GE JVM1840 Owner's Manual page 32

Other features your model may have.
Switch places after 1/2 time
Switch places after 1/2 time
32
Shelf and Reheating
s
To reheat on 2 levels
OR
s
To reheat 2 dishes on the lower level:
Multiply reheat time by 1
1
2 Switch places after 1/2 the time.
1 / .
2