Why does my aircon smell bad?

 

Aircon Repair 

A properly functioning air conditioning system should cool your home or office quietly and cleanly. But if your aircon starts emitting a foul smell, it can turn comfort into discomfort. Many Singapore homeowners and business owners have experienced this issue—whether it’s a musty odour, burning smell, or a sour, unpleasant stench. But what causes these aircon smells, and how can you fix them?

At Letscool Aircon and Services, we’ve helped thousands of customers resolve aircon odour problems with expert diagnosis and professional servicing. In this article, we explain the common reasons your aircon might smell bad, what each type of smell means, and how you can prevent it from happening again. View more. 

Common Types of Aircon Smells and What They Mean

1. Musty or Mouldy Smell

This is the most common aircon odour and often smells like damp socks or stagnant water.

Cause:
Mould or mildew buildup inside the unit—typically on the evaporator coils, filters, or in the drainage system due to trapped moisture and poor maintenance.

Solution:
A thorough chemical wash or chemical overhaul is usually required to remove the microbial growth and disinfect internal parts. At Letscool, our technicians clean all components, including filters, coils, and drainage pans, to eliminate odours at the source.

2. Rotten or Sour Smell

A strong, foul odour that smells like something has decayed inside the unit.

Cause:
Dead insects or small animals like lizards may have gotten trapped inside the aircon unit or ducts. In some cases, it may be the result of stagnant water mixed with dust, leading to bacterial growth.

Solution:
Professional dismantling and cleaning of the indoor unit are needed to remove any foreign matter. Letscool technicians can safely identify and clean out the unit while disinfecting it to prevent recurring odours.

3. Burning or Electrical Smell

This odour is sharp and smells like burning plastic or wiring.

Cause:
Overheating components such as wiring, motors, or circuit boards can cause this smell. It may indicate a serious electrical fault or motor failure.

Solution:
Turn off your unit immediately and call a technician. Continuing to use the aircon can pose a fire risk. At Letscool, we offer fast emergency response to inspect and repair electrical faults.

4. Chemical or Paint-Like Smell

Some aircon units may emit a chemical-like or solvent smell during operation.

Cause:
Refrigerant gas leaks or issues with newly installed or poorly cleaned units. Sometimes, it may be due to chemical reactions between indoor pollutants and ozone from electrical components.

Solution:
Gas leak detection and repair must be carried out. Letscool team can identify refrigerant leaks using advanced tools and top up or repair the gas system safely.

5. Cigarette or Smoke Smell

Even if no one is smoking near the aircon, you may notice a smoky or stale cigarette smell.

Cause:
This usually happens in rooms where people previously smoked, and the odour is trapped in the filters or ducts. It may also be pulled in from nearby apartments or buildings.

Solution:
Filter and duct cleaning is necessary. Letscool can deodorize and sanitize your system using air-purifying solutions.

Why Aircon Smells Are Common in Singapore

Due to Singapore’s humid climate, air conditioning systems often retain moisture. When this moisture isn't removed properly—either due to clogged filters, blocked drainage, or infrequent servicing—it becomes a breeding ground for mould and bacteria. Over time, this results in unpleasant smells that are blown into your room when the aircon is turned on.

How to Prevent Bad Aircon Smells

✅ 1. Regular Servicing

Schedule professional aircon servicing every 3 to 6 months, depending on usage. Routine maintenance helps prevent microbial buildup, removes dust, and ensures smooth airflow.

Letscool Tip: Sign up for our affordable contract servicing plans for peace of mind and long-term savings.

✅ 2. Chemical Wash or Overhaul

If your unit hasn’t been cleaned deeply in a while, opt for a chemical wash or overhaul. This service dismantles key parts and cleans them thoroughly with chemical solutions.

Letscool Benefit: We offer reliable chemical overhaul services with a 90-day workmanship warranty to ensure your aircon stays clean and odour-free.

✅ 3. Replace or Clean Filters Frequently

Dirty filters trap odours, dust, and bacteria. Clean them every month and replace them when needed.

 4. Check for Leaks and Drain Blockages

Ensure that drainage pipes are not clogged and that water flows freely out of the unit. Stagnant water is a major cause of smells.

✅ 5. Use an Air Purifier or UV Lamp Add-On

Some advanced systems allow you to install UV sterilizers or air purification add-ons that kill bacteria and remove odours.

Why Choose Letscool Aircon and Services?

At Letscool Aircon and Services Singapore, we bring over 25 years of hands-on experience in diagnosing and resolving aircon problems, including persistent odour issues. Our qualified technicians work with all major brands—Mitsubishi Electric, Daikin, Panasonic, Midea, and more.

With Letscool, you’ll enjoy:

• Expert diagnosis and full inspection
  
  

• Fast and effective odour removal
  
  

• Chemical wash and overhaul services
  
  

• Transparent pricing and professional support
  
  

• 90-day workmanship warranty for added assurance
  
  

• Free on-site surveys for aircon installation or servicing
  
  

Final Thoughts

A smelly aircon is more than just a nuisance—it’s a sign that your unit needs professional attention. Whether it’s mould, bacteria, gas leaks, or mechanical issues, ignoring the problem can lead to poor air quality, health concerns, or even system damage.

Let the experts at Letscool Aircon and Services help you restore fresh, clean air to your home or office. We offer quick response times, expert service, and a commitment to customer satisfaction across Singapore.

Experiencing bad smells from your aircon?
📞 Call +65 9862 3678 today for expert servicing or a free consultation.
Let Letscool Aircon and Services Singapore bring back the cool, fresh air you deserve.

11 Mandai Estate,

 #05-15 Eldix,

Singapore 729908

Mail ID: info@letscoolaircon.com.sg

Call: +65 9862 3678  (or) WhatsApp us: https://wa.me/6598623678

#AirconRepair #AirconrepairServices #SingaporeAirconRepair #acrepair #airconrepairservicesingapore #acrepairservicesingapore #airconrepairservicing #airconrepairservice #airconservicenearme #airconservicingnearme #commercialairconservice  #commercialairconservicing #commercialacservicing #airconcommercialservice #airconservice #airconservicing #airconservicecompany #airconservicesingapore #airconservicingsingapore #bestairconservice #bestairconsingapore #airconcleaningservice #airconcleaning #acservice #acservicing #acservicesingapore #acservicingsingapore #AirconRepair #AirconMaintenance #SingaporeAirconService  #letscoolaircon #airconservicenearme #airconservicingnearme #airconcleaning #airconcleaningservice