Canon BJC 3000 Reference Manual page 145

4
When a confirmation message appears, make sure that the printer is
switched on and then click the OK button. Print head cleaning begins. (It
takes about 40 seconds until print head cleaning is completed and the
POWER lamp stops flashing.)
5
Print a nozzle check pattern to confirm the success of normal print head
cleaning.
Printing a Nozzle Check Pattern
Cleaning the Print Head
Routine Maintenance 145