G
10 flashes
Moderate
Goodman · HVAC Systems (AC, Furnaces & Heat Pumps)
Line Voltage Polarity Reversed
Quick Answer
Error code 10 flashes on your Goodman HVAC Systems (AC, Furnaces & Heat Pumps) means: Line Voltage Polarity Reversed. This is usually fixable — see the step-by-step guide below.
Likely Causes
  1. Line and neutral reversed on the incoming power supply
  2. Faulty outlet or disconnect with reversed internal wiring
  3. Circuit breaker panel wiring error
  4. Bootleg ground in the electrical system
How to Fix It
1
Verify polarity at the furnace disconnect using a multimeter or polarity tester
2
Check that hot connects to the correct terminal and neutral to the neutral terminal
3
Test the dedicated circuit at the electrical panel for proper wiring
4
Correct any reversed wiring found at the disconnect or junction box
5
A licensed electrician should investigate if the issue is within the electrical panel
Pro Tip
This fix requires some technical knowledge. If you're unsure about any step, consider contacting support or a qualified technician.
Parts You May Need
Electrical wire
Wire connectors
Disconnect switch (if faulty)
Related Error Codes
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