Seeley International Pty Ltd

E1 – High Pressure Protection

Description:
System shuts down when refrigerant pressure is too high. Error appears on wall control, indoor unit, and outdoor PCB.

Causes:

• High-pressure switch faulty or loose plug connection (check pins inside plug; bent pins can cause poor contact).
• Outdoor fan not operating or spinning slowly.
• Dirty filters or coils; poor ventilation around outdoor unit.
• Refrigerant issues: blockages, EXV malfunction, air in system, or overcharge.

Action:

• Clean coils and filters; ensure clear airflow.
• Check fan operation and clearances.
• Test refrigerant pressures and EXV.
• Inspect high-pressure switch and wiring.

E6 – Communication Error

Description:
Outdoor PCB does not receive correct signal for 3 minutes; system stops until reset or fault cleared.

Causes:

• Low or unstable power supply.
• Indoor/outdoor unit mismatch (e.g., WSHV‑S ≠ WCHV‑T).
• Damaged or incorrectly wired comm cable.
• PCB fault in indoor or outdoor unit.
• Faulty electronic components (reactor, motor, sensors).
• Condensate pump wiring fault on wall splits.
• Incorrect parameter settings (Modbus / Long Distance).

Action:

• Confirm correct model pairing.
• Check voltage at isolator.
• Inspect comm wiring and wall control cable.
• Test PCBs and reset system.

E9 – Water Overflow (Ducted Systems)

Description:
Float switch activates when water level is too high; system stops and displays E9.

Causes:

• Blocked drain line.
• Pump not connected properly to indoor PCB.
• Faulty pump or float switch.
• Indoor main PCB fault.

Action:

• Clear drain line.
• Check pump wiring and float switch.
• Replace faulty components.
  (Note: Pump runs continuously in cooling/dry mode; after compressor stops, pump runs for 3 mins.)

P6 – PCB Communication Fault (Ducted)

Description:
Main PCB and Drive PCB in outdoor unit fail to communicate for 30 seconds.

Causes:

• Loose or damaged comm cable.
• Rodent/insect damage or corrosion on PCB.
• Power supply issues.
• Faulty main or drive PCB.

Action:

• Inspect comm cable and connectors.
• Check PCBs for damage.
• Verify voltage and wiring.

C4 / C5 / LP – Jumper Plug Errors

Ensure jumper cap is present, correct size, and fitted properly. Transfer jumper from old PCB when replacing.

F0–F5 – Sensor Faults

Inspect thermistor plugs and harness; measure resistance against spec; replace faulty sensor or PCB.

H5 – IPM Protection

Inverter module shut down due to overheat or overcurrent.
Check heat sink screws and thermal paste; inspect airflow and coil condition; verify voltage stability and compressor health.

H6 – Fan Motor Fault

Indoor or outdoor fan motor not operating correctly.
Remove obstructions/debris; check for seized bearings; test motor windings and PCB output.

Tip: Full error code tables (including P-codes, U-codes, PH/PL) and LED patterns for outdoor PCBs are in the service guide.

⚠️ Error Codes “E” – System Protection & Communication

• E0 – Water Pump / Voltage Protection
  Indicates water pump faults (drain overflow or weak start-up current). The compressor and fan may halt ~3 minutes later. Check pump and float; verify supply voltage.

• E1 – High‑Pressure Protection
  Triggered by: blocked outdoor coil, refrigerant overcharge, restricted flow, or faulty high-pressure switch. Inspect condenser, airflow, and pressure switch.

• E2 – Freeze / Low‑Temperature Protection
  Indoor coil icing or frozen line detect. Check for low refrigerant or blocked airflow.

• E3 – Low‑Pressure Protection
  Caused by refrigerant undercharge/leak or dirty filters. Check charge levels and pressure switch.

• E4 – Compressor Discharge Over‑Temp
  Discharge line overheating; detected by PCB. May auto shutdown after repeats. Check discharge line temperature and airflow.

• E5 – Over‑Current / Voltage Fluctuation
  Triggered by unstable power or voltage out-of-range. Check supply, wiring, and electrical stability.

• E6 – Indoor ↔ Outdoor Communication Failure
  One of the most common codes. Probable causes: loose/damaged communication wires, faulty control boards, mismatched unit pairing (e.g., S vs T models). Reset power, inspect wiring/PCB, ensure correct model pairing.

• E7 – Mode Conflict
  Indoor and outdoor units set to opposing modes (e.g., heating vs cooling). Sync the mode, then reset the system.

• E8 – Indoor Fan Motor or PCB Fault
  Indicates indoor fan motor issues or PCB failure. Check fan motor connection, operation, and indoor PCB.

• E9 – Water‑Pump / Tray Overflow
  Specific to units with drain pumps. Check pump, float switch, tray levels.

Error Codes “F” – Sensor Faults

Often require component replacement; check sensor resistance and connections first.

Error Codes “H” – Heating & High-Temperature Protection

• H0 – Heating tube high temperature
• H1 – Defrost mode/status, not an error
• H2 – Static de-dusting (filter maintenance)
• H3 – Compressor overload
• H4 – Evaporator/condenser overload
• H5 – IPM protection (power module fault; shutdown on overcurrent/temperature)
• H6 – Outdoor fan motor failure or IPM overheat
• H7 – Compressor maloperation
• H8 – Dehumidification tray full or IPM overheating for fan
• H9 – Loss of fan synchronization

Error Codes “P” – Motherboard & Drive Communication

• P0 – Drive module reset failure
• P5 – Compressor current protection
• P6 – Communication error between main and drive PCB
• P7 – OFC IC temperature sensor fault
• P8 – PFC IC over-temperature error

Error Codes “C” & “U” – Jumpers and Power Issues

• C5 – Jumper cap missing or incorrectly installed on PCB
  Ensure proper jumper transferred on PCB replacement.
• U-codes (e.g., U1, U2, U3…) – Likely CPU EEPROM faults, phase current issues, voltage drop, compressor demagnetization.
  Inspect PCB/modules.

Recommended Troubleshooting Workflow 

1. Power Reset & Observe

   • Turn the unit OFF at the isolator or breaker for 2–3 minutes, then restart.
   • Watch if the error code reappears—this rules out temporary glitches.

2. Check Wiring & Connections

   • Inspect communication cables between indoor and outdoor units (especially for E6 errors).
   • Look for loose plugs, damaged insulation, or corroded terminals.
   • Confirm sensor plugs (F-series codes) are firmly seated and not broken.
   • Verify jumper caps on PCBs (C5 codes)—they must be in the correct position.

3. Check Refrigerant & Coil Conditions

   • For E1–E4(pressure or temperature faults):
     • Clean indoor and outdoor coils.
     • Check airflow (filters, fan operation).
     • Connect gauges and confirm suction/discharge pressures match spec.
     • Look for signs of overcharge or leaks.

4. Electrical Health Check

   • For E5, H5, P-series:
     • Measure supply voltage at the isolator—should be stable within spec.
     • Check current draw on compressor and fan motors.
     • Inspect inverter module heat sink and ensure screws are tight (IPM protection).
     • Look for burnt marks or swelling on capacitors.

5. Confirm Correct Pairing & Mode

   • Ensure indoor and outdoor units are matched models (e.g., S-series indoor with S-series outdoor).
   • If E7 appears, both units must be in the same mode (cooling or heating).
   • Reset mode conflicts by turning both units OFF, then reselect the correct mode.