Full-Dismantle Chemical Overhaul: Rescue Neglected, Mouldy, or Leaking Units

What is a Full-Dismantle Chemical Overhaul?

The Full-Dismantle Chemical Overhaul is our deepest chemical wash service. We take the entire fan coil unit (FCU) off the wall, soak the evaporator coil and blower wheel in a chemical bath tray, deep clean the cover and drainage pan, inspect the insulation, apply anti-bacterial and anti-fungal treatment, then reassemble and pressure-check the gas before reading post-wash performance.

This is the right tier for units that regular servicing can no longer save. The chemical bath dissolves embedded biofilm and mould that an in-place flush can’t reach. It’s the right call when a unit has gone 6+ months without servicing, shows visible black mould, or keeps throwing foul smells, ice, or water leaks.

What’s Included

• ✓ Full fan coil dismantle with photo documentation
• ✓ Chemical bath soak-and-flush of coil and blower
• ✓ Cover and drainage pan deep clean
• ✓ Insulation inspection
• ✓ Anti-bacterial and anti-fungal treatment (99.9% kill rate)
• ✓ Reassembly, gas pressure check, performance reading
• ✓ Digital receipt and 90-day workmanship warranty

When You Need a Full-Dismantle Overhaul

Five hard indicators make this the right tier instead of a Non-Dismantle Chemical Wash:

1. Foul smell. A musty, sour, or sewage-like odour means biofilm has colonised the coil and drain pan past what a surface treatment can fix.
2. Ice on the evaporator coil. Restricted airflow from heavy build-up forces the refrigerant too low. Regular servicing won’t fix the underlying cause.
3. Water leaking inside. Sludge has blocked the drainage pan or condensate pipe, and in-place flushing usually can’t clear it.
4. Visible black mould on the fins or pan when the cover is off.
5. 6+ months unserviced. Biofilm has had time to embed deep in the coil. A chemical bath soak is the only way to reach it.

Not sure which tier you need? The Chemical Wash vs Chemical Overhaul guide walks through the symptom-based decision tree.

Why Direct Technicians Matter for Overhaul

Full-Dismantle is technically demanding work. Taking a fan coil unit off the wall means isolating power, detaching the control board safely, handling refrigerant lines without damaging flare nuts, removing the thermistor before any chemical exposure, and reassembling without trapping moisture in the insulation. Subcontractors paid per job have every reason to skip steps. We don’t subcontract. Every overhaul is done by our in-house BCA/NEA-compliant team, and every overhaul carries a 90-day workmanship warranty.

We work on all major Singapore aircon brands, including Daikin, Mitsubishi Electric (Starmex), Panasonic (Enviro), Toshiba, LG, and Fujitsu. The dismantle procedure and chemical bath soak work the same way across brands. What changes is the specific bracket configuration and drain pan design, which our technicians know by model.

Restoration Rate on “Needs Replacement” Units

We track our restoration rate carefully because it’s the central claim of our service. Across units other shops have written off as needing replacement, the Full-Dismantle Chemical Overhaul brings back roughly 100% of them, provided the compressor itself tests healthy during inspection. Coil, blower, drainage, and cooling performance can almost always come back to near-new with a proper chemical bath. Replacement is only the right answer when the compressor itself has genuinely failed.

Pricing

From S$130 for HDB and condo single-location units. Older or heavier-build-up units (typical Toa Payoh, AMK, and mature Bedok stock) may quote S$150 to S$180 after a pre-wash inspection. Either way, we always confirm the price up-front before starting.

Landed properties, CBD office buildings, and jobs starting after 6 PM carry an add-on charge that we quote in writing before we arrive. Gas top-up is a separate add-on, only added if the gas pressure check confirms the unit actually needs refrigerant.