Step 1. Set the gas control knob to the “OFF” position. Turn off inlet water supply to water heater.
Step 2. Draw approximately 4 gallons of water from drain valve into a container, or suitable drain, and discard. Draw an additional gallon and immediately measure water temperature using an accurate thermometer. It may be necessary to open a hot water faucet to allow water heater to drain.
Step 3. Using the chart below, determine 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 decreases.