Home / Wiring / CIT-1 At what temperature does the CIT-1 sensor activate? CIT-1 The CIT-1 sensor activates when temperatures drop to 38 degrees or less. Underfloor Heating Thermostats Heated Floors Further Questions? Installation - How far from the controller can the CIT-1 sensor be placed? - Installation of the CIT-1 Miscellaneous questions - At what temperature does the CIT-1 sensor activate? Wiring - What gauge wire should be used for the CIT-1? - Is the CIT-1 sensor high or low voltage?