Bosch Mini Split E5 Error Code

What E5 means

E5 means an indoor coil temperature sensor error on Bosch Climate 5000 Gen 2 / legacy single-zone systems - the evaporator (T2) thermistor is open, shorted, or reading outside its allowed window, so the control stops the system. On multi-zone Bosch outdoor boards E5 instead means over-voltage or under-voltage protection; confirm which display you are reading.

First checks before service

This page currently documents the safe reset triage. If the code returns, use the linked source manual or a qualified technician for code-specific diagnosis.

1. 1. One-time fault event (power disturbance or transient sensor reading) common DIY

   Check: Power-cycle at the breaker/disconnect (or unplug for CPAP), restore, and run the system while watching for the code.

   Fix: If the code does not return after a full run cycle, the fault was transient — monitor, no repair needed.

2. 2. Fault persists after a clean reset occasional pro only

   Check: If the code returns immediately or every session, note the conditions (startup, heating, after rain).

   Fix: A persisting code points at the component the manual assigns to this code — that repair is technician territory.