HVAC Sales Master

Fault Code Lookup

HVAC Sales Master
6
115 volt AC power reversed, ignitor (Triac) fault, poor grounding, or system voltage too low
This code typically points to
  • Reversed polarity
  • Ignitor triac fault
  • Poor grounding
  • Low system voltage
Next checks to confirm
  1. Verify polarity, ignitor/triac condition, grounding, system voltage
Escalation
Ignition/control fault
Reset behavior
Clears when electrical fault corrected.
Urgent
Fix now
⚠ Cross-generation conflict
Code 6 on your Trane/American Standard furnace means different things depending on platform. On UD2/DD2 it's polarity or grounding. On UC1/DC1 it adds 'low voltage'. On AUY/TUY it also adds 'ignitor triac fault'. On AUH2/TUH2 it's only reverse polarity. Your model prefix determines the exact diagnosis.
Source
Trane 18-CD20D3-21 Installer's Guide, p.36
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