Heater is running but there is water leaking from the bottom of the cabinet

Safety: Turn off power and gas. Shut off water flow to the heater to prevent further leakage.

• Identify leak source: Remove the front and side panels. Use a flashlight to trace water back to its origin: the Heat Exchanger, inlet/outlet headers, or unions.
• Check unions and gaskets: Tighten inlet and outlet union nuts by hand, then slightly with a wrench if needed. Inspect header gaskets for signs of bulging or deterioration.
• Look for corrosion: Green or white corrosion on the copper tubes or headers often indicates a pinhole leak in the exchanger, which typically requires replacement of the exchanger assembly.
• Inspect for freeze damage: If the heater was not winterized, look for split plastic headers or cracked manifolds. Replace any damaged Inlet/Outlet Header components.
• Dry and test: After repairs, dry the cabinet, restore flow, and monitor for new leaks.