How to Test a Water Heater Element for Optimal Performance: A Step-by-Step Guide

Are you wondering how to test a water heater element? And you find it difficult to test? here is what to do.

before we enter our topic you may know the element of a water heater which are Line Voltage & High Limit (ECO) – Heating Element – Residential Thermostat –Light Duty Commercial Thermostat.

we’ll talk about all these elements please follow these all instructions and steps to know how to test a water heater element:

How to test Line Voltage & High Limit (ECO)?

1) line voltage

1. Turn “OFF” power to the water heater.

2. Remove access cover(s) from the front of a water heater. Remove insulation and plastic cover from the thermostat.

3. Set multi-meter to volts AC.

4. Turn power “ON” to the water heater.

5. Check voltage

Rated voltage IS present, power to the water heater is okay.

Rated voltage NOT present, Check circuit breaker at the service panel.

2) High Limit (ECO) Testing

1. Check voltage across terminals

Rated Voltage IS present, ECO is okay.

Rated voltage NOT present.

2. Turn power “OFF” to the water heater and firmly press the ECO reset button on the thermostat(s). Turn power “ON” and recheck voltage

3. Rated voltage IS present, the ECO has opened indicating the water in the tank is or has over the heater. Check the following:

Thermostat must be in full contact with the tank.

Be sure heating element(s) is not shorted to ground.

Proper thermostat operation

4. Rated voltage NOT present, water in the tank may be overheated.

If water is hot, turn “OFF” power to the water heater and flow water through the tank to cool below the set point of the upper thermostat.

If water is cool, Replace the upper thermostat.

How to test Heating Element?

1) Testing For Open Or Burned Out Element.

Step 1. TURN OFF POWER TO WATER HEATER.

Step 2. Remove access cover(s) from the front of the water heater. Remove insulation and plastic cover from the thermostat.

Step 3. Disconnect wires from the heating element.

Step 4. Set multimeter to “ohms” setting.

Step 5. Touch probes of multi-meter to screw terminals of the heating element.

Step 6. Reading should be 12.8 ohms (±6%) for a 240 volt, 4500-watt element:

ohms = volts2/watts

A reading outside the range using the formula above (±6%), indicates a bad element and the element must be replaced.

2) Testing For Heating Element Short Circuit To Ground.

Step 1. TURN OFF POWER TO WATER HEATER.

Step 2. Remove access cover(s) from the front of the water heater. Remove insulation and plastic cover from the thermostat.

Step 3. Disconnect wires from the heating element.

Step 4. Set multimeter to “ohms” setting.

Step 5.

Touch one probe of multi-meter to either screw terminal of the heating element and the other on the element flange There should be no reading on the ohmmeter.

Any reading indicates a grounded element and the element must be replaced.

Repeat this step for the other screw terminal.

How to test Residential Thermostat?

Single Element Operation or Double Element, 4 Wire, Simultaneous, Single Phase Operation.

1) Water In Tank Is Cold With Power ON.

1. This procedure assumes line voltage, ECO, and elements are in working order.

2. Turn power “ON” to the water heater.

3. Set multimeter to “Volts AC”.

4. Check :

Rated voltage NOT present, Recheck ECO. If ECO is okay, replace the thermostat.

Rated voltage IS present, proceed to the next step.

5. Check :

Rated voltage NOT present, check wire connections from the thermostat to element.

Rated voltage IS present, Repeat element testing

2) Water Temperature In Tank Is Above Thermostat Setting.

1. This procedure assumes line voltage, ECO, and elements are in working order.

2. Turn power “ON” to the water heater.

3. Set multimeter to “Volts AC”.

4. check:

Rated voltage IS present, replace the thermostat.

Rated voltage NOT present, thermostat is okay.

Lower than rated voltage IS present, recheck for grounded element

Double Element, Non-Simultaneous, Single Phase Operation.

1) Water In Tank Is Cold With Power ON.

1. This procedure assumes line voltage, ECO, and elements are in working order.

2. Turn power “ON” to the water heater.

3. Set multimeter to “Volts AC”.

4. Check :

Rated voltage NOT present, Recheck ECO. If ECO is okay, replace the thermostat.

Rated voltage IS present, proceed to the next step.

5. Check :

Rated voltage NOT present, check wire connections from the thermostat to element.

Rated voltage IS present, Repeat element testing.

2) Tank Does Not Deliver Enough Hot Water

1. This procedure assumes line voltage, ECO, and elements are in working order.

2. Turn power “ON” to the water heater and set multi-meter to “Volts AC”.

3. Adjust the temperature setting of the upper thermostat to the highest setting. Water temperature in the tank must be below the thermostat setting for this test.

4. Check :

Rated voltage IS present, okay, the upper thermostat is calling for heat.

Rated voltage NOT present, replace the upper thermostat.

5. Adjust the temperature setting of the upper thermostat to the minimum setting. Water temperature in the tank must be above the thermostat setting for this test.

6. Check :

Rated voltage NOT present, replace the upper thermostat.

Rated voltage IS present, the thermostat is okay.

7. Check :

Rated voltage NOT present, – check wire connection between thermostats.

Rated voltage IS present.

8. Adjust the lower thermostat to the highest setting. Water temperature in the tank must be below the lower thermostat setting for this test.

9. check:

Rated voltage NOT present, replace the lower thermostat.

Rated voltage IS present, the thermostat is ok

3) Water Temperature In Tank Is Above Thermostat Setting.

1. This procedure assumes line voltage, ECO, and elements are in working order.

2. Adjust upper and lower thermostats to the lowest setting.

3. Turn power “ON” to the water heater and set the multimeter to “Volts AC”.

4. Check:

Rated voltage IS present, replace the upper thermostat.

Rated voltage NOT present, the upper thermostat is okay.

Lower than rated voltage IS present, recheck for grounded upper element.

5. Check :

Rated voltage IS present, replace the lower thermostat.

Rated voltage NOT present, lower thermostat is okay.

Lower than rated voltage IS present, recheck for the grounded lower element.

Double Element, Non-Simultaneous, Three Phase Operation.

A: Water In Tank Is Cold With Power ON.

1. This procedure assumes line voltage, ECO, and elements are in working order.

2. Turn power “ON” to the water heater.

3. Set multimeter to “Volts AC”.

4. Check:

Rated voltage NOT present, Recheck ECO. If ECO is okay, replace the thermostat.

Rated voltage IS present.

5. Check:

Rated voltage NOT present, check wire connections from the thermostat to element.

Rated voltage IS present, Repeat element testing.

1) Tank Does Not Deliver Enough Hot Water.

1. This procedure assumes line voltage, ECO, and elements are in working order.

2. Turn power “ON” to the water heater and set the multimeter to “Volts AC”.

3. Adjust the temperature setting of the upper thermostat to the highest setting. Water temperature in the tank must be below the thermostat setting for this test.

4. check:

Rated voltage IS present, okay, the upper thermostat is calling for heat.

Rated voltage NOT present, replace the upper thermostat.

5. Adjust the temperature setting of the upper thermostat to the minimum setting. Water temperature in the tank must be above the thermostat setting for this test.

6. Check:

Rated voltage NOT present, replace the upper thermostat.

Rated voltage IS present, the upper thermostat is okay.

7. Check :

Rated voltage NOT present, check wire connection between thermostats.

Rated voltage is present, okay

8. Adjust the lower thermostat to the highest setting. Water temperature in the tank must be below the lower thermostat setting for this test.

9. Check:

Rated voltage NOT present, recheck ECO. If ECO is okay, replace the lower thermostat
Rated voltage IS present, the thermostat is ok. Check wire connection to lower element. If the connection is okay, recheck the lower element

How to test light Duty Commercial Thermostat?

Double Element, Non-Simultaneous, Single Phase Operation.

1) Water In Tank Is Cold With Power ON.

1. This procedure assumes line voltage, ECO, and elements are in working order.

2. Turn power “ON” to the water heater.

3. Set multimeter to “Volts AC”.

4. check :

Rated voltage NOT present, Recheck. If ECO is okay, replace thermostat.

Rated voltage IS present.

5. Check:

Rated voltage NOT present, check wire connections from the thermostat to element.

Rated voltage IS present, Repeat element testing

2) Tank Does Not Deliver Enough Hot Water.

1. This procedure assumes line voltage, ECO, and elements are in working order.

2. Turn power “ON” to the water heater and set multi-meter to “Volts AC”

3. Adjust temperature setting of upper & lower thermostat to the Highest setting. Water temperature in the tank must be below the thermostat setting for this test.

4. check :

Rated voltage IS present, okay, the upper thermostat is calling for heat.

Rated voltage NOT present, replace the upper thermostat.

5. Adjust the temperature setting of the upper thermostat to the minimum setting. Water temperature in the tank must be above the thermostat setting for this test.

6. Check:

Rated voltage NOT present, replace upper thermostat.

Rated voltage IS present, the upper thermostat is okay.

7. check:

Rated voltage NOT present, Replace lower thermostat.

Rated voltage is present, okay

8. Check voltage across the lower element

Rated voltage NOT present, Check wire connections between thermostats & elements.

Rated voltage IS present, Repeat element testing

3) Water Temperature In Tank Is Above Thermostat Setting.

1. This procedure assumes line voltage, ECO, and elements are in working order.

2, Adjust the upper and lower thermostat to the lowest setting.

3. Turn power “ON” to the water heater and Set multimeter to “Volts AC”

4. check:

Rated voltage IS present, replace lower thermostat.

Rated voltage NOT present, okay.

Lower than rated voltage IS present, recheck for the grounded lower element.

5. Check:

Rated voltage NOT present, upper thermostat is okay.

lower than rated voltage IS present, recheck for grounded upper element.

Double Element, Simultaneous, Single Phase Operation.

1) Water In Tank Is Cold With Power ON.

1. This procedure assumes line voltage, ECO, and elements are in working order.

2. Turn power “ON” to the water heater.

3. Set multimeter to “Volts AC”.

4. check :

Rated voltage NOT present, Recheck. If ECO is okay, replace thermostat.

Rated voltage IS present.

5. Check:

Rated voltage NOT present, check wire connections from the thermostat to element.

Rated voltage IS present, Repeat element testing

2) Tank Does Not Deliver Enough Hot Water.

1. This procedure assumes line voltage, ECO, and elements are in working order.

2. Turn power “ON” to the water heater and set multi-meter to “Volts AC”

3. Adjust temperature setting of upper & lower thermostat to the Highest setting. Water temperature in the tank must be below the thermostat setting for this test.

4. check :

Rated voltage IS present, okay, the upper thermostat is calling for heat.

Rated voltage NOT present, replace the upper thermostat.

5. Adjust the temperature setting of the upper thermostat to the minimum setting. Water temperature in the tank must be above the thermostat setting for this test.

6. Check:

Rated voltage NOT present, replace the upper thermostat.

Rated voltage IS present, the upper thermostat is okay.

7. check:

Rated voltage NOT present, Replace lower thermostat.

Rated voltage is present, okay

8. Check voltage across the lower element

Rated voltage NOT present, Check wire connections between thermostats & elements.

Rated voltage IS present, Repeat element testing.

3) Water Temperature In Tank Is Above Thermostat Setting.

1. This procedure assumes line voltage, ECO, and elements are in working order.

2, Adjust the upper and lower thermostat to the lowest setting.

3. Turn power “ON” to the water heater and Set multimeter to “Volts AC”

4. check:

Rated voltage IS present, replace the lower thermostat.

Rated voltage NOT present, okay

Lower than rated voltage IS present, recheck for the grounded lower element.

5. Check:

Rated voltage NOT present, upper thermostat is okay.

lower than rated voltage IS present, recheck for grounded upper element.

6. Check :

Rated voltage IS present, replace lower thermostat.

Rated voltage NOT present, lower thermostat is okay.

lower than rated voltage IS present, recheck for grounded lower element.

After you read and follow the instructions above you might now have the answer to how to test a water heater element?