24V activation failure.
Measures to take when alert occurs:
- Power source
- FNS control board (FNSCB)
- The message "Please call service" is displayed on the panel.
Solution:
- Confirm the connection from the main body to FS and if the power source is supplied. Repair it when there is any abnormality.
- Check FNSCB, and replace it when there is any abnormality.
