A.O. Smith heater shows E15; unit may shut down unexpectedly
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
Critical safety: A tripped rollout switch indicates dangerous combustion. Turn off gas and power immediately. Do not bypass the switch.
- 1. Locate rollout switch: Find the small manual-reset limit switch near the burner opening or combustion chamber. It may have a red reset button.
- 2. Inspect for soot and discoloration: Look for signs of flame escaping the burner area, soot on the front of the heater, or melted wiring. If present, stop and call a professional.
- 3. Reset switch: After the unit has cooled, press the reset button on the rollout switch. If it clicks, it was tripped.
- 4. Check venting and burner: Ensure the flue is not blocked and the burner is clean. Do not operate the unit if you suspect blockage.
If the rollout switch trips again, do not reset it. Have a qualified technician inspect the burner, venting, and heat exchanger for serious hazards.
Repair Difficulty
Required Part
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