Goodman furnace: Reversed 115V Polarity or Poor Ground
Professional repair
Why is the light on my Goodman furnace flashing continuously? Official: the 115-volt line polarity is reversed or the unit ground is poor. The furnace won't heat until wiring is corrected.
Line-voltage wiring — electrician or HVAC tech.
What causes it (in order of likelihood)
- Hot/neutral reversed at the furnace or outlet TECH
- Poor unit ground TECH
Parts for this code
No specific part number is verified for this code — it typically points at wiring, power, a blown fuse, or communication between components rather than one standard replacement part. If your diagnosis does land on a replaceable component, match its part number against your model's parts list before ordering.
Applies to
GMS8 · GDS8 · GHS8 · GMSS96 · GMH8 · GDH8
Different Goodman generations use different code maps. If your series isn't listed, don't assume this meaning — check your blower-door label.
Verified against Goodman GMS8/GDS8/GHS8 Service Manual (RS6612006), p.44 — “CONTINUOUS / Polarity of 115 volt AC / Poor unit ground”
Last verified 2026-07-06 · how we verify
Related Goodman fault codes
These codes use the same single red led — flash codes system.
| Pattern | Meaning |
|---|---|
| Igniter Circuit Fault or Poor Ground | |
| Low Flame Sense Signal | |
| Open Rollout Limit Switch | |
| Flame Sensed With No Call for Heat |