Water leaking from the bottom of the heater cabinet.
Safety Warning
This repair may involve working with high voltage components or water connections. Always unplug the appliance before removing any panels.
If you are not confident in your ability to perform this repair safely, we strongly recommend contacting a professional technician.
Possible Causes
How to Fix / Troubleshooting
Safety first: Turn off power and gas. Shut off water flow to the heater and relieve system pressure before opening plumbing.
Steps to locate and address leaks:
- Inspect headers and unions: Remove front and side panels. Check inlet/outlet unions, header gaskets, and drain plugs for drips. Tighten unions and replace O‑rings or gaskets as needed.
- Check heat exchanger: Look for water seeping from the exchanger tubes or between fins. Green/blue staining on copper indicates leaks.
- Freeze damage: In cold climates, inspect for split manifolds or cracked plastic/bronze headers from freezing.
- Pressure test: A professional can pressure‑test the heat exchanger to confirm leaks. Replace the heat exchanger or complete heater if it is cracked.
Note: Do not operate the heater with an internal leak; it can damage burners and controls.
Repair Difficulty
Required Part
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