The answer to 'drain trap constantly running' is that a constantly running drain trap is usually caused by a faulty or improperly installed P-trap. The P-trap is the curved pipe under your sink or tub that holds a small amount of water to prevent sewer gases from entering your home. If the trap is cracked, not properly sealed, or has an improper slope, it can allow water to continuously drain through it.
Other common causes include a blocked vent pipe, a clogged drain, or high water pressure in the plumbing system. Symptoms include a constantly running or gurgling drain, slow draining, and potential water damage around the fixture.