About

This site lists furnace error codes and what they mean, taken from the manufacturers' installation and service manuals. Each code page links to the manual it came from.

We only publish codes we could check against a manual. If we could not read or confirm a code, we left it out.

This is general information, not professional advice. Gas furnaces can be dangerous. If you smell gas, leave the building and call your gas utility. For anything beyond basic checks, call a licensed HVAC technician.

Found a mistake? Check the linked manual for your exact model; manuals vary by model and revision.