Grohe Blue filter cartridge replacement
The Grohe Blue filter cartridge (model 40547001) is rated for 1,500 liters (approximately 400 gallons) or 6 months, whichever comes first. A filter life LED indicator on the Blue faucet head illuminates red when replacement is due. To replace: shut off the cold water supply via the T-valve below the filter housing (no need to shut the main supply). Twist-lock the filter housing lid counterclockwise, remove the depleted cartridge, insert the new cartridge, and twist-lock the lid clockwise. Open the supply and flush 2-3 liters through the Blue faucet before drinking. Replacement cartridges cost approximately $55-65 and are available from Grohe authorized dealers and plumbing supply houses.
Grohe Blue CO2 cylinder exchange
The CO2 cylinder provides carbonation for Grohe Blue sparkling water modes. The cylinder contains approximately 425 grams of food-grade CO2. At 1 liter of sparkling water per day, the cylinder lasts approximately 1.5-2 months. When the cylinder is empty, the sparkling modes stop working (still mode continues). Exchange procedure: turn the carbonation regulator counterclockwise to release pressure, remove the empty cylinder from the bracket, insert a pre-filled exchange cylinder, and tighten the regulator clockwise. CO2 exchange cylinders are available from Grohe dealers and selected appliance retailers. Do not use non-food-grade CO2 cylinders or cylinders from incompatible systems.
Grohe Red boiler descaling
The Grohe Red 4-liter boiler tank accumulates scale in hard water areas. Descale the boiler annually in moderately hard water (7-14 GPG) or every 6 months in very hard water (above 14 GPG). Grohe recommends their Grohe Red descaling solution (model 40404001). Procedure: put the system in descaling mode via the faucet control (hold the activation button for 5 seconds until the indicator light changes). This mode opens the boiler drain valve. Add the descaling solution per the Grohe instructions, run the descaling cycle, then flush with 3-4 full tanks of fresh water before returning to normal use. Grohe Red descaling is documented in the system manual -- refer to the specific model manual for your unit as the procedure varies slightly between the Grohe Red Duo and Grohe Red II variants.