Bosch Mini Split F3 Error Code

Updated 2026-08-30 · review status: manual-verified · reviewed by MiniSplitDecoder Editorial Team Last verified: 2026-08-30

Check your model first

  • Bosch Climate 5000 Gen 2 / legacy single-zone (BMS500-A..)
  • Bosch multi-zone (variant meaning)
  • Bosch Climate 5000 Gen 2 / legacy single-zone
  • Bosch multi-zone outdoor board

Match the model on your equipment label to the linked manufacturer documentation. The same code can mean different things across model families.

Quick answer

F3 on a Bosch Climate 5000 Gen 2 single-zone system means a compressor discharge temperature sensor error - the discharge (T5/Tp) thermistor is open, shorted, or drifted. One power-cycle reset is the safe DIY step; sensor and sealed-system checks are technician work.

Severity: medium · DIY difficulty: easy

Safety

Stop at the breaker power-cycle and any plug-accessible checks (filters, remote settings, visible wiring). The outdoor unit's capacitor holds a lethal charge and the refrigerant circuit is both pressurized and (on R-32 units) flammable — opening panels or servicing the sealed system is licensed-technician work (EPA 608).

What F3 means

F3 means a compressor discharge temperature sensor error on Bosch Climate 5000 Gen 2 / legacy single-zone systems (indoor lamp group: 4 lit) - the discharge thermistor is open circuit or short circuited, the signature of a broken wire, a disconnected plug, or a failed thermistor per Heat Pump Answers. Gen 3 equivalent is EC 54. On a multi-zone outdoor board, F3 instead names indoor head C as the room with a failed sensor.

Code meaning varies by series

  • Bosch Climate 5000 Gen 2 / legacy single-zone: Compressor discharge temperature sensor error (indoor LED: 4 lit; Gen 3 equivalent EC 54, TP/T5 discharge sensor)
  • Bosch multi-zone outdoor board: On a Bosch multi-zone outdoor board the F1-F6 range instead names which indoor head (A-F) has a failed sensor, not the fault type - say which display you read the code on. F3 = indoor unit C

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.

Related codes

Cross-references for the same fault family, by brand:

Bosch F1 · Bosch F2

Commonly searched as: "bosch f3" · "bosch error code f3" · "bosch air conditioner f3"

Sources

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