High-limit Aquastat® immersion type controllers for regulating and limiting the tank temperature in water heater and hrdronic systems. As the water temperature rises past the setpoint, the controller switches off the gas valve.

• Regulates temperature and provides energy cutoff (ECO) action on a temperature rise past the setpoint
• Includes a second sensing element that senses average water temperature to minimize stacking
• Fluid-filled element operates Micro Switch™ SPST snap-acting switch
• ECO switch interrupts the thermocouple circuit or main valve before tank reaches 210 F (99 C) maximum temperature
• Includes factory-installed immersion well on controller
• Internal adjustment screw
• Special switch terminal provides three-wire hookup from Aquastat® controller to gas valve