Reliance water heater displays E6 and does not heat properly.

Safety first: Disconnect power and shut off the gas. Allow the tank to cool before removing any sensor or access covers.

Steps to check:

• 1. Access tank sensor: Remove the front panel and insulation as needed to locate the tank temperature sensor (often inserted into a well on the tank wall).
• 2. Inspect for moisture: Look for signs of water leakage around the sensor well or wiring grommet. Any leak must be corrected before replacing electronic components.
• 3. Check wiring: Follow the harness to the control board. Reseat connectors and inspect for corrosion or damage.
• 4. Test sensor resistance: Disconnect the sensor and measure resistance with a multimeter. Compare it to Reliance’s chart. Replace the sensor if the readings are out of range.
• 5. Reinstall properly: When installing a new sensor, ensure it is fully seated in the well and that any thermal compound or gasket is correctly applied to ensure accurate readings.

Note: If there is evidence of tank wall leakage at the sensor well, the tank itself may be compromised and require replacement.