Error Code: EH 0b – Indoor Main Control Board and Display Board Communication Error

Error Code: EH 0b – Indoor Main Control Board and Display Board Communication Error

What this means:
The main indoor PCB is not receiving any signal from the display board. This may be caused by a damaged communication wire, a faulty display board, or a malfunctioning main PCBTS39.

Try this first (quick reset):

1. Turn off the system power completely.

2. Wait 2 minutes.

3. Turn the unit back on and check the display.

• If the error clears — the connection may have stabilized.

• If it remains — continue with the following checks.

Next steps (for technicians):

1. Check the communication wire between the display board and indoor PCB:

   • If loose or damaged → repair or replace.

2. Replace the display board

   • If wiring is good but no communication is restored.

3. If the problem persists after replacing the display board:

   • Replace the indoor main PCB.

What you might need:

• Communication wire

• Display board

• Indoor main PCB

Helpful tip:
Most EH 0b issues are resolved by checking or replacing the communication wire. The display board is usually at fault before the main PCB.

Click here to view the detailed guide.TS39