Pressure switch is a safety device. It turns off the heater when there is low pressure, no flow or decreased water flow.
The hot tub pressure switch can be attached to the heater or externally attached to the plumbing. The purpose of the pressure switch is to monitor the heater, plumbing for proper water pressure and to shut off the heater in the event pressure is not maintained.
The hot tub pressure switch assures that there is a continuous flow of cooling water to avoid overheating of the heater element. This safety feature avoids heater failures.
The contacts on the pressure switch open when a flow problem is detected and close during normal operation. If this occur, on some control panels an error code will be displayed “FLO” or “FLC”.
Pressure switches can be adjusted for sensitivity by a thumbwheel on the pressure switch but they do come pre-calibrated.