Amongst the new types of h2o heaters bachelor today, the conventional tank-type unit of measurement is still the most popular. Of these hot water storage units, approximately half of them are gas-fired and the other one-half are electric. Any plumber will tell you that electric water heaters are the easiest to install, only not anybody knows how to fix one when it breaks downwards.
In America, nosotros will replace about 1.5 million water heaters each year simply because they are not performing as expected. How many of these units could exist repaired, thereby extending their useful life? In this article, we will identify the main components of an electric h2o heater, explain how they work together to provide hot water for a domicile, and describe what can be done to become improve performance utilizing an electric water heater thermostat.
Water Heater Elements
The device that converts electricity into heat inside of a water heater is the chemical element. It’s basically an electric resistor. When electricity flows through the element, it gets extremely hot. Since the element is immersed in the water, it transfers the heat to the water until it reaches a specific temperature (typically 120 degrees).
Elements come in dissimilar shapes to amend their performance and longevity and are sized co-ordinate to wattage. The most mutual size is 4500 watts, with 3500 and 5500 watt versions also available. These sizes are not interchangeable, only are specified on the rating plate of every water heater.
Electrical Water Heater Thermostats
The upper thermostat is the principal command component for about water heaters. It controls both the upper and lower elements. A thermostat is essentially a temperature-activated switch. When the thermostat senses a water temperature below its set up point, information technology will energize one of the elements in response to this “phone call for rut.”
The way the thermostat senses the h2o temperature is unique since information technology never comes in straight contact with the water. The dorsum of the thermostat senses the temperature of the outer layer of the tank. It’s pressed tightly against it and is held in identify past a clip. This metallic-to-metal contact transfers estrus from the water to the thermostat by conduction through the shell of the tank. All other parts of the tank are covered with insulation except for the two spots where the thermostats are mounted.
Most electric water heaters to a higher place xx gallons have two thermostats that sense the temperature of the water in both the top and lesser of the tank. The upper thermostat is the boss and ever tells the lower thermostat what to do.
Sequence of Operation
When you lot wake up in the morn and brainstorm to apply hot water, you effectively draw water off the top of the tank. As the hot water is dispensed, the heater simultaneously fills with cold water. Since that water is directed to the bottom of the tank through the dip tube, the lower thermostat senses a drop in temperature outset.
It calls out to the upper electric h2o heater thermostat, and equally long every bit the upper half of the tank is still hot, it will energize the lower element. In most residential units, the elements are only energized one at a time. If you merely use a few gallons of hot water, the lower thermostat lone can handle the chore. Even so, if you have a hard fourth dimension waking up and need a long shower, or if there is a line outside the bathroom door, you may end upwardly emptying the tank of all its bachelor hot water.
This could happen, but non if the upper element has anything to say about it. When the water in the superlative half of the tank begins to cool off, the upper thermostat will take over to maintain the temperature of the exiting water before it disappoints the next bather.
A storage-type water heater carries what is chosen a “starting time-hour rating.” This rating is typically near 30% greater than the storage chapters of the tank. Since the elements become energized, as soon as they sense a drop in temperature, the heater begins making more hot water. In the bridge of 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 includes a few safe devices to go along you lot from getting scalded by hot water, electrocuted or injured by an exploding tank. These pressure level vessels are not to be trifled with, but most plumbers accept fretfulness made of hard drawn copper, so they are not hands intimidated.
The upper electric water heater thermostat includes a high-temperature limit device that will disconnect ability to both elements if it senses a temperature above 150 degrees. Water at this temperature will burn your peel in a hot second.
Water heaters, like all electrical appliances, have an equipment ground lug inside the wiring compartment at the top of the tank. This footing lug provides a low resistance path for electric current to flow in example the jacket of the heater becomes energized.
The relief valve is arguably the near important safety device in any pressurized heating organisation. If the thermostat fails and the high-temperature limit doesn’t shut downwardly the heater, the force per unit area relief valve will prevent the unit of measurement from causing whatever existent harm. If it senses a pressure above 150 psi or a temperature above 210 degrees, just below the boiling point of h2o, it volition open, allowing that pressure to exist relieved in a controlled, rather than explosive manner.
All these safety devices should be checked periodically equally part of routine maintenance to continue the heater running safely and trouble-free.
Improving Your Heater’s Performance
The biggest thief robbing a h2o heater of efficiency is sediment. Sediment is formed out of minerals like calcium and magnesium that are constitute in difficult water. These undissolved minerals, along with whatsoever sand that might exist suspended in the h2o, collect on the lesser of every tank-blazon water heater, reducing its capacity to store hot h2o.
This crusty layer of elements affects gas-fired and electric heaters in different ways. In the electrical units, the sediment builds up until it buries the bottom element. Information technology displaces the cool water that normally surrounds the element causing information technology to overheat.
A homeowner may not fifty-fifty notice that the element has failed, only that the h2o heater just doesn’t seem to keep upwardly anymore.
Regular Maintenance of a Water Heater
Diagnosing and replacing a failed bottom element is a very common repair, merely to preclude information technology from happening again, the sediment, or as much of information technology as possible, should exist flushed out. Periodic flushing of sediment could have prevented the repair birthday and will go along the heater operating at its maximum capacity.
1 recommendation a plumber might brand would be to install a sediment filter if sand is present at the bottom of the unit. If minerals seem to exist building up chop-chop, installing a h2o softener would also be a great idea. These measures will capture the sediment and remove the minerals from the water before the tank always sees them.
Another common problem, that could be mistaken for a tank leak, is a dripping relief valve. While at that place is more than i cause for this, it’due south commonly an issue with the valve itself. About one-half of the time, all one has to practice is practise the relief valve to stop the drip. If that doesn’t piece of work, and you verify there is no overpressure or high-temperature condition, you simply supercede the valve.
Repair Before Replacing
A piddling preventative maintenance goes a long fashion toward extending an electric h2o heater’s lifespan and repairs can yield college margins for plumbers doing the piece of work. Additionally, massive quantities of non-recyclable waste in scrapyards and landfills can be avoided. To larn more than about how a water heater functions and how to troubleshoot and repair it, go to SkillMill’s Electric H2o Heater Functioning course.
Interplay Learning Plumbing & HVAC Expert
Frank is Interplay’s resident plumbing and HVAC skilful. While he began his career in the plumbing merchandise, his passion for HVAC led him to get an Associate Professor and HVAC Programme Chair, at Ivy Tech Community College. Frank is a Licensed Mechanical, Plumbing and Electric Contractor, and owns his own mechanical services visitor. As an educator, Frank is a firm believer in instruction the fundamentals and has a gift for simplifying circuitous concepts.