Cold but weak airflow

A Clementi customer noticed their bedroom aircon was still cold, but airflow kept getting weaker over 2 months. A contractor recommended replacing the indoor fan motor, saying it was wearing out. The customer wasn't convinced because the fan was still spinning. If airflow is weak but the fan still runs, get a WhatsApp second opinion before approving motor replacement.

What the customer told us

  • Unit: 6-year-old Mitsubishi wall-mounted, master bedroom
  • Symptom: Cold air, but airflow progressively weaker over 2 months
  • History: Servicing done 8 months ago, filter cleaned then
  • Pattern: Gets slightly worse each week, but fan still visibly spinning
  • Previous contractor's diagnosis: 'Fan motor bearings worn - replace motor'

What we assessed

Weak airflow with a visibly spinning fan usually isn't motor failure - motors tend to fail completely, not gradually. We checked for obstructions first, then assessed the motor's actual condition.

We found it:

  • Opened indoor unit: Fan blades coated in thick dust/lint despite 'cleaned' filter
  • Checked filter: Filter clean, but dust buildup behind filter on evaporator coil and fan barrel
  • Motor behavior looked normal during operation
  • No signs of bearing drag during manual rotation

Why this happened

The filter catches most dust, but fine particles still get through and accumulate on the evaporator coil and fan blades over time. As the buildup grows, it adds weight to the fan and restricts airflow through the coil. The motor was working fine, but it was pushing air through an increasingly clogged system. Cleaning the filter doesn't remove this internal buildup - it requires disassembly and chemical wash.

Fan motor replacement

INITIAL RECOMMENDATION

Major part swap suggested

Chemical wash

ACTUAL REPAIR PATH

Buildup removed first

Parts swap to cleaning

SCOPE SHIFT

After verification steps

5 months

RUNNING SINCE FIX

Original motor still fine

What we advised

Do a chemical overhaul to disassemble the indoor unit, remove dust buildup from the fan blades and evaporator coil, and reassemble. If airflow is still weak after cleaning, then check motor performance. Cleaning buildup first is the logical step before replacing a motor that is still running.

Band-aid approach

Approach

Replace fan motor

Timeline

Parts ordering + installation

Cost

Higher-cost parts replacement

Permanent fix

Approach

Chemical overhaul cleaning

Timeline

Same day service

Cost

Lower-cost cleaning after verification

What happened

Customer chose the chemical wash. We removed significant dust buildup from the fan barrel and coil fins. After reassembly and test run, airflow returned to normal strength. Temperature drop measured correctly. The original motor is still running fine 5 months later.

7 months ago

Customer noticed airflow getting gradually weaker

5 months ago (Week 1)

Airflow noticeably reduced, contacted previous contractor

5 months ago (Week 1)

Contractor recommended fan motor replacement

5 months ago (Week 2)

Customer contacted Snowflake for second opinion

5 months ago (Week 2, same day)

Snowflake assessment: Motor running fine, heavy dust buildup on fan and coil

5 months ago (Week 2)

Chemical overhaul completed, airflow restored to normal

Present

5 months later - airflow still strong, motor still original

What this shows

Why assessment matters

Weak airflow from a running fan is usually obstruction or buildup, not motor failure. Without verification, recommendations can move too quickly to replacement. The previous contractor saw 'weak airflow' and jumped to 'motor replacement' without checking if the motor was actually faulty. They moved to replacement before ruling out buildup.

What we do differently

We verify motor behavior and check for buildup before recommending parts. We look for simpler causes first, then escalate only when needed. Assessment means confirming what's broken, not guessing. If recommendations escalate quickly, send your findings on WhatsApp and we will map one clear next step.

Having a similar issue?

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