If your Spa is no longer reaching and keeping the set temperature even when is set to Ready or Standard Mode, there might be some issues with the heater or board. To confirm if the heater would be the cause of the issue, you can measure the voltage coming out from the Control System and Heater tube.
NOTE: Please note that you should only be doing these testings if you are trained for it and completely understand the procedure of measuring voltage. Exercise extreme caution at all times.
1. Remove the front cabinet panels and once you have located the Control System, remove the lid to expose the wiring.
2. Using a Voltmeter, proceed to measure the incoming voltage on the 2 hot wires in the terminal block. If you get a voltage of 210-220V, that would indicate the voltage there is correct.
2. Next, proceed to measure voltage between each of the hot wires with the top one and if you get on both cases a voltage around 110V-120V, that means you are getting a correct voltage.
3. Next step would be to test the voltage across the heater tube. To do so, the heat light on the topside must be ON so you would need to increase the set temperature to force the heater to turn ON. Please note that when the heat light first come ON, it would blink for some seconds while the heater is warming up and trying to read the current temperature of the water to start heating. Once the heater has turned ON, the heat light will become solid.
4. Once the heat light has turned solid ON (no blinking), you can proceed to test voltage across the heater tube by placing the voltmeter on the heater terminals. If the heater is properly working, you should get a voltage around 205-210V.
5. As an additional testing, you can test voltage between each heater terminal and the neutral wire on the board to ensure you are getting 110-120V.
If you have got all readings within the values above, then you can ensure your heater is working properly and the issue is most likely with the board.
To watch a video showing how to properly test the Heater Voltage, click HERE.