never fails

never fails

Is always effective; always does what's desired or intended. If none of these things resolve the issue, turning your computer on and off again never fails. I'm telling you, drink this—it never fails to get rid of a hangover.
See also: fail, never
Farlex Dictionary of Idioms.

something never fails

a particular thing always works. My old folk remedy for hiccups never fails.
See also: fail, never
McGraw-Hill Dictionary of American Idioms and Phrasal Verbs.
See also:
  • as always
  • it was ever so
  • twa
  • never a dull moment
  • thus
  • it was ever thus
  • you can't always get what you want
  • always be on (one's) guard
  • the first step is always the hardest
  • first step is always the hardest