How we verify
The problem with furnace code tables online
Most "Goodman error codes" pages publish one generic table for the whole brand. But control boards change between generations — we documented cases where the same flash count means opposite things on two furnaces sold under the same brand (on one platform a single flash is an ignition lockout; on a newer one it means flame detected when there should be none — nearly the opposite severity). A generic table isn't just unhelpful, it can point you at the wrong repair.
Our process
- Source the manufacturer's service manual (not the marketing spec sheet) for each model series.
- Extract the diagnostic tables and cross-check the wording against a second official document where available.
- Bind every code to the exact series list from the manual — codes never "inherit" across generations.
- Cite the document and page on every code page, with the original wording quoted where it matters.
- Codes that fail verification don't ship. (Example: a widely-copied "9 flashes" definition appears in none of the three official manuals we checked — so we don't publish it.)
About repair quotes
When a code needs a professional, we link to quote services and may earn a referral fee. Diagnosis content is written first, from the manuals; monetization never decides what a code means or whether we tell you a $10 DIY part will fix it.
Corrections
Found a discrepancy against your unit's label? The panel label wins — and we want to know: [email protected].