E5 Moderate Moderate DIY

MrCool Mini-Split E5 — Indoor Coil Sensor (T2) Fault

MrCool Mini-Split · Error code E5

What E5 Means

E5 means the indoor evaporator coil temperature sensor (T2 thermistor) is open or shorted, so the unit can't read coil temperature for freeze protection and mode control.

Symptoms

  • Unit stops or won't heat/cool properly
  • E5 on the display

Common Causes

1
Failed T2 coil thermistor

The evaporator coil sensor has failed.

2
Loose sensor connector

The T2 plug on the indoor board is loose.

How to Fix It

  1. Power off and open the indoor unit.
  2. Find the T2 sensor clipped to the evaporator coil and reseat its connector.
  3. Test/replace the thermistor if it reads out of range.

Parts You May Need

If diagnosis points to a failed part, these are the common replacements. As an Amazon Associate we earn from qualifying purchases.

Common replacement Mini-Split Thermistor Sensor Kit View on Amazon→

More MrCool Mini-Split Codes

E1 E1 — Indoor/Outdoor Communication Error E2 E2 — Zero-Crossing Detection Error E3 E3 — Indoor Fan Speed Out of Control E4 E4 — Indoor Room Sensor (T1) Fault F0 F0 — Overload / Current Protection F1 F1 — Outdoor Ambient Sensor (T4) Fault

All MrCool codes → All mini-split codes →

Always unplug an appliance before servicing it. This guide is for informational purposes and is not a substitute for a qualified technician.