Aircon Chemical Wash in Singapore - Restore Cooling and Air Quality

Why Regular Servicing Can’t Clear Mould and Biofilm

A basic aircon servicing cleans the filter, wipes down the cover, and sprays a mild cleaning chemical on the visible coil. That’s fine as quarterly maintenance. But when mould has colonised the drip tray, when slime has grown thick enough to block the drainage pipe, or when the blower wheel is so coated in dust that airflow has dropped by half, no amount of surface-level cleaning will recover the unit.

A chemical overhaul is the reset. We dismantle the indoor unit down to its component parts, soak them in a carefully calibrated chemical solution, and rebuild the unit from clean metal outwards. For heavy-use Singapore homes — or any unit over 5 years old that’s never been overhauled — this is the service that makes the difference between a unit you replace in 2 years and one that lasts another 6.

What a Coolbest chemical overhaul covers

Every chemical overhaul job follows the same sequence. We set up drop sheets on your floor before any tool touches the unit, and we keep the workspace tidy as we go — because a clean service on a dirty floor is a failed service.

• Dismantle the indoor unit fascia, remove the fan coil, detach the blower wheel, and take down the drainage pan
• Pre-rinse loose dust and debris before chemical application
• Soak fan coil, blower wheel, and drainage components in our calibrated cleaning solution
• Scrub the blower wheel blades manually — this is where airflow loss usually hides
• High-pressure water jet the evaporator coil to strip bacterial biofilm and remaining residue
• Desludge the drainage tray and flush the drain pipe to clear any slime blockage
• Inspect the fan motor bearings, thermistor placement, and control PCB for heat or moisture damage
• Reassemble with fresh insulation on any worn sections and apply corrosion protection to exposed metal joints
• Test the unit through a full cooling cycle before we leave

When an overhaul is the right call

Not every unit needs a chemical overhaul. Our technicians will tell you if a standard service is enough. We’d rather sell you the smaller job and see you again next time than oversell once and lose your trust.

Signs your unit probably needs an overhaul:

• Sour, mouldy, or musty smell when the aircon runs (typically mould spores circulating through the fan coil unit)
• Water dripping from the front of the unit (drainage blockage from jelly-like slime buildup)
• Cooling has dropped noticeably over the past 3–6 months despite regular servicing
• Unit is 5+ years old and has never had a chemical overhaul
• Visible black slime inside the drainage tray or around the coil
• Dust blowing out of the vents when the fan starts

If you’re not sure, send us a photo or a 10-second video of the unit over WhatsApp and we’ll tell you honestly whether overhaul or standard service is the right call.

Pricing & warranty

Our chemical overhaul starts from S$90 per indoor unit after inspection. The final quote depends on unit size, whether we need to include the outdoor unit, and how much the drainage system has clogged. We never start work before confirming the quote with you in writing (usually via WhatsApp).

Every overhaul comes with a 90-day workmanship warranty. If the unit develops a drainage leak, a rattling blower, or any fault related to our work within 90 days, we come back and fix it free. That’s the Coolbest promise — and after 18 years across Singapore, it’s still the simplest way we know to keep neighbours coming back.

Ready to book?

WhatsApp us a photo of your unit and your postcode. We’ll reply within the hour during working hours with a timing slot and an honest quote — and if standard servicing would be enough, we’ll tell you that instead.