For proper operation, the spa thermostat must be located in the plumbing between the suction point and the heater-- never after the heater. The spa thermostat consists of a rotating control for setting the temperature level, such as a thermostat knob, and a capillary tube with a bulb attached for remotely picking up the spa water temperature. The sensor bulb is often housed in a protective thermowell.
We can supply you with spa thermostats and thermostat knobs at the lowest prices. If you can't find what you're looking for, feel free to give us a call at 800.544.3730