What is the difference between error 101 and other Ariston error codes related to ignition?

Error 101 specifically points to a *failure to detect* a flame. Other ignition errors, like codes related to ignition failure before flame detection (e.g., codes related to the ignition transformer directly), indicate problems *before* the flame is even established. Error 101 means the boiler tried to ignite, but the sensor didn't confirm a stable flame.