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.

• Raymond Forklift Fault Codes - 100, 500, and 900 Series

  Updated: 18 Sep, 2026

  Raymond forklift fault codes for 7000 series, 8000 series, and Reach-Fork trucks: error codes, causes, and troubleshooting steps.

• State Water Heater Error Codes - Gas, Electric, and Hybrid

  Updated: 18 Sep, 2026

  State water-heater error-code guide for gas, electric, and heat-pump models, including LED flashes, display faults, sensors, and elements.

• Vertiv Liebert UPS Fault Codes - GXT, EXS, APM, NXL

  Updated: 18 Sep, 2026

  Vertiv Liebert UPS fault guide for GXT, EXS, APM, NXL, and three-phase systems: battery faults, bypass events, fans, inverter trips, and service limits.

• Cummins Onan Generator Fault Codes

  Updated: 18 Sep, 2026

  Cummins Onan generator fault guide for RV QG, RS, and MDKD codes, overcrank, underspeed, oil pressure, AVR, and service parts.