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
Hope I could help you.