drain the Water Heater... 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 over tighten the connector as this can damage it. Overview. Expansion tank for heater overflow works on heaters up to 50 gallon. Powder coated interior shell protects against corrosion, assures long trouble free life. Exterior powder coat paint for long life and anti-corrosion, certified to automotive ASTM standards. Proper tank sizing is critical to the performance of your water heater.The size needed for your expansion tank is determined by the size of your home's water heater. Expansion tanks are available in 2-gallon and 4.5-gallon sizes. A 2-gallon tank will be appropriate for water heaters up to 50 gallons. An adequately sized tank should have a volume that equals 2% to 5% of the water volume within the system.Maine follows the international plumbing code when it comes to water heater expansion tanks. Maryland. Maryland follows the international plumbing code for water heater expansion tanks. Massachusetts. In Massachusetts, all hot water boilers are required to have expansion tanks. You can find the full code here.Installing an expansion tank is well worth your time and money for the peace of mind it provides. Step 1: Make a Plan. At this point, you will have a plan as to how you are going to run a branch line off of your hot water tank cold water supply to the expansion tank. Sketch out a diagram and obtain the correct fittings.A vertical 120-gallon propane tank is 55 inches tall and 30 inches in diameter, whereas a horizontal tank of the same capacity is 24 inches in diameter and 66 inches long. A 120-ga...Hot water heating system expansion tank / compression tank installation, troubleshooting, repair questions & answers. This article series explains how to identify, inspect, install, repair, or service heating boiler expansion tanks: here we explain the function of expansion tanks on hot water (hydronic) heating systems.Jun 9, 2020 · Highlights. 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. 2. Water expanding into the pressure tank due to thermal expansion will register as flow (phantom flow). I do that. Small amount of extra flow is recorded by the softener, if your calculations are that critical. To avoid #1 and #2 totally, add a check valve at the output of the softener, and add a thermal expansion tank.
Expansion Vessels. Expansion tanks are also known as expansion vessels and are used to protect closed water heating systems and domestic hot water systems from excessive pressure. As the water heats up the pressure can increase by 4.5% so they are a very important part of any sealed system. A choice of capacities from top trade brands …. Maple crown royal
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.After Canada, now Australia has found that controversial facial recognition company, Clearview AI, broke national privacy laws when it covertly collected citizens’ facial biometric...The One That Started It All™ Extrol expansion tanks accept expanded fluid in closed-loop hydronic systems to control pressure buildup, improve comfort and help reduce energy costs. Nearly seven decades after inventing the first diaphragm expansion tank, Amtrol’s lineup now includes specialty models engineered for modern, high-efficiency systems. …When water is heated, it expands due to a phenomenon known as thermal expansion. Expansion tanks are designed to safely absorb the excess water created and prevent relief valves from triggering. We offer a range of expansion tanks for … The thermal expansion tanks are engineered to meet ASME standards, and are also available in non-code designs. Wessels thermal expansion tanks are offered in industry’s broadest range from 2 to 4,000 gallons and up to 250 PSI. Pressurized thermal expansion tanks differ from plain steel expansion tanks in that a flexible bladder or diaphragm ... 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 over tighten the connector as this can damage it.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 …Factory pre-charged at 40 psi. Certified with cUPC and NSF 61 compliant. Brass air charging port with O-ring seal. 16-Gauge cold rolled steel shell. High quality coating prevents corrosion. 100% butyl rubber diaphragm lined with polypropylene. Maximum pressure of 150 psi. Maximum temperature rating of 200 degree F.Expansion tanks are required in heating, cooling or air condition system to avoid unacceptable increases of system pressures when water expands during heat-up. …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 …Heating boiler expansion tank / compression tank air adjustment valve & air vent valve troubleshooting guide: This article explains the difference between the air pressure adjustment valve on an internal-bladder compression/expansion tank and the a automatic air vent valve found on both bladder type and bladderless type expansion tanks on hot …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 ...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 feed and expansion tank, header tank, or feed and expansion cistern as it is technically known, is a cistern which supplies the central heating circuit with water and accommodates the expansion of the water when it is heated by the boiler.It is typically made out of plastic. However, like cold water storage cisterns, other materials have …Dec 1, 2016 ... The expansion tank is installed on the water supply pipe that supplies the water heater. Water expands as it is heated, and without the room to ...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...Learn what a water heater expansion tank is, how it works, and why you may need one for your closed plumbing system. Find …Expansion Vessels. Expansion tanks are also known as expansion vessels and are used to protect closed water heating systems and domestic hot water systems from excessive pressure. As the water heats up the pressure can increase by 4.5% so they are a very important part of any sealed system. A choice of capacities from top trade brands …Apr 11, 2018 · Hydronic Hot Water Systems. This calculator covers the design and selection of a hydronic hot water expansion tank. The expansion tank is a part of an overall hot water system that often includes a hot water generator (fuel fired boiler), piping, valves/fittings, water treatment, hot water coils (air handling units and fan coil units) and hot water pump(s). Thermal expansion relief valves and expansion tanks offer an outlet for steam and air when hot water heats up. While they perform the same function, they do it differently. If your plumbing system is a closed-loop system, you must have either a thermal expansion relief valve or an expansion tank above your water heater..