View with plastic shock protector removed: {“smallUrl”:“https://www. wikihow. com/images/thumb/7/74/Waterheater_003_493. jpg/460px-Waterheater_003_493. jpg”,“bigUrl”:"/images/thumb/7/74/Waterheater_003_493. jpg/374px-Waterheater_003_493. jpg",“smallWidth”:460,“smallHeight”:687,“bigWidth”:375,“bigHeight”:560,“licensing”:"<div class="mw-parser-output">

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Rust coats wires and controls - both outside and inside {“smallUrl”:“https://www. wikihow. com/images/thumb/6/6e/1rustbot. JPG/460px-1rustbot. JPG”,“bigUrl”:"/images/thumb/6/6e/1rustbot. JPG/420px-1rustbot. JPG",“smallWidth”:460,“smallHeight”:613,“bigWidth”:420,“bigHeight”:560,“licensing”:"<div class="mw-parser-output">

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<br />\n</p></div>"} Rust is conductive - even when on the wire insulation. This can lead to potentially deadly shocks, heating and melting insulation and even burns. Sooty, black carbon deposits on surfaces indicate a short circuit. Chances are there is an exposed copper wire that may be difficult to see due to the carbon deposits that resulted from the short circuit. Wires may have been damaged and now suffer with a reduced circumference that is needed to safely carry the heating element electrical load. This point of damage also becomes a source of heat. It is very important to repair or replace all parts that have visible forms of water and short circuit damage. This includes wires, wire insulation, jumpers and the controls themselves. As mentioned above, rust is a conductor and provides unintended and unexpected paths for electricity. These unintended paths can be dangerous and make troubleshooting very difficult to perform. Here, the yellow wire between the control and element appears to have shorted to the tank (or other metal) leaving a sooty black deposit on the wire and above. Notice the lower left terminal of the thermostat. Excessive heat has caused the plastic around the terminal to begin to melt. {“smallUrl”:“https://www. wikihow. com/images/8/8f/1rusttop. JPG”,“bigUrl”:"/images/thumb/8/8f/1rusttop. JPG/420px-1rusttop. JPG",“smallWidth”:460,“smallHeight”:613,“bigWidth”:420,“bigHeight”:560,“licensing”:"<div class="mw-parser-output">

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High Temperature Limit Switch: Has a reset button There will be (4) terminal screws / wires connected to it. Usually, the top two terminals have wires that go up to the field wiring compartment that bring the power to the rest of the water heater’s controls and heating elements. The “upper controls” consist of the High-Temperature Limit Switch and Upper Thermostat. The “lower controls” refers to the Lower Thermostat (there is no High-Temperature Limit Switch for the lower section of most electric water heaters). Three of the four terminals are numbered and visible in the picture (#1, #3, & #4; the #2 terminal is not identified as it is connected directly to the thermostat below via factory installed jumper). {“smallUrl”:“https://www. wikihow. com/images/thumb/2/24/Waterheater_006_515. jpg/460px-Waterheater_006_515. jpg”,“bigUrl”:"/images/thumb/2/24/Waterheater_006_515. jpg/374px-Waterheater_006_515. jpg",“smallWidth”:460,“smallHeight”:687,“bigWidth”:375,“bigHeight”:560,“licensing”:"<div class="mw-parser-output">

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\nLicense: <a target="_blank" rel="nofollow noreferrer noopener" class="external text" href="https://creativecommons. org/licenses/by/3. 0/">Creative Commons</a>\n</p></div>"} Thermostat: Has a graduated, adjustable dial. The dial may indicate letters “A” “B” “C” etc. , “warm, hot and hotter” or as in the case of the one pictured, the actual temperature in degrees. The thermostat is located just below the High Temp Limit Switch. {“smallUrl”:“https://www. wikihow. com/images/thumb/0/05/Waterheater_007_779. jpg/460px-Waterheater_007_779. jpg”,“bigUrl”:"/images/thumb/0/05/Waterheater_007_779. jpg/374px-Waterheater_007_779. jpg",“smallWidth”:460,“smallHeight”:687,“bigWidth”:375,“bigHeight”:560,“licensing”:"<div class="mw-parser-output">

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\nLicense: <a target="_blank" rel="nofollow noreferrer noopener" class="external text" href="https://creativecommons. org/licenses/by/3. 0/">Creative Commons</a>\n</p></div>"} Heating Element: Has two terminals with a wire connected to each. One of these wires is usually connected to the thermostat associated it (in these photos the thermostat is directly above it). It is usually located below the controls and supports the controls with a clip of some type (in this photo, it has two terminals and a gray metal clip attached to support the controls above). {“smallUrl”:“https://www. wikihow. com/images/thumb/a/a4/Waterheater_008_693. jpg/460px-Waterheater_008_693. jpg”,“bigUrl”:"/images/thumb/a/a4/Waterheater_008_693. jpg/374px-Waterheater_008_693. jpg",“smallWidth”:460,“smallHeight”:687,“bigWidth”:375,“bigHeight”:560,“licensing”:"<div class="mw-parser-output">

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In the provided picture, the meter indicates 0. 078 volts present. This is less than 1/10 of a volt, and is considered “off”.

In the example picture, the meter indicates 0. 2 ohms resistance - or zero. The meter can not display a value lower than this value, since there is no zero adjust feature it is considered 0.

In the example picture, the meter indicates 0. 2 ohms resistance - or zero. The meter can not display a value lower than this value, since there is no zero adjust feature it is considered 0.

In the provided picture, the meter indicates 12. 5 ohms resistance, and since is within acceptable limits of the calculated 12. 2 ohms value, it is considered “good”.

The picture displays the “nameplate” information of the water heater. Two different wattage ratings are provided (4500 / 4500 and 3500 / 3500). The “4500 / 4500” rating is the wattage rating for the upper and lower element respectively, when connected to a 240 volt supply. Alternatively, the “3500 / 3500” rating is the wattage of the upper and lower element respectively, when connected to a 208 volt supply. Most residential applications are 240 volts, but 208 volt and 120 volt types are also found.

Lower access panels removed, exposing the plastic shock protector: {“smallUrl”:“https://www. wikihow. com/images/thumb/c/c2/Waterheater_004_860. jpg/460px-Waterheater_004_860. jpg”,“bigUrl”:"/images/thumb/c/c2/Waterheater_004_860. jpg/374px-Waterheater_004_860. jpg",“smallWidth”:460,“smallHeight”:687,“bigWidth”:375,“bigHeight”:560,“licensing”:"<div class="mw-parser-output">

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\nLicense: <a target="_blank" rel="nofollow noreferrer noopener" class="external text" href="https://creativecommons. org/licenses/by/3. 0/">Creative Commons</a>\n</p></div>"} #* Remove protector as done for upper access point above to expose the terminals. Notice that there is no reset button (high limit) on the like the top: {“smallUrl”:“https://www. wikihow. com/images/thumb/7/77/Waterheater_005_473. jpg/460px-Waterheater_005_473. jpg”,“bigUrl”:"/images/thumb/7/77/Waterheater_005_473. jpg/374px-Waterheater_005_473. jpg",“smallWidth”:460,“smallHeight”:687,“bigWidth”:375,“bigHeight”:560,“licensing”:"<div class="mw-parser-output">

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Lower access panels removed, exposing the plastic shock protector: {“smallUrl”:“https://www. wikihow. com/images/thumb/c/c2/Waterheater_004_860. jpg/460px-Waterheater_004_860. jpg”,“bigUrl”:"/images/thumb/c/c2/Waterheater_004_860. jpg/374px-Waterheater_004_860. jpg",“smallWidth”:460,“smallHeight”:687,“bigWidth”:375,“bigHeight”:560,“licensing”:"<div class="mw-parser-output">

Image by: Uploader
\nLicense: <a target="_blank" rel="nofollow noreferrer noopener" class="external text" href="https://creativecommons. org/licenses/by/3. 0/">Creative Commons</a>\n</p></div>"} #* Remove protector as done for upper access point above to expose the terminals. Notice that there is no reset button (high limit) on the like the top: {“smallUrl”:“https://www. wikihow. com/images/thumb/7/77/Waterheater_005_473. jpg/460px-Waterheater_005_473. jpg”,“bigUrl”:"/images/thumb/7/77/Waterheater_005_473. jpg/374px-Waterheater_005_473. jpg",“smallWidth”:460,“smallHeight”:687,“bigWidth”:375,“bigHeight”:560,“licensing”:"<div class="mw-parser-output">

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The line voltage in the system under test is 208 volts. Since 203 is within a few percent of 208, this example indicates full power available to the element and if it passed the resistance or ohms test above - is heating the water in the tank.