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Bosch Mini-Split Error Codes and Troubleshooting 2026 Guide

by Dua Jones April 27, 2026

Bosch mini-splits display fault codes through alphanumeric codes on the indoor unit display or via LED blink patterns on indicator-only models. Bosch's ductless lineup in North America is manufactured by Midea under licence — error codes and fault logic closely follow Midea's platform conventions. This guide covers the most common Bosch mini-split error codes and recommended first steps for each.

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Common Bosch Mini-Split Error Codes

Error Code	Meaning	DIY Fix?	First Step
E1	High pressure protection	Partially	Clear outdoor unit airflow; reset breaker
E2	Low pressure protection / refrigerant issue	No	Call technician — refrigerant leak check
E3	Outdoor fan motor fault	Partially	Check for debris around outdoor unit; call tech
E4	Compressor overload / overheating	Partially	Clear outdoor unit; reset; call tech if recurring
E6	Communication error (indoor to outdoor)	Partially	Reset breaker; inspect signal wire connections
F1	Indoor intake temperature sensor fault	No	Reset; call tech if recurring — thermistor
F2	Indoor coil temperature sensor fault	No	Call technician — thermistor replacement
F3	Outdoor temperature sensor fault	No	Reset; call tech if recurring
P1	Freeze protection — indoor coil too cold	Yes	Clean filter; let coil thaw 2–3 hrs; restart
P2	Drain fault / condensate blockage	Yes	Clear the condensate drain line

How to Read Bosch Blink Codes

On Bosch models with an LED indicator (no display panel), count the number of flashes in each repeating sequence before the pause. The flash count corresponds to the error number (e.g., 3 flashes = E3). Some Bosch models use both an operation LED and a timer LED in combination — count each separately and reference the code combination in your model's service manual.

Always record the exact code before performing a breaker reset — once reset, the code clears from memory and cannot be retrieved without the fault recurring.

Frequently Asked Questions

Where can I find the complete error code list for my Bosch mini-split?

The complete error code list for your specific model is in the Installation and Service Manual, downloadable from Bosch's HVAC product support site using your model number. Bosch's ductless documentation is available at boschheatingandcooling.com. Because Bosch's ductless lineup is manufactured by Midea, some codes may also appear in Midea documentation under the same alphanumeric designations.

My Bosch mini-split shows P1 repeatedly — is it a refrigerant problem?

P1 (freeze protection) is most commonly caused by a dirty filter restricting airflow — not a refrigerant issue. Clean the filter thoroughly, let the unit sit off for 2 hours to let any ice melt, and restart. If P1 returns after cleaning, reduced airflow from a failing fan motor or low refrigerant charge are the next possibilities to investigate with a technician.