Spa Everdure Controller Has Duel Air Switch HIGH LIMIT Temperature Sensor With Solenoid.
With the addition of two air operated switches,
One for control of the spa pump which is interlocked with the heater circuit and a second one for an auxiliary piece of equipment such as a blower or a light etc,
This device is used for manual operation of the spa from an Air Button: when the pump is turned on the unit will allow the heater to come on if heat is required up to a maximum user pre-set temperature of 40°C.
In addition to this user adjustable control the unit also provides HIGH LIMIT protection at 45°C, when correctly installed, by removing power to the spa pump if an over temperature situation occurs