BGH BSBSIC24CTK Manual page 40

Troubleshooting
2. E2 malfunction
Communication malfunction between indoor IC and outdoor IC
Judge 1: Check whether the indoor unit power is on
Judge 2: Check whether the signal wiring is shield cable or whether
the shield cable is earthed
Judge 3: Check whether the signal wiring between the indoor and
outdoor units is wrong polarity?
Judge 4: Check whether the signal wiring between the indoor and
outdoor units is broken?
Indoor or outdoor main board is broken. Replace the main
board until the malfunction disappears.
3 6
E2 display
Yes
Yes
No
No
No
Turn on the indoor unit power
No
Adopt the shield cable/ let shield cable earthed
Yes
Connect the signal wiring correctly
Yes
Replace the broken wiring