E115
Low 24V — control will restart if error recovers
This code typically points to
- 24V outside Lennox's stated 18 to 30 VAC range
- Too much power-robbing load on system
Next checks to confirm
- Measure low-voltage supply
- Check for added loads
- Increase transformer VA if needed
Escalation
Restart if error recovers
Reset behavior
Clears after fault recovers.
Service Soon
Schedule repair