E240
Low flame current — run mode
This code typically points to
- Dirty or weak flame sensor
- Poor neutral-to-ground reference
Next checks to confirm
- Use control diagnostics or field-installed mode to read flame current in microamps
- Clean or replace sensor
- Measure neutral-to-ground voltage to verify grounding
Escalation
Alert
Reset behavior
Clears after current heat call completes.
Service Soon
Schedule repair