Use caution when bypassing a hot tub thermostat to avoid dangerous water temperatures.
These thermostats usually have high and low temperature limits that correspond to safe water temperatures and are preset at the factory to a comfortable level. If you wish to bypass the thermostat on a hot tub, however, the process is simple. Remember that very high water temperatures may be unsafe and are not recommended for more than a few minutes at a time.
Turn off the hot tub and disconnect the power from the power cord or at the circuit breaker.
Open the hot tub access panel and locate the thermostat, which looks like a control knob connected to a copper wire.
Rotate the adjustment screw on the bottom of the thermostat with an Allen wrench. Turn clockwise to increase the thermostat temperature or counterclockwise to decrease the thermostat temperature.