PREFILTER/POSTFILTER MAINTENANCE
NOTE: It is recommended to replace the battery, prefilter
and postfilter cartridges at least every 6 months of prod-
uct water use. Replace more often if they begin to plug
with sediments.
The prefilter and postfilter are replaceable sediment car-
tridges with activated carbon in its composition. See
Figure 25. You must periodically replace the prefilter and
postfilter cartridge. This will protect the RO membrane
from being destroyed by chlorine. It will also prevent the
filters from plugging with sediments.
You may notice a slower output of product water as the
prefilter and postfilter build up with sediments. Replace
the prefilter and postfilter cartridges when this occurs.
You should replace the battery whenever you replace the
cartridges.
RO MEMBRANE CARTRIDGE MAINTENANCE
The Reverse Osmosis cartridge is a tightly wound special
membrane. See Figure 25. The membrane reduces the
dissolved solids and organic matter. The life of the
Reverse Osmosis membrane cartridge depends mostly
on the pH and hardness of the supply water. (see specifi-
cations). Cartridge life is shorter with higher pH. For
example, if supply water pH is from 6.8 to 7.7, the car-
tridge may last for well over one year. However, car-
tridge life may be as short as 6 months if the pH is as
high as 8.5 to 10. Higher pH weakens the cartridge mem-
brane and causes pin-hole leaks, it's time to replace the
Reverse Osmosis cartridge when the production rate
and/or quality of product water drops. Product water
may begin to taste different or bad, indicating solids and
organics are passing through the Reverse Osmosis mem-
brane. See Reverse Osmosis cartridge replacement.
REVERSE OSMOSIS CARTRIDGE REPLACEMENT
Complete the following steps to replace the cartridges.
1. If possible,turn off the water supply to the RO system.
2. Remove (turn to the left) the pre filter cartridge from
the filter head to relieve pressure on the Reverse
Osmosis cartridge.
3. Remove the Reverse Osmosis cartridge.
4. Remove the postfilter cartridge.
5. Discard the cartridges in a proper manner.
6. install new cartridges in reverse order (postfilter,
Reverse Osmosis and then prefilter). Turn cartridges to
the right to re-attach to the filter heads.
7. Remove and replace the timer battery. See Figure 29.
8. Turn on the water supply to the RO system.
9. Purge the Reverse Osmosis membrane cartridge. See
page 17 for instructions.
Cover
Turn to the left
to remove
Postfilter
Cartridge
RO
Cartridge
Prefilter
Cartridge
Figure 25
PREFILTER/POSTFILTER CARTRIDGE
REPLACEMENT
Complete the following steps to replace the cartridges.
1. If possible, turn off the water supply to the RO system.
2. Remove the pre filter cartridge (turn to the left) from
the filter head. Then remove the post filter cartridge.
3. Discard the cartridges in a proper manner.
4. install new cartridges in reverse order (postfilter first,
then pre filter). Turn cartridges to the right to re-attach
to the filter heads.
5. Remove and replace the timer battery. See Figure 29.
6. Turn on the water supply to the RO system.
7. Purge the Reverse Osmosis membrane cartridge. See
page 17 for instructions.
Questions? Call The Kenmore Water Line 1-800-426-9345 or visit KenmoreWater.com
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