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.

• Haas Alarm 131 — E-Stop Chain Fault Fix

  26 Apr, 2026

  Haas Alarm 131 points to an open E-stop chain. Check buttons, door interlocks, safety relays, and wiring without bypassing safety circuits.

• LG Mini-Split CH22 Indoor Fan Motor

  26 Apr, 2026

  LG mini-split CH22 guide for indoor fan motor lock, overcurrent, wiring checks, blower faults, PCB checks, and repair decisions.

• Lochinvar Knight Boiler Error Messages — Complete Display Guide

  26 Apr, 2026

  Lochinvar Knight Boiler Error Messages - Complete Display Guide: likely causes, checks, and repair decisions before replacing parts.

• Rheem Heat Pump Error Codes

  26 Apr, 2026

  Rheem RA14, RA15, and RP15 heat pump fault codes. Decode E1, E2, E4, and E5 sensor, high-pressure, and low-pressure trips.