Compression fittings use a ferrule and nut for a tight seal (ideal for water lines), while push-to-connect fittings snap into place (no tools needed, great for quick repairs).

Check for improper threading, missing thread sealant, or vibration. Use threadlocker (Loctite) or a locking nut for stability.

Tighten the fitting with a wrench (don’t overtighten), or replace the O-ring/washer. For threaded leaks, wrap Teflon tape clockwise.