A: This is a sensor break or over-range. Unplug the thermocouple. If the error remains, the input chip is fried (often due to high voltage leaking from the heater into the sensor).
: The operating mode can be toggled between "Heat" and "Cool" in the configuration menu. An "outlamp" typically indicates when the heating relay is energized. thermotech tt91 manual hot
Holding the manual key (typically M ) for more than 2 seconds can switch the unit between manual and automatic control. A: This is a sensor break or over-range
: Press and hold the UP arrow key for several seconds until the display flashes "tUnE" . thermotech tt91 manual hot
Use the and DOWN arrow keys on the front panel to adjust the SV to your desired "hot" setting. Select Heating Mode: