Determine Tank Temperature
Thermal Well Testing (cont’d)
Determine the correct resistance values using the Determine the Water Temperature Inside the Tank procedure on page 23. If the values are correct, replace the gas control, otherwise replace the thermal well.
Determine Water Temperature Inside Tank
WARNING
Stored water may be HOT when performing the following steps in this procedure. Take necessary precaution to prevent personal injury.
Note: It is important to understand once the resistance for the thermal well is determined using the Thermal Well Testing Procedure on page 21, water flow through the water heater should not occur. Prior to performing the steps below, turn off the cold water supply to the water heater. This will prevent cold water flow into the tank affecting the resistance value of thermal well.
Step 1. Move the gas control power switch to the “OFF” position.
Gas control power
switch
Step 2. Draw approximately 4 gallons of water from the drain valve into a container and discard. Draw an additional gallon and immediately measure the water temperature using an accurate thermometer. It may be necessary to open a hot water faucet to allow heater to drain.
Step 3. Using the chart on page 23, determine the correct resistance value for the water temperature from Step 2.
Example: If temperature of water is 84°F, then the resistance through the sensor
would be 8449 (see shaded area). NOTE: Sensor resistance increases as the temperature falls.
Page 22
22
