Electric water heaters are a bit more complicated than their gas brethren. Troubleshooting electric water heater problems is a process of elimination, but the first step you always must take is focusing on safety.
Obviously, the issue here is electricity. An electric water heater is often wired for more volts than the average household item. You will typically find 240 volts being used, which is a serious amount of electricity. If you run afoul of this type of electrical flow, you can electrocute yourself with grave results. It is absolutely vital that you turn off all electricity flowing to the water heater before you even think about poking around in it. This is typically done by tripping the circuit breakers at the fuse box.
Never proceed with the repair of an electrical device if you have not first turned off the power
Once you turn off the electricity, your next step is to hurry up and wait. The water in the tank is hot and needs to cool down. At a minimum, the temperature will be 120 degrees, which is more than enough to burn your skin. Give the tank a bit of time and consider removing the anode rod at the top, to allow some heat to escape. Only then are you ready to troubleshoot your hot water problem.
Electric Hot Water Heater Problems – No Hot Water
If you get only cold water when you turn on the hot water faucets in your home, you most likely have a thermostat or electrical flow problem. The first thing to do is to check your circuit breakers. There are typically two that control an electric water heater. If one or both are tripped, your home may have simply experienced a random power surge that was a one-time event. Reset the circuit breakers and give the heater an hour or so to raise the temperature of the water in the tank.
If the circuit breakers are not tripped, the thermostat is the next place to look. The thermostat is the “brain” of the operation, in that it controls when the heating elements are turned on and for how long. Again, we want to make sure the electricity is OFF before looking at the device because we are going to be testing electrical components. Check the power to confirm it is off and then check it again.
Depending on the design of your heater, you may have one or two thermostats. All need to be tested. To do this, unscrew and remove the panels covering the devices. They usually look like metal patches. Once they’re removed, you should see a thermostat above the socket for the heating element. Electricity is sent into the top of the thermostat and travels down through a number of switches. Wires at the bottom of the thermostat then connect to a heating element. You will only see the socket for the heating element, because the end that actually heats up is positioned within the water tank.
The area where thermostats often fail is at the reset switch. That button is rarely used, so it can corrode and impact the flow of electricity to the heating element. You can test if this has happened by using a device known as a multimeter.
A multimeter tests whether an electrical current can pass from one point to another. The device has two wired leads. By placing one lead at each end of the area to be tested, the meter can tell if an electrical pulse can travel between the two locations. Make sure you are using the “ohm” or “resistance” setting on your multimeter.
To test if there is a problem with the reset switch, place one lead of your multimeter on the top screw on the left side of the thermostat. Place the second lead on the screw below the reset switch, on the same side. If the multimeter shows electrical activity, the reset switch is fine. Test the right side of the thermostat in the same way to make sure there isn’t a problem on that side.
If everything still tests properly, you next need to test the thermostat itself. First, turn the temperature setting all the way up. Then put one multimeter lead on the middle screw on the thermostat and connect the second multimeter lead to the bottom screw on the same side. Repeat for the other side of the thermostat. If electrical activity is shown on both sides, the thermostat is fine. If not, it needs to be replaced. That will usually cost less than $50.
The final test is to determine whether the thermostat is communicating correctly with the heating element. The heating element is located just below the thermostat. Remove the wires which run from the thermostat to the back of the heating element. Now connect the multimeter between the screws which were securing those wires. Look for a reading between 5 and 55 ohms. If you get this reading, the thermostat is not the problem – and you may have failed heating elements due to an electrical spike, corrosion or some other issue. New heating elements should cost less than $25.
Having difficulties picturing how to conduct these tests?
This video shows how it is done.Watch Here
Not Enough Hot Water
The vast majority of problems with modern electric water heaters are caused when heating elements fail. Modern water heaters usually have two heating elements, which perform different duties.
The first heating element is located at the top of the tank. Its purpose is to provide extra power to heat water quickly. This extra power is typically needed when there is a lot of hot water being used at one time. This element would come on, for example, when two or three people in a row take showers in the morning.
The second heating element is found in the bottom of the tank. It is usually located on the same side of the heater as the top element. The bottom one carries most of the burden in heating the water in the tank. When hot water is pulled from the tank, cold water is introduced into the bottom to keep the tank filled. This cold water needs to be heated, and the lower heating element is responsible for doing that.
A good way to troubleshoot is to run your shower for a little while, and note the exact problem with the hot water. Is the water simply not hot enough – or is there not enough of it? These two common problems have different causes.
If your shower water starts out hot, then becomes lukewarm and slowly changes to cold, you should focus on the upper heating element when troubleshooting the problem. The lukewarm water is typically indicative of an upper heating element that is not turning on to supply the required “extra” heat. A failed upper element will cause the average temperature of the water in the tank to drop to 80 degrees or so, since the lower element is unable to heat the incoming cold water quickly enough to meet the demand.
On the other hand, if you get an initial burst of hot water followed by completely cold water, the problem is most likely the bottom heating element. The hot water you get at first is produced because the upper element is working, but that element is not enough to heat the water in the lower half of the tank. That’s why the initial burst of hot water is quickly followed by all cold water.
Prefer a more technical approach? You can use your multimeter to test whether the heating elements are conducting the electricity required to heat the water. Connect your leads to each side of the socket protruding below the thermostat and see if you get a reading. If not, you have a bad element.
Is it worth going through the process of replacing a heating element? It certainly makes sense financially. A new heater will run you more $1,000 with installation. A new heating element will usually cost between $15 and $25. Many people often just replace both of them when there’s a problem, just to make sure the heater remains in good shape.
Suffer from scalding water? The news is good. Troubleshooting this hot water problem is a breeze and solving it probably won’t cost a thing. The problem is usually that the temperature gauge on the heater is turned too high. Locate the gauge just below the thermostat and turn it down to 120 degrees. This should get rid of the problem and will save you a good bit of money on your utility bill as well.
There are occasionally cases when scalding water is caused by a defective thermostat. If you turn down the temperature on the thermostat and there is no change, run the same tests as detailed in the “no hot water” section in this article, to determine if you have a thermostat issue. This is rarely the case, but it is a possible cause for water that’s too hot.
A new water heater is expensive. Troubleshooting electric hot water heater problems is fairly easy, as are the necessary repairs. Give it a try!