Thermospa hot tub how do increase the grill over 104 degree?
Answers: Doubtful you can override the inbuilt temperature control. They set them for max 104 for sanctuary reasons and permissible liability issues. Anything over that runs the risk of injury for some people and small children. If you internally run a temp of 104 for too long you would be considered a sick cookie. If you sat within a 108, say, hot tub for too long you could make higher your core temp to dangerous level, depending on your health status, meds, age, etc.
others are correct, 104 is as illustrious as you can go. The control will one and only let you hold it to 104 but if you did manage to seize the temp up higher than that, the spa will not turn on because it will "think" here is a malfunction next to the thermostat.