Hot tub temp sensors for Balboa, Gecko
If you find that your hot tub does not register the correct temperature on the top side display, you may need to replace the temp sensor to correct this.
An easy diagnoses is to remove the temp sensor and place in a container of hot water making sure you know the correct temperature. Once you have left the temp sensor in the water for 2 minutes check the top side display reading and compare with the thermometer in the container.
If you have a discrepancy between the two then replace the temp sensor with a new one.