Bosch BRBA-36HWD1N1-M18 - Page 33

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Installation Instructions
Bosch 18 SEER2 Series Inverter Ducted Packaged Heat Pump - BTC 761703103 A (11.2022)
Error Code Description
E9 EEPROM fault
H0 Communication fault in main control chip
E5 High/low voltage protection
Table 28
If error codes E9/H0/E5 appear occasionally and after the system restarts and
runs normally after the power supply is re-established, no action is necessary.
Otherwise the system must be checked.
Figure 46
E9 (EEPROM fault)
Diagnosis Handling
Check whether the wiring is
connected normally
Yes
Restart to power on and
check whether it is normal
Reseat the wiring according
to wiring diagram
No
Reseat the wiring according
to wiring diagram
Replace the control board
Yes
The fault is
still present
No action is necessary. This fault
may be caused by strong
interference from the electric grid.
The system will recover when the
electric supply stabilizes.
No
Figure 47
H0 (Communication fault in main control chip)
Diagnosis
Handling
Yes
No action is necessary. This fault may
be caused by strong interference from
the electric grid. The system will
recover when the electric supply
stabilizes.
No
No
Yes
No
Check whether the wiring is
connected normally
Reseat the wiring according
to wiring diagram
Restart to power on and
check whether it is normal
Replace the control board
Replace the control board
Figure 48
E5 (High/low voltage protection)
Diagnosis
Handling
Yes
Check whether the power wires are
connected firmly and whether the
power supply wires diameter meets
the requirements from the
manufacturer
Yes
Restart to the power supply
and check whether the
compressor operates normally
Yes
Check whether there is
high voltage equipment
nearby
Yes
No
No
Replace the power supply
wires or connect the power
supply wires well
No
Replace the control board
No
Yes
Separate high-power
equipment and power
supply
No
Check whether the power
supply voltage is between
172-270V
Make sure the power
supply is within correct
range
Gauge and check whether
there is 380V DC between the
terminals P & N when the
compressor is running
Replace the control board