General Air Conditioning | Technical Service Bulletin

Crossflow Fan Contact Noise

Wall-mounted indoor units – KM and KG series
Safety requirement: Stop the air conditioner and isolate the electrical power supply before opening the unit or adjusting the crossflow fan. Reconnect power only when the unit is ready for the final operational test.
Applicable products: Fujitsu wall-mounted indoor units from the KM and KG series. Confirm the exact model and construction before carrying out the adjustment.

1. Overview

Following transportation or handling, the crossflow fan may move slightly towards the left side of the indoor unit. If the fan shifts far enough, it can contact the adjacent base assembly or surrounding components while operating.

This contact may produce a repetitive rubbing, ticking, scraping or rotational noise from the left-hand side of the indoor unit.

ItemDetails
Likely causeCrossflow fan displaced towards the left during transport or handling.
Typical contact areaLeft-hand end of the crossflow fan contacting the base assembly or an adjacent stationary component.
Corrective actionLoosen the fan fixing screw, reposition the crossflow fan approximately 2 mm to the right, retighten and test.

2. Confirm the Symptom

  1. Operate the indoor unit and identify whether the noise is rotational and coming from the left-hand side.
  2. Confirm that the noise changes with indoor fan speed.
  3. Stop operation and isolate the electrical supply.
  4. Visually inspect for signs of contact between the left end of the crossflow fan and the surrounding base assembly.
Do not continue with this adjustment if the fan is cracked, distorted, missing blades, heavily contaminated or has excessive bearing movement. Those conditions require further repair or component replacement.

3. Crossflow Fan Adjustment Procedure

Step 1 – Access the crossflow fan

Open the outlet louvre. Insert a suitable cross-head screwdriver through the gap in the fan guard.

Ensure the screwdriver is positioned carefully so the louvre, fan guard and crossflow fan blades are not damaged.

Step 2 – Locate the service access position

Using the screwdriver only as a turning aid, slowly rotate the crossflow fan by hand.

Locate the service access opening at the right-hand end of the crossflow fan where there is no fan blade. This opening provides access to the fan fixing screw.

Caution: Do not lever against, bend or force the crossflow fan blades. Damage to the blades can create imbalance, vibration and additional noise.
Step 3 – Loosen the fan fixing screw

Insert the cross-head screwdriver through the service access opening and engage the fan fixing screw.

Turn the screw anticlockwise approximately one turn. Do not fully remove the screw.

Step 4 – Reposition the crossflow fan

Move the crossflow fan approximately 2 mm to the right, or only far enough to provide clearance from the contact point.

Confirm the fan remains centred, rotates freely and does not contact another component at the opposite end.

Step 5 – Retighten the fixing screw

Hold the fan in its corrected position and tighten the fan fixing screw securely.

Rotate the crossflow fan by hand through several full revolutions and confirm that it moves freely without rubbing or binding.

4. Final Verification

CheckVerification requirement
1Remove all tools and confirm the louvre and fan guard are correctly positioned.
2Reconnect the electrical supply.
3Run the indoor fan at low, medium and high speed.
4Confirm the original contact noise is no longer present.
5Confirm there is no new vibration, imbalance, scraping or movement of the fan.
Successful outcome: The crossflow fan rotates freely at all fan speeds with no contact noise, scraping or abnormal vibration.
If the noise remains: Re-isolate the power and inspect the fan position, fixing screw, motor shaft, left-hand bearing, fan guard, base assembly and fan condition. Do not repeatedly shift the fan without confirming the actual contact point.

5. Service Record

Record the following information in the service report:

  • Indoor unit model and serial number
  • Location and description of the original noise
  • Whether crossflow fan contact was confirmed
  • Approximate adjustment completed
  • Final test result at each fan speed
Reference: Fujitsu General Service Bulletin RAC-0090-02, issued 17 December 2019. Always confirm current technical information and model applicability before completing service work.