Do this first

Check the container and heat source together, then inspect the water after the action completes. Heat, a connected sink or an old screenshot alone does not establish that the current fluid is safe.

Evidence boundary. 42.21 officially expands purification to many more containers in appropriate oven types. This guide does not supply an unverified compatibility matrix or boil timer.
Original water illustration accompanying this checking guide.
Original illustration, not an in-game screenshot or a verified layout.

The 42.21 change is about compatible combinations

The official patch notes add purification support for many more fluid containers in the appropriate oven type. That change does not mean any container works on any heat source. If your old setup fails, check the current item’s available actions and the appliance rather than following a picture from an earlier patch.

Before experimenting, keep your known-safe drinking supply separate. Work with one container so that you can inspect exactly what went in and what came out. Mixing the trial water into your reserve makes a failed check harder to recognize.

Source: The Indie Stone · full 42.21 patch notes · Official patch notes

Water check sequence: reservoir supply, fixture connection, then fluid safety. Connection does not certify purity.SupplyConnectionSafetyCHECK EACH SEPARATELY
Original troubleshooting schematic. It illustrates a checking workflow, not a simulation of game rules.

Use a small purification check

  1. Identify the exact container and read its current fluid information. Record the unsafe or tainted indication before heating.
  2. Check whether that item is accepted by your chosen appliance and whether the necessary action is available. Read any tooltip describing a restriction.
  3. Confirm that the appliance actually has its required power or fuel and that the intended action completes. Placing an item near a stove is not the same as a completed supported process.
  4. Inspect the fluid again after the process. Use the current unsafe or tainted indication, not the fact that the container became warm.
  5. If the indication remains, stop and compare the container–appliance combination with current source information. Try a known supported combination in a separate control test rather than repeatedly guessing a duration.

A connected sink is a different question

A plumbing connection answers whether a fixture can obtain water. It does not, by itself, prove that the fluid is suitable for drinking in your patch. Inspect the fluid delivered by the fixture. Do not apply an old “all plumbed rainwater is automatically purified” answer without a current check.

If your immediate problem is survival rather than the layout, use a drinking source the current game identifies as safe while you investigate the connection. Preserve the uncertain water for the test; do not consume it simply to find out whether a guide was right.

Source: PZWiki · Water · Older wiki background

What to record when a supported process fails

Keep the patch, mod list, container name, appliance, initial fluid label, completed action and final fluid label together. A report that just says “I boiled water” omits the very combination changed by this update. We do not give a universal timer or declare every bottle oven-safe. Those details require an item-level source or a current-game test.

Choose the next branch

Sources & verification

Original checking steps are editorial recommendations. This site has not run a game test or inspected a local 42.21 installation. Source review and page update dates describe different work.

Prepare a correction for this guide