To clean a coffee maker, you can use white distilled vinegar and water. Here are the steps to follow:

1. Fill the water tank of the coffee maker with a mixture of one-half water and one-half white vinegar.
2. Turn the coffee maker to the brew cycle and allow the cycle to brew halfway.
3. Turn off the coffee maker and let the cleaning mixture steep for 30 to 45 minutes.
4. Turn the machine on and allow the brew cycle to complete.
5. Discard the white vinegar cleaning solution and refill the water tank with clean water.
6. Turn on the brew cycle and allow all the water to run through the system.
7. Discard the water, refill the tank, and repeat the brew cycle.
8. When the last cycle is completed, pour out one cup of the water and discard the rest.
9. Wash the carafe and other removable parts, such as the lid and filter basket, in the sink with warm, soapy water or in the dishwasher if marked dishwasher safe.
10. Rinse and towel dry, or set aside to air dry.

Its important to note that some coffee brands, including Lavazza and Smeg, do not recommend cleaning your coffee maker with vinegar as the strength of the acidity can rot the rubber seals and parts if you use vinegar regularly, which will limit its life. However, using vinegar occasionally to clean the water reservoir is safe.