By
eHow Home & Garden Editor
Difficulty: Moderately Easy
Things You’ll Need:
Step1
Close the cold-water water valve that feeds the filter.
Step2
Release any pressure in the line by turning on the cold- and hot-water faucets; leave them open. Some filter models also have a vent valve on top of the filter that you press to release pressure.
Step3
Turn the sump clockwise using the sump wrench that came with the filter to remove it. Be careful: It's most likely full of water.
Step4
Locate and set aside the O-ring seal.
Step5
Remove and throw away the used filter cartridge.
Step6
Clean the inside of the sump with hot, soapy water and rinse it very well. (Remember that you turned the water off at the sink you're working on.)
Step7
Insert the new filter cartridge in the sump. Check the label on the filter - some are designed to be installed in a specific direction.
Step8
Grease the O-ring with clean silicone lubricant. Be sure that it seats completely in its groove.
Step9
Line up the sump with the filter head and screw it back on.
Step10
Tighten the sump by turning it counterclockwise.
Step11
Repeat these steps for the other sump if you have more than one on the filter unit.
Step12
Stick the reminder label that typically comes with the filter onto the sump.
Step13
Open the water valve slowly and fill the filter. If you have a vent valve, hold it down while the filter is filling to keep air out of the line.
Step14
Turn off the faucets and check the unit for leaks.
Step15
Run the water for 5 minutes to clear out carbon particles that have settled in the cartridge.