Goodman furnace 7 flashes: Low Flame Sense Signal
DIY-friendly fix
What does 7 flashes mean on a Goodman furnace? The furnace keeps running, but the flame sensor's microamp signal has dropped below spec — a warning before ignition lockouts start. Official: coated/oxidized sensor, a badly positioned sensor, or a lazy flame from poor gas pressure.
Before you touch anything: the six signs that mean stop troubleshooting and call a pro →
GOOD NEWS: THE FIRST CHECKS ARE FREE AND TAKE MINUTES.
Try these first — in this order
Clean or replace the flame sensor — 15 minutes, very high success rate.
If it returns after cleaning, gas pressure needs professional adjustment. DIY part cost: $8–15 — a pro visit for this class of fault typically runs $150–350.
What causes it (in order of likelihood)
- Coated or oxidized flame sensor (official first cause) DIY-CHECKABLE
- Sensor positioned out of the flame TECH
- Improper gas pressure or combustion air TECH
Parts referenced by this code
Always match parts against your model's parts list — part numbers vary within a series.
Questions about this code
What does 7 flashes mean on a Goodman furnace?
The furnace keeps running, but the flame sensor's microamp signal has dropped below spec — a warning before ignition lockouts start. Official: coated/oxidized sensor, a badly positioned sensor, or a lazy flame from poor gas pressure.
How do I fix Goodman furnace 7 flashes?
Note whether it keeps heating normally. Cleaning or repositioning the sensor and checking gas pressure or combustion air involve the burner area, so schedule a technician before ignition lockouts start.
How much does it cost to fix Goodman furnace 7 flashes?
Cost depends on whether the sensor needs cleaning, repositioning, or replacement, or whether gas pressure or combustion air needs adjustment. Ask the technician which problem they found before agreeing to a repair.
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 GMSS96 Service Manual, p.33 — “seven flashes followed by a pause”
Verified against Goodman GMS8/GDS8/GHS8 Service Manual (RS6612006), p.44/46 — “7 FLASHES”
Last verified 2026-07-06 · page updated 2026-10-03 · how we verify
Related Goodman furnace codes
These codes use the same single red led — flash codes system.
| Pattern | Meaning |
|---|---|
| 6 flashes | Open Rollout Limit Switch |
| 8 flashes | Igniter Circuit Fault or Poor Ground |
| 5 flashes | Flame Sensed With No Call for Heat |
| rapid flashing | Reversed 115V Polarity or Poor Ground |