Operating Temperature Sensor or DHW Sensor detects Water Temperature Greater than 199ºF (93ºC).
This Error Code will go away when the DHW temperature decreases.
If Error happens again:
- Check if dip switch High Fire setting is ON. Switches 6 and 7 should be OFF for normal operation.
- Check if DHW pipe is blocked. Ensure there is enough water flowing to the water heater.
- Check DHW sensor at DHW outlet. If resistance is zero, replace the sensor.
- Check Operating Temperature sensor at the heat exchanger. If resistance is zero, replace the sensor.
- If the problem persists, replace the main control.
