The upper thermostat is the main control component for most water heaters. … Most electric water heaters above 20 gallons have two thermostats that sense the temperature of the water in both the top and bottom of the tank. The upper thermostat is the boss and always tells the lower thermostat what to do.
How do I know if my water heater has two thermostats?
Electric water heaters often have two thermostats — one at the top and another at the bottom of the tank. And most tankless water heaters feature a display with a temperature readout and controls for adjusting the temperature.
How many thermostats does a water heater have?
Depending on the gallon size of the tank, an electric water heater consists of one or two thermostats which regulate the temperature of the water. The thermostats work by turning the heating elements on when the water cools below a particular temperature.
Should both thermostats on an electric water heater be set the same?
The majority of electric water heaters have two thermostats: an upper and a lower, located under two control panels. To ensure your electric water heater works as efficiently as possible, you should set both of the thermostats at the same temperature.
Why do electric water heaters have two heating elements?
With two-element designs, one element heats the water at the top of the tank while the second element heats the water within the bottom of the tank. Electric heaters feature fewer parts than gas models, but a basic understanding of how two-element models function can reduce the time needed to diagnose a problem.
What is a dual element water heater?
With a dual-element water heater, there are two heat elements – one on the top and one toward the bottom of the tank. Each element has its own thermostat, and only one element runs at a time. The top element turns on first to start the warming process.
How do I know if my hot water heater thermostat is bad?
If you turn the hot water tap and cold water runs out, then the upper thermostat is damaged. But if the water is hot that becomes later becomes cold, then you have a damaged lower thermostat.
Will a hot water heater work with only one element?
Yes, a water heater can still run if the bottom element quits. … In most water heaters, the top heating element controls the thermostat and will still work even if the bottom element fails. So provided the top heating element is working, it can still produce some hot water even if the bottom heating element fails.
What temperature should electric water heater be set on?
120 degrees Fahrenheit is the safety recommendation against scalding, but 140° is the common default setting. Most experts agree that anything below 120 degrees creates a risk for bacteria to develop inside your water heater from stagnant water, such as legionella that causes Legionnaire’s disease.
What should water heater thermostats be set at?
The short answer: 120 degrees Fahrenheit. This is the preset thermostat temperature in most new water heaters, and it’s the recommended setting of the U.S. Department of Energy. At this temperature, harmful pathogens like the kind that cause Legionnaires’ disease are prevented from multiplying and may be killed.
Do electric water heaters have thermostats?
Most electric water heaters above 20 gallons have two thermostats that sense the temperature of the water in both the top and bottom of the tank. The upper thermostat is the boss and always tells the lower thermostat what to do.
How much does it cost to replace a water heater thermostat?
The average thermostat replacement cost is between $100 and $300. Most other repairs are equally affordable. There are two main types: gas and electric. A gas unit works by way of a gas flame while an electric one works using electric elements, or coils.
How does an electric water heater thermostat work?
The thermostat is a thermistor that responds to heat by producing a small electric current. The current increases when water temperature increases, and drops when temperature drops. Changes in the electric current cause gas control to turn ON and OFF. When gas control turns ON, it releases gas to burner.