Heater leaks water from the bottom of the cabinet during or after operation.

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

• Identify source: Remove the front and side panels and observe where water is originating. Use a flashlight while the pump is running.
• Check unions and fittings: Tighten any loose PVC unions at the inlet and outlet. Do not overtighten to the point of cracking.
• Inspect header gaskets: Look for seepage around the plastic or metal headers where they meet the heat exchanger.
• Assess heat exchanger: If water appears from the center of the exchanger or combustion chamber, the exchanger may be cracked and will require replacement.