In this guide well discuss in detail the problems and solutions to AO Smith electric hot water heater repair. AO Smith Electric water heaters sometime leak from various places and cause a short, sometimes the AO Smith electric water heater wont get hot enough and the hot water runs out quickly.
Sometimes, you will find your electric water heater doesnt heat at all!*WARNING!*AO Smith electric water heaters as discussed in this repair guide utilize 240 volts of power and draw 18 amps!!! This is plenty to cause serious electrical shock or death from electrocution! Always disconnect the power to your water heater when handling any wires, or working on the water heater. AO Smith electric water heater troubleshooting requires the testing of the electrical components, and if you are afraid of handling electrical like many people, I would suggest calling a professional. Electrical testing is a dangerous job!*
No Hot Water troubleshooting a AO Smith electric water heater
The most common problem you will encounter with a AO Smith electric water heater having no hot water, or very little hot water. The first thing to check is the circuit breaker or fuse in your electrical service panel. Make sure the fuse is not tripped, or the fuse blown. Also if you have an electrical switch or power disconnect servicing your AO Smith water heater, make sure that it is in the on position. If the electrical seems to be all in the normal on positions, then it is time to check the AO Smith water heater for incoming power.
1) Turn the Power OFF at the circuit breaker and lock the breaker switch in the off position, and/or disconnect the power using the electrical switch or disconnect box.
2) MAKE SURE THE POWER IS OFF! Test the incoming power to the AO Smith water heater. Using a screwdriver, take the upper panel off of the front of the water heater, and remove the insulation and plastic cover. Be very careful not to touch any wires until you have tested for certain that they are not live! After you have exposed the thermostat, element and wires, you should see something very similar to the picture on the right. AO Smith Electric Water Heater Troubleshooting & Repair Guide In the photo to the left, you will see 7 terminals on the thermostat or t-stat for short. Then you will see the element below that with two terminals. Test the incoming power using a voltmeter on the upper two terminals on the electrical thermostat. If the power is off it should read around zero volts. If the power is on you will get a reading of 240 volts across the two upper terminals. If you have power to the water heater when all the breakers and switches are on, but still no hot water, then you will have to continue testing to troubleshoot exactly which component is broken. There are only four components to the electrical heating system. The upper thermostat and upper element, and the lower thermostat and lower element.
3) How to test and replace AO Smith Water Heater Elements.
Make sure there is no power coming to the upper terminals. Open both the lower cover and the upper cover. The lower port once opened will look very similar to the upper port. A photo of the lower t-stat and lower element are on the right. Youll notice only two (or sometimes three) terminals on the lower t-stat and two terminals on the lower element. With the power off and disconnected, use a screwdriver to remove the wires from the two element terminals of the upper element. Using an ohm meter to test the electrical resistance of the element is the safest, simplest way to troubleshoot wether the element is burned or not. Use the ohm meter and measure by touching each poles of the ohm tester to each of the terminals on the element.
A bad element will give you a very high reading because they element is broken, and the resistance is very high. A good element will give you a low reading of around 12-14 ohms. Now test the lower element the same way as the upper, after disconnecting the wires from the element terminals. If you dont disconnect the wires from the element, then the wires will interfere with the resistance test and resistance will read as zero.
If youve tested both elements and one of them is bad, you will have to drain the AO Smith water heater using a garden hose, and remove the bad element using an element socket wrench and install a new element. If neither element is bad, then one of the thermostats must be malfunctioning.
4) How to Test and replace AO Smith Water Heater Thermostats.
Testing the thermostats is a little more dangerous, because they have to be tested live! So be very careful or hire a professional. Reconnect the wires to the elements. Turn the power on to the water heater and use a small screwdriver to turn the upper t-stat all the way up. Now use your voltmeter to test that the upper t-stat is sending power to the upper element. It should read 240 volts across both terminals together, or 120 volts on each terminal.
If the upper t-stat is sending power to the upper element, then turn the upper t-stat all the way down and make sure it shuts off. Then, repeat the t-stat test you just completed on the upper t-stat by testing the lower t-stat the same way. If one or both of the t-stats is not switching on, it wont send any power to the associated element, so you will have to disconnect the power, disconnect the wires, remove the bad t-stat and install a new one. Make sure to pay attention to the wiring, and the new wiring diagram that comes with the new t-stat.