🌫️ Why Does My Aircon Smell Musty?

If you’ve turned on your aircon and noticed a damp or “old socks” smell, you’re not alone. A musty odour is one of the most common complaints from homeowners — and it’s often a sign that something inside your system needs attention.

In Singapore’s humid weather, your aircon constantly deals with moisture and condensation, which creates the perfect environment for mould and bacteria to grow. Here’s what causes the musty smell and what you can do to fix it.

1. Mould and Mildew in the Evaporator Coils

When moisture accumulates on your coils and isn’t drained properly, mould spores begin to grow. These spores produce the familiar musty smell every time you switch on the aircon.

Signs:

• The smell worsens after running the aircon for a few minutes

• Family members experience sneezing or sinus irritation

• You see black or grey spots inside the vents

Solution: A chemical wash or steam cleaning is needed to kill mould and remove residue from the evaporator coils and blower fan.

2. Clogged or Dirty Drain Pipe

Condensation naturally flows out through a drain pipe. But when it gets blocked by dirt or algae, stagnant water builds up inside — leading to bacteria growth and odours.

Solution: Have your drainage line vacuumed or flushed by a technician. Regular maintenance prevents this from recurring.

3. Dirty Air Filters

When filters are covered in dust, they trap humidity and encourage mould growth. Every time air passes through, the smell spreads throughout your home.

Solution: Clean your filters every 2–3 weeks. If the smell remains after cleaning, a chemical wash is the next step.

4. Full or Stagnant Drain Pan

Your drain pan collects condensed water before it drains away. If it becomes full or rusted, stagnant water creates a breeding ground for odour-causing bacteria.

Solution: During servicing, the drain pan should be drained, cleaned, or replaced if it’s corroded.

5. Poor Ventilation and Humidity

Sometimes, the problem isn’t with the aircon itself. In closed rooms, stale air and humidity can amplify odours from carpets, furniture, and even wall paint.

Solution: Open windows for a few minutes daily to refresh the air. For rooms without windows, use a dehumidifier.

How Sky Blue Aircon Can Help

At Sky Blue Aircon Engineering Pte Ltd, we specialise in identifying and eliminating musty aircon odours at the source.

Our Services Include:

• Regular Aircon Servicing – Cleaning filters, coils, and drain pipes to maintain fresh airflow.

• Chemical Wash – Deep cleaning that removes mould and bacterial buildup inside the unit.

• Drainage & Coil Maintenance – Ensuring proper condensation flow and coil hygiene.

• Odour Neutralising Treatment – Using safe, family-friendly cleaning agents.

💡 The Bottom Line

A musty smell means it’s time for maintenance — not just masking the odour with air fresheners. Cleaning your aircon regularly ensures clean, healthy air for your family and prevents costly breakdowns later on.

📲 Message us on WhatsApp at 9248 7291 or call 6556 4042.

Sky Blue Aircon Engineering Pte Ltd – keeping Singapore homes fresh, cool, and odour-free.