HVAC, Appliance, CNC, and VFD Error Code Repair Guides

Browse repair guides for HVAC, appliances, refrigeration, CNC alarms, VFD faults, generators, boilers, water heaters, and commercial equipment.

• Mitsubishi FR-A800 E.OC1 Overcurrent Fault

  Updated: 16 Sep, 2026

  Mitsubishi FR-A800 E.OC1 fault guide for acceleration overcurrent, ramp time, motor cable insulation, output reactors, load jams, and motor data.

• Mitsubishi U1 Error Code — Causes & Fix

  Updated: 16 Sep, 2026

  Mitsubishi U1 guide for voltage imbalance, phase loss, loose disconnect lugs, power sags, surge events, and inverter-board checks.

• MYCOM Compressor Fault Codes - N-Series, F-Series, MYPRO

  Updated: 16 Sep, 2026

  MYCOM compressor fault guide for N-series, F-series, ComPAC, and MYPRO systems: oil pressure, discharge temperature, vibration, and reset limits.

• Navien NCB Combi Boiler Error Codes - E003, E012, E351

  Updated: 16 Sep, 2026

  Navien NCB combi boiler code guide for ignition, flame loss, condensate pressure, low water pressure, fan faults, flow sensors, and 3-way valves.