LG · Oven
LG Oven F19 Error Code
Extended no-heat fault during preheat
What this error means
F19 covers oven no-heat cases where temperature failed to rise at least 10°F above starting temp within five minutes, or stayed at or below 100°F during preheat—excluding proof and warm modes on many firmware versions.
How F19 is detected
When F19 appears on a LG oven, the control board has confirmed that water did not leave the machine within the programmed drain window. On LG LREL6325F, LG LRG4113ST, and similar variants, the drain pump runs for a fixed interval—often three to seven minutes on washers and dishwashers—while a pressure switch or turbidity sensor verifies the tub or sump is empty. If water remains, the cycle stops to prevent spin with a full tub or overflow on the next fill.
Most F19 calls are resolved without parts: verify the oven door closes flush—no rack sticking out. Restricted drain paths mimic pump failure because the impeller spins against a blocked hose or filter. Document whether the pump hums audibly during the drain step; a humming pump with no water movement points to a clogged filter or kinked hose, while silence may indicate a failed pump motor or loose wiring at the harness.
After clearing blockages, run a short cycle and listen at the drain hose for steady water flow. If F19 returns on the next load with a clean filter and straight hose, measure resistance at the pump motor connector per the service manual for your model before ordering a replacement pump assembly.
Common causes
- Same root failures as F9 but more sensitive timing thresholds
- Door not fully latched letting heat escape
- Failed cooling fan not moving air in convection models
- Thermal fuse opened after prior overheating
Step-by-step fixes
- 1Verify the oven door closes flush—no rack sticking out
- 2Run standard Bake, not convection, for the first test after reset
- 3Breaker reset five minutes before retry
- 4Listen for convection fan at preheat start on fan-assisted models
When to call a technician
F19 with verified door closure needs heating circuit diagnosis identical to F9 service path.
Affected models
- LG LREL6325F
- LG LRG4113ST
- LG LDG4315ST
Prevention & maintenance
- Clean drain filters and hose terminations monthly on high-use ovens to prevent F19 from lint and food debris buildup.
- Record when F19 appears in the cycle and whether it clears after a 60-second power reset on your LG oven—that detail speeds diagnosis if you call service.
- Keep the model and serial number from the rating plate when ordering parts for F19; LG uses multiple revisions with different harness lengths and board firmware.
- Photograph wiring connector orientation before disconnecting any component while troubleshooting F19; reversed plugs on pumps and valves cause immediate repeat faults.