KGHV Dominator Series – “Inner and Outer Board Communication” or “E6” Fault

Possible Safety Float Triggered by a Full Water Tray

Overview

The “inner and outer board communication” fault (shown as E6 on XE71 or “inner and outer board com” on LE60) typically indicates a communication issue between indoor and outdoor PCBs. However, this fault may also be triggered by the safety float switch due to a full condensate tray, especially during cooling mode.

Common Causes

  • Blocked Drain: Ensure the drainpipe is clear and unobstructed.
  • Low Airflow Settings:
    • May have been set too low during commissioning.
    • Can lead to excess condensate overwhelming the drainage system.
  • Pump Issues:
    • Debris blocking the impeller.
    • Bent pump bracket causing inlet to bottom out.
    • Pump clearance should be 5mm above tray base.
  • Float Switch Mounting:
    • Should be mounted 8–10mm above tray base.
    • Incorrect mounting may cause premature triggering.

Important Note

There is no user reset for this fault. Once the float switch is triggered, the system locks out the indoor fan and condensate pump. Recovery requires manual intervention or waiting for water to evaporate, which may take hours or days.

Technician Steps to Clear / Reset Fault

  1. Remove Access Panel to Pump.
  2. Manually hold float switch down to clear fault.
  3. Run unit in Fan-Only mode to activate drain pump.
  4. Verify pump operation:
    • Confirm water evacuation.
    • Check for proper flow and no obstructions.
  5. Release float switch and refit access panel.

Service Field Update – Float Switch Bracket

Refer to the KGHV-04-A Service SOP for bracket replacement:


Additional Tips

  • Routine Maintenance:
    • Clean tray and pump inlet.
    • Check and clear drainpipe.
    • Inspect float switch and pump mounting.
  • Fan Tuning:
    • Ensure airflow settings are appropriate to prevent excess condensation.

Visual Indicators

  • LE60 / XE71 Display: “inner and outer board com” or E6
  • System Behavior:
    • Indoor fan and condensate pump stop.
    • Float switch remains triggered until manually reset.

 

Float Switch Bracket Update


Error code on LE60 equal to E6, communication between indoor and outdoor boards


Debris blocking pump impellor


Debris built up in drain tray


Drain tray filled up with water and not draining away