What does your Rinnai fault code mean?
Pick the code showing on your remote, wall controller or indoor unit and see what it means, what commonly causes it, and what is safe to check yourself. This page covers 64 Rinnai fault codes for units sold in Australia, compiled from official Australian manufacturer and distributor documentation, the same references our own technicians carry.
Heads up: Rinnai uses the same code with different meanings on different product ranges, so check the model range shown next to the code.
Every Rinnai fault code at a glance
Some models show faults as a flashing-light pattern instead of a code; documented lamp patterns are listed alongside their codes.
| Code | What it means | Severity |
|---|---|---|
| E0 (Q series inverter wall-mounted splits (HSNRQ25B, HSNRQ35B, HSNRQ50B, HSNRQ70B, HSNRQ80B systems; HINRQ indoor, HONRQ outdoor)) | The indoor unit has shut down because it detected the system drawing more electrical current than is safe. | Fault – service needed |
| E0 (Inverter slim four-way cassette systems (CIN070R, CIN100R, CIN120R, CIN140R indoor with DONSR series outdoor)) | The indoor unit’s memory chip (EEPROM) has failed, so the unit cannot read its stored settings. | Fault – service needed |
| E1 (Q series inverter wall-mounted splits (HSNRQ25B, HSNRQ35B, HSNRQ50B, HSNRQ70B, HSNRQ80B systems; HINRQ indoor, HONRQ outdoor)) | The indoor room temperature sensor has failed or lost connection. | Minor fault |
| E1 (Inverter slim four-way cassette systems (CIN070R, CIN100R, CIN120R, CIN140R indoor with DONSR series outdoor)) | The indoor and outdoor units have lost communication with each other. | Fault – service needed |
| E2 (Q series inverter wall-mounted splits (HSNRQ25B, HSNRQ35B, HSNRQ50B, HSNRQ70B, HSNRQ80B systems; HINRQ indoor, HONRQ outdoor)) | The outdoor coil temperature sensor has failed or lost connection. | Minor fault |
| E3 (Q series inverter wall-mounted splits (HSNRQ25B, HSNRQ35B, HSNRQ50B, HSNRQ70B, HSNRQ80B systems; HINRQ indoor, HONRQ outdoor)) | The indoor coil temperature sensor has failed or lost connection. | Minor fault |
| E3 (Inverter slim four-way cassette systems (CIN070R, CIN100R, CIN120R, CIN140R indoor with DONSR series outdoor)) | The indoor fan is not running at the speed the control board expects. | Fault – service needed |
| E4 (Q series inverter wall-mounted splits (HSNRQ25B, HSNRQ35B, HSNRQ50B, HSNRQ70B, HSNRQ80B systems; HINRQ indoor, HONRQ outdoor)) | The indoor fan motor is not running properly or its speed signal is not reaching the control board. | Fault – service needed |
| E4 (Inverter slim four-way cassette systems (CIN070R, CIN100R, CIN120R, CIN140R indoor with DONSR series outdoor)) | The indoor room temperature sensor has failed or lost connection. | Minor fault |
| E5 (Q series inverter wall-mounted splits (HSNRQ25B, HSNRQ35B, HSNRQ50B, HSNRQ70B, HSNRQ80B systems; HINRQ indoor, HONRQ outdoor)) also shown as 5E |
The indoor and outdoor units have lost communication with each other. | Fault – service needed |
| E5 (Inverter slim four-way cassette systems (CIN070R, CIN100R, CIN120R, CIN140R indoor with DONSR series outdoor)) | The evaporator coil temperature sensor has failed or lost connection. | Minor fault |
| E8 (Inverter slim four-way cassette systems (CIN070R, CIN100R, CIN120R, CIN140R indoor with DONSR series outdoor), twin models only) | The two indoor units of a twin system have lost communication with each other. | Fault – service needed |
| E9 (Inverter slim four-way cassette systems (CIN070R, CIN100R, CIN120R, CIN140R indoor with DONSR series outdoor), twin models only) | A fault has occurred in the twin indoor unit configuration. | Fault – service needed |
| EC (Inverter slim four-way cassette systems (CIN070R, CIN100R, CIN120R, CIN140R indoor with DONSR series outdoor)) | The system has detected a possible refrigerant leak or a fault in its refrigerant leak detection system. | Urgent – turn it off |
| EE (Inverter slim four-way cassette systems (CIN070R, CIN100R, CIN120R, CIN140R indoor with DONSR series outdoor)) | The condensate water level alarm has triggered or its float switch has failed, meaning drain water may not be clearing. | Fault – service needed |
| Eb (Q series inverter wall-mounted splits (HSNRQ25B, HSNRQ35B, HSNRQ50B, HSNRQ70B, HSNRQ80B systems; HINRQ indoor, HONRQ outdoor)) | The indoor unit’s memory chip (EEPROM) cannot be read, so the unit cannot load its settings. | Fault – service needed |
| F0 (Q series inverter wall-mounted splits (HSNRQ25B, HSNRQ35B, HSNRQ50B, HSNRQ70B, HSNRQ80B systems; HINRQ indoor, HONRQ outdoor)) | The outdoor fan motor is not running properly. | Fault – service needed |
| F0 (Inverter slim four-way cassette systems (CIN070R, CIN100R, CIN120R, CIN140R indoor with DONSR series outdoor)) | The system has shut down to protect itself from working under overload. | Fault – service needed |
| F1 (Q series inverter wall-mounted splits (HSNRQ25B, HSNRQ35B, HSNRQ50B, HSNRQ70B, HSNRQ80B systems; HINRQ indoor, HONRQ outdoor)) | The power module driving the compressor has shut the system down to protect itself. | Fault – service needed |
| F1 (Inverter slim four-way cassette systems (CIN070R, CIN100R, CIN120R, CIN140R indoor with DONSR series outdoor)) | The outdoor air temperature sensor has failed or lost connection. | Minor fault |
| F2 (Q series inverter wall-mounted splits (HSNRQ25B, HSNRQ35B, HSNRQ50B, HSNRQ70B, HSNRQ80B systems; HINRQ indoor, HONRQ outdoor)) | The power factor correction (PFC) board has detected an electrical fault and shut the system down. | Fault – service needed |
| F2 (Inverter slim four-way cassette systems (CIN070R, CIN100R, CIN120R, CIN140R indoor with DONSR series outdoor)) | The outdoor condenser pipe temperature sensor has failed or lost connection. | Minor fault |
| F3 (Q series inverter wall-mounted splits (HSNRQ25B, HSNRQ35B, HSNRQ50B, HSNRQ70B, HSNRQ80B systems; HINRQ indoor, HONRQ outdoor)) | The compressor failed to start or lost its normal rhythm while running. | Fault – service needed |
| F3 (Inverter slim four-way cassette systems (CIN070R, CIN100R, CIN120R, CIN140R indoor with DONSR series outdoor)) | The compressor discharge air temperature sensor has failed or lost connection. | Minor fault |
| F4 (Q series inverter wall-mounted splits (HSNRQ25B, HSNRQ35B, HSNRQ50B, HSNRQ70B, HSNRQ80B systems; HINRQ indoor, HONRQ outdoor)) | The compressor discharge (exhaust) temperature sensor has failed or lost connection. | Minor fault |
| F4 (Inverter slim four-way cassette systems (CIN070R, CIN100R, CIN120R, CIN140R indoor with DONSR series outdoor)) | The outdoor unit’s memory chip (EEPROM) has failed, so the unit cannot read its stored settings. | Fault – service needed |
| F5 (Q series inverter wall-mounted splits (HSNRQ25B, HSNRQ35B, HSNRQ50B, HSNRQ70B, HSNRQ80B systems; HINRQ indoor, HONRQ outdoor)) | The compressor’s overheat protection switch has opened, usually because the compressor got too hot. | Fault – service needed |
| F5 (Inverter slim four-way cassette systems (CIN070R, CIN100R, CIN120R, CIN140R indoor with DONSR series outdoor)) | The outdoor fan is not running at the speed the control board expects. | Fault – service needed |
| F6 (Q series inverter wall-mounted splits (HSNRQ25B, HSNRQ35B, HSNRQ50B, HSNRQ70B, HSNRQ80B systems; HINRQ indoor, HONRQ outdoor)) | The outdoor air temperature sensor has failed or lost connection. | Minor fault |
| F6 (Inverter slim four-way cassette systems (CIN070R, CIN100R, CIN120R, CIN140R indoor with DONSR series outdoor)) | The T2b coil outlet temperature sensor has failed or lost connection. | Minor fault |
| F7 (Q series inverter wall-mounted splits (HSNRQ25B, HSNRQ35B, HSNRQ50B, HSNRQ70B, HSNRQ80B systems; HINRQ indoor, HONRQ outdoor)) | The power supply voltage is outside the safe operating range, so the unit has shut down to protect itself. | Fault – service needed |
| F7 (Inverter slim four-way cassette systems (CIN070R, CIN100R, CIN120R, CIN140R indoor with DONSR series outdoor), auto-lifting panel models only) | The auto-lifting panel has lost communication with the unit. | Minor fault |
| F8 (Q series inverter wall-mounted splits (HSNRQ25B, HSNRQ35B, HSNRQ50B, HSNRQ70B, HSNRQ80B systems; HINRQ indoor, HONRQ outdoor)) | The outdoor unit’s main board and its inverter module board have lost communication. | Fault – service needed |
| F8 (Inverter slim four-way cassette systems (CIN070R, CIN100R, CIN120R, CIN140R indoor with DONSR series outdoor), auto-lifting panel models only) | The auto-lifting panel mechanism has a fault. | Minor fault |
| F9 (Q series inverter wall-mounted splits (HSNRQ25B, HSNRQ35B, HSNRQ50B, HSNRQ70B, HSNRQ80B systems; HINRQ indoor, HONRQ outdoor)) | The outdoor unit’s memory chip (EEPROM) cannot be read, so the unit cannot load its settings. | Fault – service needed |
| F9 (Inverter slim four-way cassette systems (CIN070R, CIN100R, CIN120R, CIN140R indoor with DONSR series outdoor), auto-lifting panel models only) | The auto-lifting panel is open and has not returned to its closed position. | Minor fault |
| FA (Q series inverter wall-mounted splits (HSNRQ25B, HSNRQ35B, HSNRQ50B, HSNRQ70B, HSNRQ80B systems; HINRQ indoor, HONRQ outdoor)) | The refrigerant return temperature sensor has failed, or the four-way valve is not switching properly. | Minor fault |
| L0 (Q series inverter wall-mounted splits (HSNRQ25B, HSNRQ35B, HSNRQ50B, HSNRQ70B, HSNRQ80B systems; HINRQ indoor, HONRQ outdoor)) | The outdoor unit’s internal DC voltage went outside safe limits, so the system shut down. This is a subdivided version of the F1 module protection fault. | Fault – service needed |
| L1 (Q series inverter wall-mounted splits (HSNRQ25B, HSNRQ35B, HSNRQ50B, HSNRQ70B, HSNRQ80B systems; HINRQ indoor, HONRQ outdoor)) | The compressor drew more current through one of its windings than is safe, so the system shut down. This is a subdivided version of the F1 module protection fault. | Fault – service needed |
| L2 (Q series inverter wall-mounted splits (HSNRQ25B, HSNRQ35B, HSNRQ50B, HSNRQ70B, HSNRQ80B systems; HINRQ indoor, HONRQ outdoor)) | The compressor lost its normal running rhythm (out of step), so the system shut down. This is a subdivided version of the F1 module protection fault. | Fault – service needed |
| L3 (Q series inverter wall-mounted splits (HSNRQ25B, HSNRQ35B, HSNRQ50B, HSNRQ70B, HSNRQ80B systems; HINRQ indoor, HONRQ outdoor)) | One of the compressor’s electrical phases is missing or not connected, so the system shut down. This is a subdivided version of the F1 module protection fault. | Fault – service needed |
| L4 (Q series inverter wall-mounted splits (HSNRQ25B, HSNRQ35B, HSNRQ50B, HSNRQ70B, HSNRQ80B systems; HINRQ indoor, HONRQ outdoor)) | The power module (IPM) that drives the compressor has failed or shut itself down. This is a subdivided version of the F1 module protection fault. | Fault – service needed |
| L5 (Q series inverter wall-mounted splits (HSNRQ25B, HSNRQ35B, HSNRQ50B, HSNRQ70B, HSNRQ80B systems; HINRQ indoor, HONRQ outdoor)) | The power factor correction (PFC) circuit’s hardware protection detected too much current and shut the system down. This is a subdivided version of the F1 module protection fault. | Fault – service needed |
| L6 (Q series inverter wall-mounted splits (HSNRQ25B, HSNRQ35B, HSNRQ50B, HSNRQ70B, HSNRQ80B systems; HINRQ indoor, HONRQ outdoor)) | The power factor correction (PFC) circuit’s software protection detected too much current and shut the system down. This is a subdivided version of the F1 module protection fault. | Fault – service needed |
| L7 (Q series inverter wall-mounted splits (HSNRQ25B, HSNRQ35B, HSNRQ50B, HSNRQ70B, HSNRQ80B systems; HINRQ indoor, HONRQ outdoor)) | The circuit that measures electrical current on the outdoor controller is giving abnormal readings, so the system shut down. This is a subdivided version of the F1 module protection fault. | Fault – service needed |
| L8 (Q series inverter wall-mounted splits (HSNRQ25B, HSNRQ35B, HSNRQ50B, HSNRQ70B, HSNRQ80B systems; HINRQ indoor, HONRQ outdoor)) | The outdoor controller’s current-sensing components are out of balance, so the system shut down. This is a subdivided version of the F1 module protection fault. | Fault – service needed |
| L9 (Q series inverter wall-mounted splits (HSNRQ25B, HSNRQ35B, HSNRQ50B, HSNRQ70B, HSNRQ80B systems; HINRQ indoor, HONRQ outdoor)) | The temperature sensor on the outdoor unit’s inverter power module (IPM) has failed. This is a subdivided version of the F1 module protection fault. | Minor fault |
| LA (Q series inverter wall-mounted splits (HSNRQ25B, HSNRQ35B, HSNRQ50B, HSNRQ70B, HSNRQ80B systems; HINRQ indoor, HONRQ outdoor)) | The compressor failed to start. This is a subdivided version of the F1 module protection fault. | Fault – service needed |
| LC (Q series inverter wall-mounted splits (HSNRQ25B, HSNRQ35B, HSNRQ50B, HSNRQ70B, HSNRQ80B systems; HINRQ indoor, HONRQ outdoor)) | The circuit that measures current in the outdoor unit’s power factor correction (PFC) stage is giving abnormal readings, so the system shut down. This is a subdivided version of the F1 module protection fault. | Fault – service needed |
| P0 (Inverter slim four-way cassette systems (CIN070R, CIN100R, CIN120R, CIN140R indoor with DONSR series outdoor)) | The inverter power module has shut the system down to protect itself. | Fault – service needed |
| P1 (Inverter slim four-way cassette systems (CIN070R, CIN100R, CIN120R, CIN140R indoor with DONSR series outdoor)) | The power supply voltage is too high or too low, so the unit has shut down to protect itself. | Fault – service needed |
| P2 (Q series inverter wall-mounted splits (HSNRQ25B, HSNRQ35B, HSNRQ50B, HSNRQ70B, HSNRQ80B systems; HINRQ indoor, HONRQ outdoor)) | The system has shut down because refrigerant pressure climbed too high. | Fault – service needed |
| P2 (Inverter slim four-way cassette systems (CIN070R, CIN100R, CIN120R, CIN140R indoor with DONSR series outdoor)) | The top of the compressor got too hot, so the unit shut down to protect it. | Fault – service needed |
| P3 (Q series inverter wall-mounted splits (HSNRQ25B, HSNRQ35B, HSNRQ50B, HSNRQ70B, HSNRQ80B systems; HINRQ indoor, HONRQ outdoor)) | The system has detected it is very low on refrigerant and has shut down to protect the compressor. | Fault – service needed |
| P3 (Inverter slim four-way cassette systems (CIN070R, CIN100R, CIN120R, CIN140R indoor with DONSR series outdoor)) | The unit has stopped because the outdoor temperature is too low for safe operation. | Minor fault |
| P4 (Q series inverter wall-mounted splits (HSNRQ25B, HSNRQ35B, HSNRQ50B, HSNRQ70B, HSNRQ80B systems; HINRQ indoor, HONRQ outdoor)) | The outdoor coil got too hot in cooling mode, so the unit slowed down or stopped to protect the compressor. | Fault – service needed |
| P4 (Inverter slim four-way cassette systems (CIN070R, CIN100R, CIN120R, CIN140R indoor with DONSR series outdoor)) | The inverter cannot drive the compressor properly. | Fault – service needed |
| P5 (Q series inverter wall-mounted splits (HSNRQ25B, HSNRQ35B, HSNRQ50B, HSNRQ70B, HSNRQ80B systems; HINRQ indoor, HONRQ outdoor)) | The compressor discharge temperature climbed too high, so the unit shut down to protect itself. | Fault – service needed |
| P5 (Inverter slim four-way cassette systems (CIN070R, CIN100R, CIN120R, CIN140R indoor with DONSR series outdoor)) | Indoor units on the same outdoor unit are set to conflicting modes, such as one heating and one cooling. | Minor fault |
| P6 (Q series inverter wall-mounted splits (HSNRQ25B, HSNRQ35B, HSNRQ50B, HSNRQ70B, HSNRQ80B systems; HINRQ indoor, HONRQ outdoor)) | The indoor coil got too hot in heating mode, so the unit stopped to protect itself. | Minor fault |
| P6 (Inverter slim four-way cassette systems (CIN070R, CIN100R, CIN120R, CIN140R indoor with DONSR series outdoor)) | Refrigerant pressure dropped too low, so the unit shut down to protect the compressor. | Fault – service needed |
| P7 (Q series inverter wall-mounted splits (HSNRQ25B, HSNRQ35B, HSNRQ50B, HSNRQ70B, HSNRQ80B systems; HINRQ indoor, HONRQ outdoor)) | The indoor coil got cold enough to start freezing in cooling mode, so the unit stopped to protect itself. | Minor fault |
| P7 (Inverter slim four-way cassette systems (CIN070R, CIN100R, CIN120R, CIN140R indoor with DONSR series outdoor)) | The temperature sensor on the outdoor unit’s inverter power transistor (IGBT) has failed. | Minor fault |
| P8 (Q series inverter wall-mounted splits (HSNRQ25B, HSNRQ35B, HSNRQ50B, HSNRQ70B, HSNRQ80B systems; HINRQ indoor, HONRQ outdoor)) | The unit detected electrical current above its safe limit and reduced power or shut down. | Fault – service needed |
Codes that mean switch the system off
If your Rinnai unit shows EC, turn the system off at the isolator and leave it off. These faults involve the compressor, refrigerant or electrical protection, and running the unit can cause further damage.
The most serious Rinnai fault codes explained
What does Rinnai fault code EC mean? (Inverter slim four-way cassette systems (CIN070R, CIN100R, CIN120R, CIN140R indoor with DONSR series outdoor))
The system has detected a possible refrigerant leak or a fault in its refrigerant leak detection system.
Likely causes:
- Refrigerant leak in the system
- Leak detection sensor fault
- Indoor circuit board fault
Safe checks before you call:
- Turn the system off at the isolator and stop using it
- Open windows or doors to ventilate the room
- Keep open flames away from the unit until it has been checked
What does Rinnai fault code E0 mean? (Q series inverter wall-mounted splits (HSNRQ25B, HSNRQ35B, HSNRQ50B, HSNRQ70B, HSNRQ80B systems; HINRQ indoor, HONRQ outdoor))
The indoor unit has shut down because it detected the system drawing more electrical current than is safe.
Likely causes:
- Unstable or low mains supply voltage
- System overloaded or airflow blocked
- Current sensor or indoor circuit board fault
- Compressor drawing excessive current
Safe checks before you call:
- Turn the system off at the isolator or breaker for 5 minutes, then restart
- Clean the return air filters if they are dirty
- Check whether lights flicker or other appliances are playing up, which can point to a supply problem
What does Rinnai fault code E4 mean? (Q series inverter wall-mounted splits (HSNRQ25B, HSNRQ35B, HSNRQ50B, HSNRQ70B, HSNRQ80B systems; HINRQ indoor, HONRQ outdoor))
The indoor fan motor is not running properly or its speed signal is not reaching the control board.
Likely causes:
- Fan jammed or obstructed
- Indoor fan motor failure
- Speed feedback circuit fault
- Indoor circuit board fault
Safe checks before you call:
- Turn the system off at the isolator or breaker for 5 minutes, then restart
- Listen and look for the indoor fan spinning after restart, without opening any covers
What does Rinnai fault code E5 mean? (Q series inverter wall-mounted splits (HSNRQ25B, HSNRQ35B, HSNRQ50B, HSNRQ70B, HSNRQ80B systems; HINRQ indoor, HONRQ outdoor))
The indoor and outdoor units have lost communication with each other.
Likely causes:
- Loose or damaged interconnecting cable between indoor and outdoor units
- Indoor or outdoor circuit board fault
- Power supply problem at the outdoor unit
Safe checks before you call:
- Check the outdoor unit isolator switch is on
- Turn the system off at the isolator or breaker for 5 minutes, then restart
What does Rinnai fault code Eb mean? (Q series inverter wall-mounted splits (HSNRQ25B, HSNRQ35B, HSNRQ50B, HSNRQ70B, HSNRQ80B systems; HINRQ indoor, HONRQ outdoor))
The indoor unit’s memory chip (EEPROM) cannot be read, so the unit cannot load its settings.
Likely causes:
- Memory chip poor contact or failure
- Indoor circuit board fault
- Power surge damage
Safe checks before you call:
- Turn the system off at the isolator or breaker for 5 minutes, then restart
What does Rinnai fault code F0 mean? (Q series inverter wall-mounted splits (HSNRQ25B, HSNRQ35B, HSNRQ50B, HSNRQ70B, HSNRQ80B systems; HINRQ indoor, HONRQ outdoor))
The outdoor fan motor is not running properly.
Likely causes:
- Outdoor fan jammed by leaves or debris
- Outdoor DC fan motor failure
- Outdoor circuit board fault
Safe checks before you call:
- Turn the system off at the isolator or breaker for 5 minutes, then restart
- Look for leaves or rubbish caught around the outdoor unit and clear anything you can reach without opening it
What does Rinnai fault code F1 mean? (Q series inverter wall-mounted splits (HSNRQ25B, HSNRQ35B, HSNRQ50B, HSNRQ70B, HSNRQ80B systems; HINRQ indoor, HONRQ outdoor))
The power module driving the compressor has shut the system down to protect itself.
Likely causes:
- Supply voltage too high or too low
- Blocked outdoor coil causing high system pressure
- Compressor or compressor wiring fault
- Power module or outdoor circuit board fault
Safe checks before you call:
- Turn the system off at the isolator or breaker for 5 minutes, then restart
- Check nothing is covering or crowding the outdoor unit
What does Rinnai fault code L0 mean? (Q series inverter wall-mounted splits (HSNRQ25B, HSNRQ35B, HSNRQ50B, HSNRQ70B, HSNRQ80B systems; HINRQ indoor, HONRQ outdoor))
The outdoor unit’s internal DC voltage went outside safe limits, so the system shut down. This is a subdivided version of the F1 module protection fault.
Likely causes:
- Unstable or fluctuating mains supply voltage
- Outdoor unit controller fault
Safe checks before you call:
- Check whether lights flicker or other appliances are playing up, which can point to a supply problem
- Turn the system off at the isolator or breaker for 5 minutes, then restart
What does Rinnai fault code L1 mean? (Q series inverter wall-mounted splits (HSNRQ25B, HSNRQ35B, HSNRQ50B, HSNRQ70B, HSNRQ80B systems; HINRQ indoor, HONRQ outdoor))
The compressor drew more current through one of its windings than is safe, so the system shut down. This is a subdivided version of the F1 module protection fault.
Likely causes:
- Unstable mains supply voltage
- Compressor or compressor wiring fault
- Outdoor unit controller fault
Safe checks before you call:
- Turn the system off at the isolator or breaker for 5 minutes, then restart
- Check nothing is covering or crowding the outdoor unit
What does Rinnai fault code L2 mean? (Q series inverter wall-mounted splits (HSNRQ25B, HSNRQ35B, HSNRQ50B, HSNRQ70B, HSNRQ80B systems; HINRQ indoor, HONRQ outdoor))
The compressor lost its normal running rhythm (out of step), so the system shut down. This is a subdivided version of the F1 module protection fault.
Likely causes:
- High system pressure from a blocked outdoor coil
- Unstable mains supply voltage
- Compressor fault
- Outdoor unit controller fault
Safe checks before you call:
- Check nothing is covering or crowding the outdoor unit
- Turn the system off at the isolator or breaker for 5 minutes, then restart
What does Rinnai fault code L3 mean? (Q series inverter wall-mounted splits (HSNRQ25B, HSNRQ35B, HSNRQ50B, HSNRQ70B, HSNRQ80B systems; HINRQ indoor, HONRQ outdoor))
One of the compressor’s electrical phases is missing or not connected, so the system shut down. This is a subdivided version of the F1 module protection fault.
Likely causes:
- Loose or damaged compressor wiring
- Compressor fault
- Outdoor unit controller fault
Safe checks before you call:
- Turn the system off at the isolator or breaker for 5 minutes, then restart
What does Rinnai fault code L4 mean? (Q series inverter wall-mounted splits (HSNRQ25B, HSNRQ35B, HSNRQ50B, HSNRQ70B, HSNRQ80B systems; HINRQ indoor, HONRQ outdoor))
The power module (IPM) that drives the compressor has failed or shut itself down. This is a subdivided version of the F1 module protection fault.
Likely causes:
- Power module failure on the outdoor controller
- Unstable mains supply voltage
- Compressor fault
Safe checks before you call:
- Turn the system off at the isolator or breaker for 5 minutes, then restart
Fault confirmed? Here is what to do next
A fault code is the starting point, not the fix. Start here:
- Air conditioner repairs – how we diagnose and fix Rinnai faults across Adelaide. Our fault find covers the full diagnosis, and it is on us if you go ahead with the repair.
- Repair or replace calculator – whether fixing your current system is the smarter money.
- Service and maintenance – regular servicing prevents most of the faults on this page.
- Air conditioner fault code lookup – all 15 brands in one place.
- All calculators and tools
Call us on 08 8296 7888 or book online and we will call or text you back ASAP.
Sources for this page
Every Rinnai code above is checked against these Australian documents. Open them yourself to verify anything on this page:
- AC Split Q Series SM (PDF) (rinnai.com.au)
- AC Split Inverter Cassette ERR (PDF) (rinnai.com.au)
- AC Split Inverter Cassette OM (PDF) (rinnai.com.au)
Rinnai fault code FAQs
Where do I find the fault code on a Rinnai air conditioner?
Check the remote or wall controller display first. Some models flash the indoor unit’s lamps in a pattern instead; the table above lists documented lamp patterns alongside their codes. If nothing is showing, the code may only appear while the fault is active.
Can I clear a Rinnai fault code myself?
You can reset the system by turning it off at the isolator or breaker for five minutes. If the code stays gone, it was a one-off. If it returns, the fault is real and needs a licensed technician, and repeated resets can cause further damage on compressor or refrigerant faults.
Does a Rinnai fault code mean I need a new air conditioner?
Usually not. Most codes point to repairable faults like sensors, fan motors or drainage. Our fault find gives you an honest verdict either way, and the fee is credited if you repair with us.
Are these Rinnai fault codes correct for Australian models?
Yes. Every code on this page was checked against Australian documentation (rinnai.com.au), not overseas lists, because the same code can mean different things in different markets. Meanings still vary between model series, so treat this page as reference and cross-check your unit’s manual.
Written by Oliver Hastings, T&K Airpower. Last updated 01/08/2026. Compiled from Australian sources including rinnai.com.au, so you can check every code against the official documentation. Fault code meanings vary between model series and controllers, so treat this page as reference only and never remove panels or work on the refrigeration or electrical parts of the system yourself.
