5 amber flashes
Reduced heating capacity from combustion-air/vent restriction or clogged condensate drain
This code typically points to
- Combustion air restriction
- Vent restriction
- Clogged condensate drain
Next checks to confirm
- Inspect vent and combustion air
- Verify condensate drain flow
- Measure inducer draft
Escalation
Persistent condition may trigger pressure-switch fault.
Reset behavior
Clears when vent/condensate is restored.
Service Soon
Schedule repair