Asked by: Bruno Benard
home and garden indoor environmental quality

How much is an expansion tank for hot water heater?

Last Updated: 9th January, 2020

41
Water heater expansion tank prices start at around $40 and range up to nearly $200; pricing is largely dependent on the size of the tank. For most residential installations with 40- or 50-gallon water heaters, a simple 2-gallon tank is fine.

Click to see full answer.

Also know, do I need an expansion tank on my hot water heater?

An expansion tank is always highly recommended if you have a 'closed-loop system' caused by any kind of check valve or pressure regulating valve installed on your house's water supply line. A common analogy compares having high water pressure in your home to having high blood pressure.

Also Know, how does a hot water heater expansion tank work? Expansion tanks work by equalizing pressure throughout the system. An expansion tank is a small tank divided in two sections by a rubber diaphragm. One side is connected to the pipes of the heating system and contains water. The other side is dry and contains pressurized air, set at approximately 12 psi.

Moreover, what size expansion tank do I need for a 50 gallon water heater?

Sizing Charts

Static Supply Pressure (psi) Water Heater Size (Gallons)
40 50
40 ST-5 ST-5
60 ST-5 ST-5
80 ST-5 ST-8

How do you replace an expansion tank on a hot water heater?

Just follow the steps below to safely replace your water heater expansion tank.

  1. Step 1 - Identify Your Old Expansion Tank.
  2. Step 2 - Turn Everything Off.
  3. Step 3 - Drain the Water.
  4. Step 4 - Disconnect the Expansion Tank.
  5. Step 5 - Pressurize the Expansion Tank.
  6. Step 6 - Check the Pressure.
  7. Step 7 - Teflon Tape.

Related Question Answers

Zambra Lajoso

Professional

Where does an expansion tank go on a hot water heater?

Your expansion tank can be anywhere on your plumbing system and does not need to be installed in close proximity to the water heater. It is most commonly installed using a “T” at the cold inlet to the water heater. But, functionally, it can be installed anywhere on the cold inlet line.

Medea Neiman

Professional

Rasim Guhrke

Professional

Will an expansion tank increase water pressure?

The expansion tank contains air, which is highly compressible. Expanding water from the water heater can flow into the expansion tank, where the air compresses, making room for the increased volume of water. Water pressure in the system doesn't increase significantly.

Demi Haverkotte

Explainer

How do you check pressure in an expansion tank?

How to Tell If an Expansion Tank is Working
  1. Tap on the tank. It should be hollow about half way up.
  2. Check the temperature by feeling the top and bottom of the tank. The tank should be warm on the bottom and cool on the top if it is working properly.
  3. Use an air gauge to check the pressure inside the tank.
  4. Check to see if your release valve is spurting water.

Eufemia Loreti

Explainer

Is a water heater expansion tank required by code?

The 2012 International Residential Code (P2903.4.2) requires the installation of an expansion tank on a hot water tank where thermal expansion may cause an increase in pressure. The tank is only required when the water supply system incorporates a backflow prevention device, check valve or similar device.

Darlene Uiop

Explainer

How much pressure should be in a water heater expansion tank?

The recommended water pressure is between 50 and 60 PSI. Thermal Expansion Tanks contain an air bladder which is pressurized with air, and expands and contracts to absorb the expanded water from the water heater. needed. Check the air pressure in the Expansion Tank using a tire gauge.

Moazzam Wienkopp

Pundit

How do you drain an expansion tank?

How to Drain an Expansion Tank
  1. Step 1 – Shut of the Power and Water Supply. Turn off the water supply to your water heater and also shut off the power supply.
  2. Step 2 – Find the Drain Valve. Find the drain valve on the water heater, the valve is normally at the bottom of the tank.
  3. Step 3 – Connect the Hose.
  4. Step 4 – Open the Drain Valve.

Fredesvinda Falim

Pundit

How big an expansion tank do I need?

That means you'd need an expansion tank to hold an additional 13 gallons because based on the formula above, your volume has increased to 113 gallons. One more thing to keep in mind when sizing your tank: as a rule of thumb, it should typically be 1/3 full when cold and about 1/2 full when hot.

Johara Tieze

Pundit

How big of a water pressure tank do I need?

A 10 GPM pump needed a pressure tank that holds 10 or 20 gallons. A 20 GPM pump needs a tank with 20 to 40 gallons of storage. Almost 2/3s or more of a tanks volume is filled with compressed air, it takes a very large tank to hold 10 to 40 gallons of water.

Pearly Matthew

Pundit

Why use expansion tank on hot water heater?

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.

Esmeraldo Tinitana

Teacher

What happens if expansion tank fails?

What Happens if the Expansion / Compression Tank is Not Working? The loss of air cushion in the expansion / compression tank means that at each heating-on cycle the system pressure can be too high, causing the temperature/pressure relief valve to spill.

Burgess Plum

Teacher

How much is an expansion tank?

Water heater expansion tank prices start at around $40 and range up to nearly $200; pricing is largely dependent on the size of the tank. For most residential installations with 40- or 50-gallon water heaters, a simple 2-gallon tank is fine.

Magdalen Jennessen

Teacher

What does an expansion tank do?

An expansion tank or expansion vessel is a small tank used to protect closed (not open to atmospheric pressure) water heating systems and domestic hot water systems from excessive pressure.

Gelasio Kinzkofer

Teacher

How does an expansion vessel work?

An expansion vessel is a device to cope with the expansion of water in a heating or hot water system due to increases in temperature. Inside the expansion vessel there is water on one side of the diaphragm and air or an inert gas (such as nitrogen) under pressure* on the other side.

Marieke Tobulinsky

Reviewer

Can you install expansion tank upside down?

if you install it upside down, then air goes up into the tank, and cann't get out -reducing the functionality of the tank. vertical, opening up is best.

Aimane Steinlochner

Reviewer

Is expansion tank necessary?

Although many jurisdictions now require an expansion tank to be installed at the same time that a water heater is installed, an expansion tank has not always been required in the past and may still not be required in some regions.

Juncal Luchterhand

Reviewer

Why do expansion tanks fail?

That air pressure is called the “pre-charge.” But having the tank's pre-charge higher than the water pressure will prevent the expansion tank from allowing water into the tank, thereby rendering the tank pointless. It could also rupture the rubber diaphragm since it's not designed to be inflated beyond 80 psi.

Josimar O'Rourke

Supporter

Why does my expansion tank keep filling up?

Expansion Tank. If there is not enough air in the expansion tank, the buildup of pressure will force water out of the safety relief valve located above the boiler. Without enough air in the tank, the tank fills with water. The water expands as it heats up and then escapes through the safety relief valve.

Fernando Morato

Supporter

Can you lay down a new hot water heater?

In certain situations, the hot water heater may need to be laid on its side. If the hot water heater is not properly moved while in a horizontal position, the metal casing could become damaged or the glass lining could crack. You can follow a few basic steps to protect your water heater when moving it on its side.