When your pool skimmer fails to effectively skim the surface, it is often due to one of several common issues. First, check the water level; an improper level can hinder performance. Additionally, insufficient suction at the skimmer can impact its ability to collect debris. Lastly, inspect the weir door for any obstructions or malfunctions that may prevent it from operating correctly. Addressing these factors will help restore your skimmer's functionality and keep your pool clean and clear.