Bosch Mini Split F6 Error Code
Check your model first
- Bosch Climate 5000 Gen 2 / legacy single-zone (Table 12, TIMER lit)
- 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
F6 means an indoor coil outlet temperature sensor error on Bosch Climate 5000 Gen 2 / legacy single-zone systems - the T2B evaporator coil outlet thermistor circuit is open, shorted, or reading outside its allowed window, so the control stops the system. Power cycle once; if F6 returns, the sensor circuit needs technician service.
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 F6 means
F6 means an indoor coil outlet temperature sensor error on Bosch Climate 5000 Gen 2 / legacy single-zone systems - the T2B evaporator coil outlet thermistor circuit is open, shorted, or reading outside its allowed window, so the control stops the system. Power cycle once; if F6 returns, the sensor circuit needs technician service.
Code meaning varies by series
- Bosch Climate 5000 Gen 2 / legacy single-zone (Table 12, TIMER lit): F6 = indoor coil outlet temperature sensor error (T2B, open circuit or short circuit)
- Bosch multi-zone outdoor board: T2B sensor faults display as EC 56 / F1-F6 per head on the multi-zone set
First checks before service
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. 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
Bosch E1 · Bosch E3 · Bosch E4 · Bosch F0 · Bosch F6 · Bosch P3 · Bosch P4 · Bosch P5
Sources
- Bosch Climate 5000 Series Ductless Air Conditioner / Heat Pump Service Manual (official Bosch PDF; Error Codes Tables 12-14, Section 8 Diagnosis & Solution) — verified 2026-08-29
- SplitAtlas Bosch / Climate 5000 A/B legacy R-410A F6 page (AI-generated aggregator - secondary variant only) — verified 2026-08-29
- Heat Pump Answers - Bosch mini split error codes (Gen 2 / Gen 3 / multi-zone tables) — verified 2026-08-29
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