Lo and Hi Message on the Fireplace Control Unit

If the probe reading is below the minimum limit of the operating range, the display shows the message “Lo”.
In these cases, the most common cause is a missing or incorrect connection of the probe, which causes the control unit to detect a temperature of 0 °C.
Carefully check the probe wiring. If the problem persists, proceed with the replacement of the control unit.

If the probe reading is above the maximum limit of the range, the display shows the message “Hi”.
This is usually due to a short-circuited probe or a fault in the dedicated output of the control unit.
In this case, replace the probe. If the anomaly persists, also replace the control unit.