HVAC Error Codes DirectoryMetro Vancouver
Comprehensive error code reference for furnaces, boilers, heat pumps, and ACs across all major brands
CALL NOW: 778-909-5731Ignition Lockout (Furnace)
Furnace has attempted ignition 3 times and failed, triggering a safety lockout with no heat.
Pressure Switch Stuck Open (Furnace)
Furnace pressure switch detects inadequate draft and prevents firing for safe exhaust venting.
Flame Sensor Failure (Furnace)
Flame sensor not detecting flame after gas valve opens, shutting down the burner.
Serial Communication Error (Heat Pump)
Mitsubishi heat pump communication lost between indoor and outdoor units.
Air Supply/Exhaust Blockage (Boiler)
Navien boiler detected blockage in air supply or exhaust venting and shut down.
Ignition Failure (Boiler)
Boiler failed to ignite burner after multiple attempts and locked out.
Overheating (Boiler)
Boiler water temperature exceeded maximum safety limit, triggering emergency shutdown.
PCB Fault (Heat Pump)
Daikin heat pump printed circuit board has detected an internal fault.
Freeze Prevention Active (Heat Pump)
Heat pump freeze prevention mode activated, temporarily stopping operation.
Flow Sensor Issue (Boiler)
Boiler flow sensor not detecting sufficient water flow for safe operation.
Limit Circuit Lockout (Furnace - Lennox)
Lennox furnace limit switch opened 5 times in one call for heat, locking out system.
Ignition Failure (Furnace - Lennox)
Lennox furnace failed to ignite after multiple attempts.
No Flame - Burner Shutdown (Boiler - Viessmann)
Viessmann boiler detected flame failure during operation and shut down burner.
Outdoor Temperature Sensor Fault (Boiler - Viessmann)
Viessmann boiler outdoor temperature sensor has failed or reading incorrectly.
Blocked Vent (Boiler - Weil-McLain)
Weil-McLain boiler vent blockage detected, system shut down for safety.
Inverter Module Error (Heat Pump - Trane)
Trane heat pump inverter drive module fault detected.
High Pressure Switch Trip
High pressure switch opened due to excessive refrigerant pressure.
Low Pressure Switch Trip
Low pressure switch opened due to suction pressure dropping too low.
Line Voltage Error (Furnace)
Furnace control board detected incorrect line voltage.
Water Pressure Sensor Error (Boiler)
Boiler water pressure sensor reading outside normal operating range.
Combustion Fan Error (Boiler)
Boiler combustion fan not operating at correct speed or has failed.
Compressor Sensor Error (Heat Pump)
Heat pump compressor temperature or pressure sensor has failed.
Rollout Switch Tripped (Furnace)
Rollout switch detected flames escaping burner compartment, furnace shut down.
Outdoor Unit PCB Error (Heat Pump - LG)
LG heat pump outdoor unit control PCB has detected a fault.
PCB Communication Error (Boiler - Navien)
Navien boiler control board communication error between main and display PCBs.
EEPROM Error (Heat Pump - Carrier)
Carrier heat pump outdoor control board EEPROM data corrupted.
Blower Motor Fault (Furnace)
Furnace control board detected blower motor circuit fault.
Low Gas Pressure (Furnace/Boiler)
Gas supply pressure too low for proper equipment operation.
Flame Amplifier Fault (Furnace)
Flame sense circuit not generating enough microamp signal.
Flue Gas Temperature Too High (Boiler)
Boiler flue gas temperature exceeded maximum safe limit.
Indoor Fan Motor Fault (Heat Pump - Samsung)
Samsung heat pump indoor fan motor not operating correctly.
Draft Inducer Motor Fault (Furnace)
Furnace draft inducer motor not running or not reaching proper speed.
Refrigerant Leak Detection (Heat Pump)
Heat pump refrigerant leak detection sensor has activated.