Indoor/Outdoor Unit Communication Error (Indoor Receiving)
Mitsubishi Electric · PUZ-HA30/36NHA4 Outdoor Unit
What does E6 (6810) mean?
The indoor controller board fails to receive any signal normally for 6 minutes after power-on, or for 10 minutes, or if 2 or more indoor units are connected to an outdoor unit and the indoor controller board doesn't receive a signal for 10 minutes allowing outdoor transmission. Potential causes include contact failure, short circuit, or miswiring of the indoor/outdoor unit connecting wire, defective transmitting/receiving circuits (outdoor controller, indoor controller), noise, a defective fan motor, or a defective rush current resistor. Another indoor controller board in a twin system may also be faulty.
Common Causes
- Indoor unit fails to receive communication signals from the outdoor unit.
- Damaged or disconnected communication wiring.
- Faulty indoor unit control board.
- Interference on the communication line.
Repair Steps & Checklist
Click steps to track your progress.
- 1
Check for disconnection or looseness, short circuit, or miswiring of the indoor/outdoor unit connecting wire on indoor and outdoor units. For twin indoor unit systems, check all units.
- 2
Turn the power off, then on again. If abnormality generates again, replace the indoor controller board or outdoor controller circuit board.
- 3
Turn the power off, detach the fan motor from connector (CNF1, 3). Then turn the power on again. If abnormality is not displayed, replace the fan motor. If abnormality is displayed, replace the outdoor controller circuit board.
- 4
Check RS1 on the outdoor noise filter board with a tester. If an open circuit is detected, replace the board.
- 5
If a twin indoor unit system is in place, check the LED display on the outdoor controller circuit board using the PAC-SG610ST A-Control service tool. Refer to EA~EC item troubleshooting if displayed.