I think, these translations would be best:

* chilled water = kaltes/gekühltes Wasser (*gekühlt* sounds a bit better)

* ambient water --> there are multiple possible translations:

 * **raumtemperiertes** Wasser (this is an **official word** by producers of water dispensers)
 * ungekühltes Wasser (like you already said)
 * laues Wasser

* hot water = warmes/heißes Wasser