Bosch 15 SEER2 Series Installation Instructions Manual page 38

Installation Instructions
Error Code Description
E9 EEPROM fault
H0 Communication fault in main control chip
E5 High/low voltage protection
E1 Communication error
Table 30
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.
E9 (EEPROM fault)
Diagnosis
Check whether the wiring is
connected normally
Yes
Restart to power on and
check whether it is normal
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.
Figure 48
H0 (Communication fault in main control chip)
Diagnosis
Check whether the wiring is
connected normally
Yes
Restart to power on and
check whether it is normal
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.
Figure 49
3 8 |
Handling
No
Reseat the wiring according
to wiring diagram
No
Reseat the wiring according
to wiring diagram
The fault is
still present
Replace the control board
Handling
No
Reseat the wiring according
to wiring diagram
No
Replace the control board
No
Replace the control board
Bosch 15 SEER2 Inverter Ducted Packaged Heat Pump - BTC 761701319 A (12.2022)
E5 (High/low voltage protection)
Diagnosis
Check whether the power
supply voltage is between
172-270V
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
Gauge and check whether
there is 380V DC between the
terminals P & N when the
compressor is running
Yes
Check whether there is
high voltage equipment
nearby
No
Figure 50
E1 (Communication error)
Diagnosis
Check whether the wiring is
connected normally
Yes
Restart to power on and
check whether it is normal
Yes
You need do nothing. Perhaps this
fault is caused by accident, such as
strong interference form electricity
grid. System will recovery when
electricity grid is normal
Figure 51
Handling
Make sure the power
No
supply is within correct
range
Replace the power supply
No
wires or connect the power
supply wires well
No
Replace the control board
No
Replace the control board
Separate high-power
Yes
equipment and power
supply
Handling
No
Reseat the wiring according
to wiring diagram
No
Replace the control board
of the indoor unit
The fault is still
Replace the control board
of the outdoor unit