E37

Outdoor Unit Heat Exchanger Sensor (ThOR) Defective / Poor Connection

Mitsubishi Electric · Mitsubishi FR-D700 Inverter

What does E37 mean?

The outdoor unit heat exchanger sensor (ThOR) is defective (open circuit resistance) or has a poor connection on the outdoor unit PCB. This error may also specify which particular thermistor (Tho-R1 to Tho-R6) has failed, leading to inaccurate temperature readings.

Additional Steps

Steps 1–2 are listed in Priority Fix.

  1. 3

    If a specific sub-code (E37-1 to E37-6) is indicated, identify and test the corresponding thermistor (Tho-R1 to Tho-R6) directly.

Source: Mitsubishi FR-D700 Inverter
Open Manual (Page 4)