What does Rheem code 13 mean?
Rheem furnace code 13 means the flame signal was lost while the burners were operating on the supported control family. Confirm the model number and diagnostic chart inside the furnace door before replacing parts.
What causes Rheem code 13?
- A dirty or weak flame sensor
- Unstable gas pressure or burner flame
- Poor grounding or flame-sensor wiring
Can I troubleshoot Rheem code 13?
- Confirm the gas shutoff has not been moved and the furnace panel is fully seated.
- Try one reset and watch whether the burners light and then shut off again.
How much does Rheem code 13 cost to fix?
A flame sensor cleaning or replacement typically costs between $100 and $600 nationally.
When should I call a technician?
Call a technician if flame drops out again or ignition becomes delayed or noisy.
Symptoms this code causes
Sources and model scope
Fault codes vary by model and control board. Confirm the diagnostic chart inside your furnace panel or the official manual before acting.
Scope used here: Rheem/Ruud RGFG-family controls using the documented two-digit diagnostic table.
- Rheem Manufacturing Company: RGFG Series Gas Furnace Installation Instructions and Diagnostic Codes
92-24161-104-06 · Rheem/Ruud RGFG-family furnace controls; confirm the unit model and its door chart before applying a code meaning.
Compiled by Warmlo Editorial · Reviewed August 2026
This is general information, not professional advice. Gas, electrical, and combustion repairs can be dangerous — when in doubt, call a licensed technician.