Water leaking from the bottom or sides of the heater cabinet

Safety First: Turn off power and gas. Water inside the cabinet can contact electrical components.

• Identify source: Remove access panels and use a flashlight to trace the leak. Check around the inlet/outlet headers, unions, and drain plugs.
• Check unions and fittings: Tighten any loose unions or threaded fittings. Replace O-rings or gaskets if they are cracked or flattened.
• Differentiate condensate vs. leak: On condensing models, some water discharge is normal from the condensate drain. Ensure the drain line is connected and routed properly.
• Heat exchanger inspection: If water appears to be coming from inside the heat exchanger or header casting, the exchanger may be cracked and will likely need replacement by a professional.