This DIP Switch setting indicates which method of outdoor sensing is being utilized for automatic brick core charge regulation in the heater. When this switch is in the "OFF" position, the heater will only accept outdoor temperature information via Power Line Carrier signals. When the DIP Switch is in the "ON" position, a direct wired Outdoor Sensor must be connected to the room heating unit.
OFF = Power Line Carrier signal is used for automatic brick core charge regulation
ON = low voltage (direct wired) Outdoor Temperature Sensor is connected to the heater for automatic brick core regulation
NOTE: If Automatic Charge Control is not utilized, this DIP Switch should remain in the "OFF" position. If this DIP Switch is in the "ON" position; and, there is not an outdoor sensor connected directly to the circuit board, the room heating unit will go into an "EO8" mode and will not function.