This is the replacement thermistor for the 1999-2002 Hot Spot RE, RLX, SE, SLX, and the 2001-2002 SLXtra (wood-sided) spa models. Also the Solana 2000-2002 X, 2003-2005 RX, SX, and TX models. This thermistor communicates the actual water temperature to the controller to shut off the heater when the spa reaches the target temperature.
Note: The topside control panel will display “Prr” which indicates that this part has failed.
1. Set the meter to 20K on the OHM scale.
2. Record the temperature of the spa water.
3. Unplug the thermistor from the control box.
4. Meter across the two Thermistor leads.
5. Refer to the Temperature versus Resistance chart to find the correct resistance value for the temperature measured. If the temperature and resistance do not match that of the chart, this test has failed and the thermistor must be replaced. Remember if the spa has been inactive, the spa water temperature may be different
than the water temperature in the heater housing.