The primary tank liquid level sensor detects water level, activating the primary heater element. The liquid level sensor is enclosed in a slosh tube and wired to a 30-second time delay, to eliminate heater contactor chatter during crane movement. If primary tank overflow occurs, an amber light warns operator. The secondary tank utilizes the same control logic as the primary tank. A high water level sensor will activate a red light and shut the air conditioner down through an air conditioner interlock relay. Each tank is equipped with an over-temperature thermostat to protect heater elements from burning out.