HVAC Error Codes by Category
Browse diagnostic codes by equipment type. Every brand, every fault code — step-by-step troubleshooting from service manuals.
On-demand hot water error codes for Rinnai, Navien, Noritz, Rheem, and more.
Browse Tankless Water Heaters Codes →Ductless system error codes for Mitsubishi, Daikin, Fujitsu, Gree, and LG.
Browse Mini-Splits & Heat Pumps Codes →Forced-air furnace fault codes for Carrier, Goodman, Lennox, Trane, and York.
Browse Furnaces Codes → Coming Soon
Smart and programmable thermostat error codes — coming soon.
Storage tank water heater codes for AO Smith, Bradford White, Rheem, and State.
Browse Tank Water Heaters Codes →