Liquid ejection apparatus

A liquid ejection apparatus comprising:

• a head including a plurality of types of nozzle groups, each of the plurality of types of nozzle groups being formed by nozzles, the plurality of types of nozzle groups having different liquid ejection conditions, the plurality of types of nozzle groups including a first nozzle group and a second nozzle group;
• a cap configured to cover the nozzles forming the plurality of types of nozzle groups;
• a pump configured to apply pressure to liquid in the head;
• and
• a controller configured to perform:
• in a case where a particular condition is satisfied, acquiring abnormal nozzle information, the abnormal nozzle information relating to a number of first abnormal nozzles, a number of second abnormal nozzles, and a total number of abnormal nozzles, the first abnormal nozzles being abnormal nozzles having abnormality in ejection of liquid among the nozzles forming the first nozzle group, the second abnormal nozzles being the abnormal nozzles among the nozzles forming the second nozzle group, the total number of abnormal nozzles being a total number of the abnormal nozzles among the nozzles forming at least two nozzle groups of the plurality of types of nozzle groups;
• determining, based on the abnormal nozzle information, whether a purge is to be performed, the determining including determining that the purge is to be performed in a case where at least one of a plurality of purge conditions is satisfied, the plurality of purge conditions including a first purge condition that the number of the first abnormal nozzles is larger than or equal to a first threshold, a second purge condition that the number of the second abnormal nozzles is larger than or equal to a second threshold, and a third purge condition that the total number of abnormal nozzles is larger than or equal to a third threshold;
• and
• in response to determining that the purge is to be performed, controlling the pump to perform the purge, the purge being discharging liquid from the nozzles forming the plurality of types of nozzle groups by driving the pump in a state where the cap covers the nozzles forming the plurality of types of nozzle groups.