Cause  The water is not heated or the temperature in the tub is overheated to over 194º F

Solution

1)   Check wire connection.

2)   Check the water temperature.  If the temperature is less than 120º F the customer will need to adjust hot water temperature supplied to the unit.

3)   Check the electric resistance of thermistor. Resistance should be between 8k ~ 44k ohms depending on temperature. It should read 12.7k @ 70º F.

If out of range then replace thermistor.

4)   Check the resistance of Heater. It should read between 11~13 ohms. If out of range replace the heater.

5)   Check voltage to the heater for 120 volts ac. If heater does not get 120 volts ac during heater test then replace Main PCB.