Do I need an expansion tank on my hot water heater?

When is it required? 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.

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Keeping this in consideration, what is the purpose of an expansion tank on a 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.

One may also ask, is an 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.

is an expansion tank required for a water heater in California?

California Plumbing Code Section 608.3 requires an expansion tank to be installed on the water heater when it is a closed system. There are some Water Districts that may not install a check valve or backflow prevention device in every situation.

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.

Related Question Answers

What size expansion tank do I need for a 40 gallon water heater?

Sizing Charts

Static Supply Pressure (psi)	Water Heater Size (Gallons)
	40	80
40	ST-5	ST-8
60	ST-5	ST-8
80	ST-5	ST-12

Can hot water heaters be laid down?

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.

How long does an expansion tank last?

10 years

What happens when an expansion tank fails?

If the expansion tank is missing or not operating properly, pressure in the system may cause the boiler's pressure relief valve to vent water. Or, air bubbles being released by the heating water may gather somewhere else in the system, causing a blockage that stops the flow of hot water.

How do I know if my expansion tank is bad?

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.

Do hot water heaters need an expansion tank?

Why you need an expansion tank with a closed loop system An expansion tank will prevent damage to your water heater and plumbing system. 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.

How do you install an expansion tank on a water heater?

It is recommended to install the thermal expansion tank on the cold water line, horizontally and close to the water heater. Use the threaded T- fitting, Teflon tape, and pipe wrench to make the watertight connection. Remove the trapped air by opening the hot water tap.

Why do you need an expansion tank?

Your expansion tank can help you to save your system. The expansion tank serves as a backup system to prevent overworking your plumbing. The excess water volume, instead of causing too much pressure on the plumbing, rushes into the expansion tank and lowers the pressure in the water heater to safer levels.

How do you drain the expansion tank on a water heater?

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.

What is a closed water system?

A closed water heater system means that the hot water cannot expand beyond the valves and mix with the municipal water. The valves that are usually found in the closed systems are the check valve, pressure reducing valve, mixing valve, backflow preventer and other.

Do you need an expansion tank with a pressure reducing valve?

If you have excess pressure over 80 P.S.I. supplied to your home by the city water supply, an expansion tank does nothing to correct this. That's the job of the pressure reducing valve (PRV). It protects against the constant fluctuation of high pressure caused by thermal expansion upon a closed-loop system.

How do expansion tanks work?

Expansion tanks work by equalizing pressure throughout the system. As hot water enters the heating system, the pressure in the system increases. As pressure increases, the diaphragm in the expansion tank is pushed down. This compresses the air in the tank, creating more space for excess water to enter.

Are sediment traps required in California?

According to the 2016 California Plumbing Code (CPC), sediment traps are required for all gas appliances except: illuminating appliances, ranges, clothes dryers, decorative appliances for installation in vented fireplaces, gas fireplaces, and outdoor grills.

Does Home Depot sell expansion tanks?

Expansion Tank - Water Heater Expansion Tanks - Water Heater Parts - The Home Depot.

Do you need a permit to replace a water heater in San Diego?

All original and replacement water heater installations are required to be installed in compliance with California Plumbing Code (CPC). A plumbing permit is required for the installation of a water heater.

Can a water heater expansion tank be installed 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.

Will an expansion tank increase water pressure?

The tank won't actually increase the pressure, but the extra water will help boost the volume which, in turn, helps keep the existing pressure up.

How much does it cost to replace 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. The tank is quite easy to install with a normal 3/4-inch threaded connection.

Why install an expansion tank on a water heater?

That is an expansion tank installed on the water supply pipe to the water heater. Its purpose is to deal with thermal expansion of water as it heats up in the water heater - to prevent water pressure from getting too high. Like most substances, water expands as it is heated.