It would be easier to state the programming something like to where:
if DOW M-W-Th-Sa
type statement. Then flip it for the other heater. This will let heaterA work on odd days and heaterB work on even days. This gives them equal amount of wear and usage.
To do it by DOW (day of week) is easier and less typing than making it every other hour.
That works, I just would like to rotate the heaters somehow to ensure they are both working. In the case you posted can you show me how you would program that in Apex?
Sorry Apex programming newbie!