Thermistors- XLRG Inlet (original series)

**Note: If your unit currently has no thermistor connected and is being used, understand that this is not optimal for your unit, and one should use the hot water sparingly. Once your new set arrives, you can replace the thermistors and use your unit as needed.   Description: Thermistors w/ O-ring Model #: THRM QC MEDLRG INLET Only (Original Series) Compatible With: model 18,21,36kW Shipping Details: ** Any parts sold after 3pm EST M-F may be shipped next day.