The A01 alarm appears on MCZ pellet stoves when a fault occurs during the ignition of the flame. It can occur when the pellet tank or the auger is empty (e.g. during the first ignition after refilling with pellets from an empty tank). Technically, this alarm is triggered when the flue gas temperature reaches a certain level (usually 55°C) a certain amount of time (approx. 15 minutes) after the unit has been lit.