Although there are a number of methods used to sterilise baby bottles, such as using cold water sterilisation tablets, boiling, or with a microwave steamer, using a Steam Sterilizer is one of the easiest and most convenient ways of getting the job done. However mineral scale deposits from inside the unit and around the heating coil must be removed periodically to keep the unit operating at peak efficiency. According to the Philips FAQ web page, there are two quick and easy ways of doing this.
Dissolve one 10g sachet of citric acid in 200ml of cold water. Remove the lid and pour the solution into the machine. Do not replace the lid.
Activate the Mode 1 heating cycle for two minutes.
Turn the sterilizer off and unplug it from the outlet. Let the machine stand for 30 minutes to allow the citric acid solution to continue descaling during the cooling process.
Drain the sterilizer and rinse the inside with clean running water.
Plug the sterilizer in and pour exactly 90ml of water into the unit. Replace the lid and switch the machine to Mode 1. Run a full sterilisation cycle on the empty machine. Drain and wipe dry with a clean paper towel.
Pour 100ml of with white vinegar into a glass measuring jug containing 200ml of cold water. Stir well.
Unplug the sterilizer. Pour the vinegar/water solution into the unit and replace the lid. Leave overnight for the vinegar to dissolve lime scale deposits completely.
Empty the sterilizer and rinse thoroughly with clean running water.
Plug the machine in. Add exactly 90ml of water and replace the lid.
Select Mode 1 and run a full sterilisation cycle on the empty machine. Rinse and wipe dry with a clean paper towel.
Do not switch the sterilizer on while descaling with white vinegar.