How a Water Heater Works
If you are hoping to better understand how a water
heater works in order to fix it in the future or if you
are simply curious this article will go through the
basics. While there are a number of different designs
of water heaters the most used the iconic cylinder
shape that you will find the basement or garage of
your house. The system used in these cylinders is
actually very simple.
1. Incoming Water Water is fed into your house through plumbing. The
water can come from your own well or the town
watershed. Either way it flows through the pipes, passing the shut-off valve and enters the water heater
where it sits. The heater is constantly full of water waiting to be used.
2. Heating the Water The cold or cool water will enter your water heater through the dip tube through the top of the tank and
travel down to the bottom. At the bottom of the tank the water will come into contact with the heating
mechanism. Electric water heaters will have heating elements inside of the tank (usually in the form of
wired coils around the pipes) while gas water heaters will have a burner and chimney system (the
burner is placed directly below the cold water at the bottom of the tank).
On the outside of a tank there is a thermostat which is set to the desired temperature (recommended
tempertatures are between (120-180 degrees Farenheit).
The thermostat is usually located below a protective cover
plate and has a knob you can turn to set the temperature.
The thermostat also measures the current heat of the
water. The heating mechanism will stay on until the water
reaches the set level. The pipe entering and existing the
water heater is an elongated U-shape. As the water heats
up it will naturally raise to the top of the tank above the
colder, denser water. This principle of heat rising is the
base principle of how the heater works and it is how the cold
water and hot water are separated. As the water heats up it
continues up the water heater eventually reaching the heat-
out pipe on top of the tank (these pipes should be marked so
you dont accidentally burn yourself). The water leaving the
water heater through this pipe is the hottest the water in
the tank will ever be.
3. To Your Shower The hot water will sit on top of the water heater until you wish to use it. The water in the heater is also
pressurized so when you release the spout upstairs in the house the water pressure will push the hot
water up and out of your showerhead. If you are constantly requiring hot water you will find that the
water heater will not be able to heat up the cold water fast enough to keep up with demand (you might
need a larger heater). The water heater design is very simple and rests on the principle of hot water
rising above cold, dense water. If you are interested in creating a self-sustaining water flow in your
house look into groundwater mapping and installing your own well. Good luck in your future repairs.
Photo Credit: Christopher, smynsbrg