The most common and most likely answer to this crossword clue is the 5 letter word DRIPS
I've seen this crossword clue in The Daily Telegraph
D
R
I
P
S
Buddy explains!
The straight part
We know that "Spots the sign of a faulty washer" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case spots the sign of a faulty washer = drips.The cryptic/wordplay part
In cryptic crossword there's often an wordplay/cryptic part as well.This part involves a more complex hint, such as an anagram, homophone, hidden word, etc.
Sadly, We don't have an explanation for this specific crossword clue yet.
What does DRIPS mean?
DRIPS noun- A drop of a liquid.
- A falling or letting fall in drops; act of dripping.
- An apparatus that slowly releases a liquid, especially one that intravenously releases drugs into a patient's bloodstream.
- A limp, ineffectual, or uninteresting person.
- That part of a cornice, sill course, or other horizontal member, which projects beyond the rest, and has a section designed to throw off rainwater.