Drinking or crafting requires clean water, and buying that can be expensive, so the best idea is to buy and use a Kettle to produce clean water. Kettles can be bought from experienced Engineers or their vendors.

The next part will be to gather some water. For this, you will need an item like a pitcher or water skin and any type of water source like a barrel, lake, sea, etc. Double-click on such an item and target the water source. Remember that such places usually contain dirty and contaminated water that can cause some serious health problems.

When both needed items (water + kettle) are obtainable, you can double click on Kettle and the menu like this will open:

Then move the pitcher or any other container with water to the free slot of your kettle:

Before you will be able to click apply and boil the water, you need to find a place with a fire source in order to boil it. It could be some kind of oven or fire like this:

After clicking apply, the process of boiling will start and can be observed by moving the cursor over your kettle:

After Boiling is completed water will be purified and can be used for drinking or crafting.

Additional info: – There are some legends about places with clean water that do not demand boiling – Not every well contains clean water! – Clean water is required for crafting