The E3 Error indicates a condition where the Temperature Sensor has sensed a high temperature (Greater than 113 F. / 45 C.) within the PCU before the water has passed through the Heater. E3 will disable all functions and requires the PCU to be Reset (see solution) to clear once the temperature is within safe use range.
Due to the sensitive nature of the sensors and control electronics it is possible that the error code was triggered by a surge in the supply power, a momentary loss of supply power or even the effect of lightning. Anytime an error code appears first perform the PCU RESET - Plug in the GFCI - then Press the TEST BUTTON on the GFCI - wait 5 seconds -then press the RESET BUTTON. This will reset the PCU, if the error code returns then you will need to follow the corrective steps for that code.
A possible cause can be a restriction in the flow from the Discharge of the PCU. Check the Discharge Port in the Hot Tub for obstructions in the openings and make sure the Clear Cap has been removed. Check the Piping from the Discharge Port on the PCU to the Discharge Port on the Hot Tub, make sure it is straight and not kinked.
Be sure the Cover Cap has been removed and check the Discharge Port for obstructions in the openings.
Check the Piping from the Heater Discharge Port to the Hot Tub. The Pipe should be straight and not kinked or collapsed.
Do Not Block or Restrict the Flow of the Intake or Discharge Ports located inside the Hot Tub. This will cause Faults and Performance issues with the PCU.
Another possible cause is the temperature of the water in the Hot Tub has reached 113 F. / 45 C. Filling the Hot Tub directly from the Household Hot Water system could potentially reach this temperature. If this is the cause then drain the hot water and add cold water enough to lower the temperature below 104 F. / 40 C.
If the water temperature added to the Hot Tub and PCU was over 116 F. / 47 C. it will cause the E3 and the High Limit Breaker to trip. You will need to unplug the GFCI, turn the PCU over and insert a thin 4" rod into the hole marked "Reset".
If the E3 Error still appears the next step is to determine if the sensor is reading correctly. Cap the Intake and Discharge Ports in the Hot Tub and remove the Filter Bowl Lid. Use a thermometer to check the temperature of the water sitting in the Filter Bowl. RESET the GFCI and check the Temperature reading on the PCU display. If the PCU shows E3 right away and the reading you see with your thermometer is below 113 F. / 45 C. and / or the water in the Filter Bowl is not hot then the PCU will need to be replaced.
If you require any further assistance, please contact Customer Service.