Thanks for the advice. I forgot to mention that I did actually do that a few times and the highest reading I received was 98. (I will check it again tonight though!) If in fact it is the thermostat on the spa, is there any type of adjustment I can make to it? I searched the forums and it seems like a relatively good option would be to add in a resistor to the thermostat wiring. I would rather explore other options first before jumping to that.