E11
Amazon Smart Thermostat Fan (G Terminal) Output Fault

Thermostat displays E11 and fan runs unexpectedly or not at all

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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.

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Possible Causes

Shorted G wire to C or R, Loose G connection at furnace control board, Failed fan relay on thermostat main board

How to Fix / Troubleshooting

Safety: Turn off power to the furnace/air handler at the breaker.

  • Inspect G wire at thermostat: Remove the thermostat and verify the G wire is fully inserted in the G terminal and not touching adjacent terminals.
  • Inspect G wire at furnace: At the control board, confirm the G wire is secure and not pinched or damaged.
  • Test with G disconnected: With power off, disconnect the G wire at the furnace control board. Restore power and see if E11 clears. If it does, the issue is in the field wiring or blower control. If not, the thermostat relay may be faulty.

If E11 persists with G disconnected at both ends, replace the thermostat.

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Repair Difficulty

Medium 3/5

Required Part

Amazon Smart Thermostat Main Control Assembly
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