Error Code Troubleshooting (Odu) - Bosch 15 SEER2 Series Installation Instructions Manual

Installation Instructions

13.10 Error Code Troubleshooting (ODU)

Error Code Description (Sensor)
P1 High pressure switch (HPS) protection
P5 Condenser coil temperature (T3) protection in cooling
P3 Compressor over current protection
Table 23
P1 (High pressure switch (HPS) protection)
Diagnosis
Check whether the high
pressure switch wires
are seated normally
Yes
Check whether high pressure
switch is closed
Yes
Check whether indoor and
outdoor units are normal by
filter and airflow
Yes
Cooling mode refers to P5
Heating mode refers to Hb
Figure 34
3 4 |
Handling
No
Reseat the wires according
to wiring diagram
No
Replace high pressure switch
No Exclude all fault reasons
and restart
Bosch 15 SEER2 Inverter Ducted Packaged Heat Pump - BTC 761701319 A (12.2022)
P5 (Condenser coil temperature (T3) protection in cooling)
Diagnosis
Check whether T3 is normal
according to Table 36 (between
temperature and resistance)
Yes
Check whether outdoor unit
motor is abnormal or whether
the outdoor condenser coil is
blocked
No
Check whether there is short
circuit in air outlet and inlet side
No
Check whether the charge is
correct by subcooling
according to installation guide
in charge mode when cooling
Yes
Check whether there is
normal throttle
Yes
Figure 35
P3 (Compressor over current protection)
Diagnosis
Check whether outdoor unit
motor is abnormal and the
outdoor condenser coil is
blocked
No
Check whether compressor
wiring is normal
Yes
Check whether compressor
insulation resistance is greater
than 100KΩ
Yes
Restart system and check whether
the difference of high and low
pressure is more than 30 PSI after
compressor has run for 10 mins
Yes
Check whether the
compressor current is more
than 18A when protection
Yes
Figure 36
Handling
No
Replace the T3 sensor
Replace the fan or
Yes
remove all the blockage
Yes
Do something to avoid air
return short circuit
No
Adjust refrigerant charge
No Adjust or repair the EEV
throttle
Handling
Replace the fan or
Yes
remove all the barriers
No
Wire correctly according to
the wiring diagram
No
Replace the compressor
No
Replac e the compressor
No
Replace the board
Replace the compressor