Rinnai
31
Commercial Heat Pump OIM
ALARM CODES & TROUBLESHOOTING
Code
Description
Troubleshooting
A05
Tank water temperature
probe - failure
•
Ensure tank sensor connect to terminal “1&2”.
•
Check tank sensor if broken (NTC thermistor: 10KΩ@25°C).
A06
Outlet water temperature
probe - failure
•
Check outlet water temp sensor connection. Refer to electric diagram
located on the back of access door.
•
Check temp sensor if broken (NTC thermistor: 10KΩ@25°C).
A13
User pump maintenance
Remind user to check component operation status. Call your installer to
book maintenance. This alarm doesn’t affect your heat pump operation.
A16
Ambient temperature probe
- failure
•
Check ambient temp sensor connection. Refer to electric diagram located
on the back of access door.
•
Check temp sensor if broken (NTC thermistor: 10KΩ@25°C).
A24
Suction temperature probe
- failure
•
Check suction temp sensor connection. Refer to electric diagram located
on the back of access door.
•
Check temp sensor if broken (NTC thermistor: 10KΩ@25°C)
A25
High pressure switch open
•
Check if stop valves open and hot water loop is filled with water. After fix
the issues, switch off/on the unit to restart.
•
Check if tank sensor is installed in tank thermostat well.
•
Check if all breakers have switched on in electric enclosure.
•
Check high pressure switch connection. Refer to electric diagram located
on the back of access door (marked as HP).
•
Check pressure switch if broken (NC type: normal close).
A26
High pressure transducer
exceeds threshold or failure
•
Check if stop valves open and hot water loop is filled with water. After fix
the issues, switch off/on the unit to restart.
•
Check if tank sensor is installed in tank thermostat well.
•
Check if all breakers have switched on in electric enclosure.
•
Check high pressure transducer connection. Refer to electric diagram
located on the back of access door (marked as condensing pressure).
•
Check pressure transducer if broken.
A27
Low pressure transducer -
failure
•
Check if fan airflow was blocked due to obstacles or dirty coil. After fix the
issue, switch off/on the unit to restart.
•
Check if all breakers have switched on in electric enclosure.
•
Check if fan and electronic expansion valve work.
•
Check if refrigerant escaped and leakage spots.
•
Check low pressure transducer connection. Refer to electric diagram
located on the back of access door (marked as evaporating pressure).
•
Check pressure transducer if broken.
A29
Low pressure switch open
•
Check if fan airflow was blocked due to obstacles or dirty coil. After fix the
issue, switch off/on the unit to restart.
•
Check if all breakers have switched on in electric enclosure.
•
Check if fan and electronic expansion valve work.
•
Check if refrigerant escaped and leakage spots.
•
Check low pressure switch connection. Refer to electric diagram located on
the back of access door (marked as LP).
•
Check pressure switch if broken (NC type: normal close when refrigerant
exists in the system).
A30
Reversed phase of power
supply or compressor
overload
•
Check 3 phase order from isolating switch to heat pump
•
Check current setting on compressor overload. Refer to electric diagram
located on the back of access door.
•
Check 3 phase fail relay if broken.
•
Check compressor overload if broken.
A32
Compressor maintenance
Remind user to check component operation status. Call your installer to
book maintenance. This alarm doesn’t affect your heat pump operation.
A34
Fan maintenance
Remind user to check component operation status. Call your installer to
book maintenance. This alarm doesn’t affect your heat pump operation.
CHECKLIST
