The Function of an Electric Water Heater Thermostat

The Function of an Electric Water Heater Thermostat

No one is fond of a cold shower. Even worse is receiving overcooked when you run the hot water. Correctly setting the temperature on your water heater is significant not only for your health and safety but also for saving money on your electricity bill.

Among the new categories of water heaters obtainable today. The conventional tank-type unit is still the most popular of these hot water storage units. Approximately half of them are gas-fired and the other half is electric. Any plumber will tell you that electric water heaters are the coolest to install but not everyone knows how to fix one when it breaks down.

In America, we will substitute about 1.5 million water heaters each year simply because they are not carrying out as expected. How many of these units could be mended, thereby spreading their useful life? In this article, we will classify the main components of an electric water heater, explain how they work together to provide hot water for the home, and describe what can be done to get better performance applying an electric water heater thermostat.

Water Heater Elements

The device that renovates electricity into heat inside of a water heater is the element. It’s essentially an electrical resistor. When electricity flows through the element, it gets tremendously hot. Since the element is absorbed in the water. it handovers the heat to the water until it spreads to a specific temperature (typically 120 degrees).

Elements come in different shapes to advance their performance and permanency and are sized according to wattage. The most common size is 4500 watts, with 3500 and 5500-watt versions also available. These sizes are not substitutable but are quantified on the rating plate of every water heater.

Electric Water Heater Thermostats

Electric Water Heater Thermostats

The upper thermostat is the main control constituent for most water heaters. It controls both the upper and lower elements. A thermostat is fundamentally a temperature-activated switch. When the thermostat senses a water temperature below its set point it will strengthen one of the elements in answer to this “call for heat.”

The way the thermostat sanities the water temperature is exclusive since it never comes in direct contact with the water. The back of the thermostat senses the temperature of the outer layer of the tank. It’s pressed strongly against it and is held in place by a clip. This metal-to-metal contact transfers heat from the water to the thermostat by transmission through the shell of the tank. All other parts of the tank are enclosed with lagging except for the two spots where the thermostats are straddling.

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.

Sequence of Operation

When you wake up in the morning and begin to use hot water. You efficiently draw water off the top of the tank. As the hot water is distributed the heater instantaneously fills with cold water. Since that water is absorbed to the bottom of the tank through the dip tube the lower thermostat senses a drop in temperature first.

It calls out to the upper electric water heater thermostat and as long as the upper half of the tank is still hot. It will strengthen the lower element. In most housing units the elements are only energized one at a time. If you only use a few gallons of hot water the lower thermostat alone can handle the job. However, if you have a hard time waking up and need a long shower, or if there is a line outside the bathroom door, you may end up emptying the tank of all its obtainable hot water.

This could happen, but not if the upper element has anything to say about it. When the water in the top half of the tank begins to cool off, the upper thermostat will take over to preserve the temperature of the departing water before it dissatisfies the next bather.

A storage-type water heater transmits what is called a “first-hour rating.” This rating is typically about 30% greater than the storage volume of the tank. Since the elements become animated, as soon as they sense a drop in temperature. The heater begins making more hot water. In an hour, you can get more than 50 gallons of hot water out of a nominal 40-gallon tank.

Limit Controls, Grounding, and Pressure Relief

Every water heater comprises a few security devices to keep you from getting overcooked by hot water, electrocuted, or injured by an explosion tank. These pressure vessels are not to be flirted with, but most plumbers have nerves made of hard-drawn copper, so they are not easily intimidated.

The upper electric water heater thermostat comprises a high-temperature limit device that will separate power to both elements if it senses a temperature above 150 degrees. Water at this temperature will burn your skin in a hot second.

Water heaters, like all electrical applications, have an apparatus ground lug inside the wiring section at the top of the tank. This ground lug provides a low confrontation path for current to flow in case the jacket of the heater becomes energized.

The release valve is debatably the most significant safety device in any hassled heating system. If the thermostat fails and the high-temperature limit doesn’t shut down the heater, the pressure release valve will prevent the unit from causing any real damage. If it senses a pressure above 150 psi or a temperature above 210 degrees, just below the boiling point of water, it will open, allowing that pressure to be relieved in a controlled, rather than explosive manner.

All these safety devices should be checked occasionally as part of routine upkeep to keep the heater running safely and trouble-free.

Improving Your Heater's Performance

The biggest thief raiding a water heater of competence is dregs. Sediment is formed out of minerals like calcium and magnesium that are found in hard water. These undissolved minerals, along with any sand that might be suspended in the water, collect on the bottom of every tank-type water heater, reducing its capability to stock hot water.

This crispy layer of elements affects gas-fired and electric heaters in different ways. In the electric units, the dregs build up until it buries the bottom element. It displaces the cool water that normally environs the element causing it to overheat.

A homeowner may not even notice that the element is unsuccessful, only that the water heater just doesn’t seem to keep up anymore.

Repair Before Replacing

A little preemptive maintenance goes a long way toward spreading an electric water heater’s lifespan and repairs can yield higher limits for plumbers doing the work. Moreover, enormous quantities of non-recyclable waste in scrapyards and landfills can be evaded. To learn more about how a water heater functions and how to troubleshoot and repair it, go to my HVAC.com.




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