The electrochemical hydrogen compressor (EHC) uniquely avoids water generation at the cathode catalyst, causing the polymer electrolyte membrane (PEM) to dehydrate continuously due to electro-osmotic drag. This dehydration increases the PEM's ohmic resistance, underscoring the need for adequate hydration and water management. Our study measured the ion conductivity of a Nafion 117 PEM in a conductivity cell, finding a direct correlation between water content and ion conductivity, thus confirming hydration's impact on conductivity. Further analysis of hydrogen and steam output and impedance trends at different EHC voltages showed that at 1.70 V and 1.95 V―where water splitting occurs―water consumption in this process led to a significant reduction in hydrogen output (4.2% and 15.7% less than at 1.45 V, where no splitting occurs), suggesting optimal EHC operation occurs without water splitting.