The present invention provides a system for detecting an amount of A2L refrigerant in an air temperature controller using an A2L refrigerant, and a method of installing a configuration of A2L sensors in the air temperature controller using an A2L refrigerant. The system includes an A2L control board, a first A2L sensor, and a second A2L sensor. The first A2L sensor and the second A2L sensor are coupled in series and electrically coupled to the A2L control board. Each of the first A2L sensor and the second A2L sensor include sensing components configured to detect the amount of A2L refrigerant.