GE GNUT05Z01 Owner's Manual page 10

About the water filtration system.
Flush Procedure
10
Whenever water of unknown quality is passed through the GE
Water Filtration System, filter elements should be discarded and
the filtration system flushed.
Circumstances that may require flushing the system are:
Boil-Water Advisory.
Flooding of the GE Water Filtration System.
Long-term non-use.
The procedure for flushing the GE Water Filtration System is:
See Filter Cartridge Replacement section on page 8 and follow steps
1, 2, 3, and 4.
Next, reinstall the sumps (without the filter elements), turn water
on, and flush water through the faucet for one minute.
Then, turn water off, remove sumps, empty water out of sumps
and install new filter elements.
Follow steps 6–9 on page 9, Filter Cartridge Replacement section,
to complete.