The cartridge is installed in the cold-water line between the supply and the reservoir. Replacement depends on water hardness — usually annually.
Mounting
Isolate the cold-water supply, mount the Scale Control R holder level, and plumb it upstream of the reservoir.
Fit the cartridge
Twist the cartridge into the holder until seated. Open the water and check for leaks.
Maintenance
Replace the cartridge annually — sooner in very hard-water areas.