Look up error codes from top boiler brands. Understand what they mean and when to call an emergency technician.
Navien boiler detected a blockage in the air supply or exhaust venting system and shut down.
Navien boiler failed to ignite the burner after multiple attempts and locked out.
Navien boiler water temperature exceeded the maximum safety limit, triggering emergency shutdown.
Navien boiler flow sensor is not detecting sufficient water flow for safe operation.
Viessmann boiler detected flame failure during operation and shut down the burner.
Viessmann boiler outdoor temperature sensor has failed or is providing an incorrect reading.
Viessmann boiler domestic hot water temperature sensor is reading outside normal range.
Weil-McLain boiler vent blockage detected, shutting down the system for safety.
Weil-McLain boiler has locked out after repeated ignition failures.
Weil-McLain boiler system water pressure is too low for safe operation.
Navien boiler temperature sensor (NTC thermistor) is reading outside the valid range.
Navien boiler water pressure sensor is reading outside the normal operating range.
Navien boiler detected a gas valve electrical fault and shut down the system.
Navien boiler combustion fan is not operating at the correct speed or has failed.
Navien boiler flow switch is stuck open or not detecting water flow during DHW demand.
Navien boiler control board communication error between main and display PCBs.
Viessmann boiler gas pressure switch indicates insufficient or excessive gas pressure.
Viessmann boiler flue gas temperature has exceeded the maximum safe limit.
Navien boiler antifreeze function has activated due to low water temperature risk.
Buderus boiler heat exchanger temperature exceeded the safety limit, triggering shutdown.
Buderus boiler burner failed to ignite or lost flame during operation.
Lochinvar boiler temperature sensor has failed open or short circuit.
Lochinvar boiler low water cutoff sensor has detected insufficient water level.