Bosch 15 SEER2 Series - P2 (Low pressure (PT) Protection in cooling); P4 (High compressor discharge temperature (T5) protection)

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Installation Instructions
Bosch 15 SEER2 Inverter Ducted Packaged Heat Pump - BTC 761701319 A (12.2022)
Error Code Description
PH Low discharge super heat protection
P0 High module radiator temperature (TF) protection
Table 24
Figure 37
Figure 38
P0 (High module radiator temperature (TF) protection)
Diagnosis Handling
Check whether there is
dust or fallen leaves
influencing the radiator
No
Check whether the Tf is
normal according to Table
37 (between temperature
and resistance)
Yes
Clean all the dust
and fallen leaves
Yes
Replace Tf sensor
or Control Board
Restart system and check
whether the fan and motor
can operate normally
Replace the fan and motor
No
No
Yes
Operate system and check
whether there`s the same fault
Operate normally
No
Yes
Error Code Description
P2 Low pressure (PT) Protection in cooling and heating
H5
System lockup, 5 times (P2) protection in 100
minutes
P4 High compressor discharge temperature(T5)
Table 25
Figure 39
P2 (Low pressure (PT) Protection in cooling)
H5 (System lockup, 5 times (P2) protection in 100 minutes)
Diagnosis Handling
Check whether indoor unit is
normal by valve, filter, airflow
and throttle.
Yes
Yes
Check whether the pressure
transduce is measuring
properly from the 8th or 11th
data of check when cooling.
Exclude indoor unit
fault reasons and
restart
No
Adjust the charge
No
Replace the pressure
transducer
No
Yes
Check whether the charge is
correct by subcooling
according to installation guide
in charge mode when cooling.
Figure 40
P4 (High compressor discharge temperature (T5) protection)
Diagnosis Handling
Yes
Check whether the charge is
correct by subcooling
according to installation guide
in charge mode when cooling
No
Check whether the
compressor is normal
(abnormal noise,abnormal
vibration)
Yes
Check whether the EEV is
normal for throttle when
heating (wire seated .coil)
Adjust the charge
Yes
Replace the compressor
No
Re-power and check
again,if the same, replace
the EEV.
No
Yes
Check whether the T5 is normal
according to Table 37 (between
temperature and resistance)
Replace the T5 sensor
No