A. O. Smith Water Heaters at Lowes (2024)

Water pressure gauge with a lazy hand

Pressure reducing valve

Thermal expansion tank

High water pressure is one of the main reasons water heaters leak prematurely.

Plumbing codes require that your home's water pressure be 80 pounds per square inch (psi) or less. Most experts recommend 50-60 psi.

If your old water heater leaked prematurely, check your home's water pressure with a pressure gauge (available at hardware stores and home centers for a few dollars). Measure the water pressure over a 24-hour period. (Water pressures are highest at night.)

Controlling high water pressure helps protect your water heater, toilet valves, washing machine hoses, and the electronic valves on washing machines, dishwashers, ice makers and other appliances.

Plumbing codes require that your home's water pressure be no higher than 80 psi. If your water pressure exceeds 80 psi, install a Pressure Reducing Valve.

Pressure Reducing Valves are usually set at the factory to 50 psi. However, they are adjustable. Most experts recommend setting the Pressure Reducing Valve to 50 psi.

Controlling high water pressure helps protect your water heater, toilet valves, washing machine hoses, and the electronic valves on washing machines, dishwashers, ice makers and other appliances.

Water meters and Pressure Reducing Valves usually have built-in check valves that create a "closed" plumbing system.

Closed plumbing systems require a Thermal Expansion Tank.

A dripping T&P Relief Valve is a strong indicator that your plumbing system is "closed" and you need a Thermal Expansion Tank.

After installing a Pressure Reducing Valve, leave the water pressure gauge in place for a second test.

Heating water can increase the home's water pressure dramatically. But you can use a water pressure gauge to tell if you need a Thermal Expansion Tank.

Measure your home's water pressure.

Run the hot water from a faucet for 2-3 minutes to force the water heater into operation.

Monitor the water pressure while the water heater is in a heating cycle.

If the water pressure increases when the water heater is heating, your plumbing system is "closed" and your home needs a Thermal Expansion Tank.

If you already have a Thermal Expansion Tank, this test will determine if the expansion tank is working properly.

If you have an expansion tank and the pressure increases when the water heater is heating water, the expansion tank's rubber bladder may have failed, the tank may have the wrong air pressure, or it may be too small for your home.

See Thermal Expansion Tanks for more information.

High water pressure and thermal expansion are a leading cause of premature water heater leaks, but the corrosive effects of water also plays a role.

How corrosive your water is depends on where your water utility gets its water and how your water is treated.

Water softeners greatly increase the corrosive effects of water.

Water heaters come equipped with an anode rod which helps reduce tank corrosion.

Anode rods help reduce tank corrosion but are consumed in the process.

Anode rods are typically made from magnesium, aluminum or zinc alloys.

(Top) This is what a new anode rod looks like.

(Middle) This is a partially depleted anode rod.

(Bottom) This anode rod is completely depleted. Only the structural wire remains.

Checking and replacing the anode rod from time to time can help prevent premature tank leaks and can extend the life of your water heater.

Have your plumber check your water heater's anode rod after the first six months of operation to determine the depletion rate. Most experts advise annual check ups after that.

Water conditions in your area greatly affect the anode rod's life. Water softeners reduce the life of anode rods. If your home has a water softener, the anode rod should be checked and replaced more often.

Have your plumber replace your water heater's anode rod if it's depleted.