All fault codes

Bosch Compress fault codes

What each code means, from Bosch Compress's own service literature, and which UK models it applies to.

Bosch Compress heat pumps

A01-811DHW: thermal disinfection unsuccessful51 models A11-1000System configuration not confirmed51 models A11-1010No communication via BUS interface EMS 251 models A11-1037Outside temperature sensor: heating standby mode active51 models A11-1038Invalid time/date51 models A11-3061…3064No communication with mixer module (3061 = heating circuit 1 … 3064 = heating circuit 4)51 models A11-3091…3094Room temperature sensor defective (3091 = heating circuit 1 … 3094 = heating circuit 4)51 models A11-6004No communication with solar module51 models A31…A34-3021…3024Heating circuit 1…4 flow temperature sensor faulty: standby mode active51 models A51-6021Solar collector temperature sensor defective51 models A51-6022Cylinder 1 bottom temperature sensor faulty: heating standby mode active51 models A61…A64-1081…1084Two master control units in the system (A61/1081 = heating circuit 1 … A64/1084 = heating circuit 4)51 models A01-5378Outdoor unit defrost failure51 models A01-5522Wrong combination of indoor and outdoor units51 models H01-5594Air in the system51 models H01-5239DHW temperature sensor TW1 fault51 models C0Multiple units configured as master in the master–slave network37 models E0Flow switch error (E8 displayed 3 times; to be seen together with E8)37 models E1Phase sequence error (three-phase units only)37 models E2Communication error between user interface and main hydraulic module control board37 models E3Backup heater's heat exchanger outlet T1 temperature sensor error37 models E4T5 DHW temperature sensor error37 models E5Finned coil outlet T3 refrigerant temperature sensor error (cooling mode)37 models E6T4 room temperature sensor error37 models E7Tbt1 sensor error37 models E8Water flow-rate error37 models E9Th suction pipe sensor error37 models EATp discharge temperature sensor error37 models EbSolar panel sensor error (Tsolar)37 models EdTw_in entering water temperature sensor error37 models EEEEPROM failure, main hydraulic module control board37 models bHPED board error37 models H0Communication error: main PCB B ↔ main hydraulic module control board37 models H1Communication error: PCB A inverter module ↔ main PCB B37 models H2Plate heat exchanger inlet temperature sensor (T2), refrigerant side, cooling mode37 models H3Heat exchanger outlet temperature sensor (T2B), refrigerant side, cooling mode37 models H4Three P6 protection activations37 models H5Ta internal temperature sensor error37 models H6DC fan error37 models H7Main circuit voltage fault37 models H8Pressure sensor error37 models H9Tw2 sensor error37 models HATW_out leaving water temperature sensor (plate heat exchanger)37 models HbPP protection trips 3 times and Tw_out < 7 °C37 models HdCommunication error between master and slave units37 models HECommunication error between main board and thermostat37 models HFInverter module EEprom error37 models HHH6 displayed 10 times in 2 hours37 models HLPFC module fault37 models HPLow pressure protection (Pe < 0.6) tripped 3 times in one hour37 models P0Low pressure protection37 models P1High pressure protection37 models P3Compressor overcurrent protection37 models P4Protection for high discharge temperature37 models P5Protection: high ΔT between entering and leaving water (plate heat exchanger)37 models

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