Step 3 · Install the New Toilet Fill Valve

This is the step people usually slow down on. Go finger-tight first, then a quarter turn. No rush — replay the clip whenever it helps.

Insert the new fill valve into the tank opening and secure it with the lock nut. Hand-tighten the nut securely; avoid over-tightening. Connect the water supply line to the new fill valve and adjust the float height as per the manufacturer’s instructions (usually to the marked level).