My dads gone on holiday and im looking after his tank and the inkbird ict-306a has an e5 error what do i need to do?

[louie_ra]

My dads gone on holiday and im looking after his tank and the inkbird ict-306a has an e5 error what do i need to do? Please help

 

[Dr. Phil]

What is the temp of the tank? Based on a search that error likely means the heater has been on for longer than allowed. This could mean the heater is set too low or that it is not heating.