inside a water heater
February 11th, 2010
Inside a Water HeaterIf you were to cut a water heater in half, you would find that it looks something like this (electric on the left, gas on the right):
A gas water heater is nearly identical to an electric water heater, except that it does not contain the two heating elements, but instead has a gas burner at the bottom, with the chimney running up through the middle of the tank.
A water heater consists of the following parts, as shown in the figure above:
A heavy inner steel tank that holds the hot water
Typically, this tank holds 40 to 60 gallons. It has to be able to hold the pressure of a residential water system, which typically runs at 50 to 100 pounds per square inch (psi). The tank is tested to handle 300 psi. The steel tank normally has a bonded glass liner to keep rust out of the water.
Insulation surrounding the tank
A dip tube to let cold water into the tank
A pipe to let hot water out of the tank
A thermostat to control the temperature of the water inside the tank (Many electric water heaters have a separate thermostat on each element.)
Heating elements to heat the water (These are the thick electric elements similar to those you see inside an electric oven.)
A drain valve that allows you to drain the tank to replace the elements or move the tank
A pressure relief valve (This is an important safety feature that keeps the tank from exploding.)
A sacrificial anode rod to help keep the steel tank from corroding
Now let’s see how these all these parts work to provide you with hot water.
A gas water heater is nearly identical to an electric water heater, except that it does not contain the two heating elements, but instead has a gas burner at the bottom, with the chimney running up through the middle of the tank.
A water heater consists of the following parts, as shown in the figure above:
A heavy inner steel tank that holds the hot water
Typically, this tank holds 40 to 60 gallons. It has to be able to hold the pressure of a residential water system, which typically runs at 50 to 100 pounds per square inch (psi). The tank is tested to handle 300 psi. The steel tank normally has a bonded glass liner to keep rust out of the water.
Insulation surrounding the tank
A dip tube to let cold water into the tank
A pipe to let hot water out of the tank
A thermostat to control the temperature of the water inside the tank (Many electric water heaters have a separate thermostat on each element.)
Heating elements to heat the water (These are the thick electric elements similar to those you see inside an electric oven.)
A drain valve that allows you to drain the tank to replace the elements or move the tank
A pressure relief valve (This is an important safety feature that keeps the tank from exploding.)
A sacrificial anode rod to help keep the steel tank from corroding
Now let’s see how these all these parts work to provide you with hot water.
tommorow we will look at heating the water heater