Complete Aircond Chemical Overhaul - Deep Clean Every Component!

What Is a Chemical Overhaul?

A chemical overhaul is the most intensive and thorough aircond cleaning service available. While a standard chemical wash cleans the unit while it remains mounted on the wall, a chemical overhaul takes things to a completely different level.

During a chemical overhaul, the refrigerant gas is first safely recovered through a pump down procedure. The entire indoor unit is then removed from the wall bracket, giving our technicians unrestricted access to every single component. Each part — the evaporator coil, blower wheel, fan blades, drainage pan, unit housing, and filters — is individually removed, soaked in professional-grade alkaline chemical solution, and meticulously cleaned.

This is the service for aircond units that have been seriously neglected, are heavily contaminated with mould, or have persistent problems that a regular chemical wash could not fully resolve.

Chemical Overhaul vs Chemical Wash — What Is the Difference?

This is one of the most common questions we get from homeowners across PJ and KL. Here is a clear comparison:

Chemical Wash (from RM160)

• Unit stays mounted on the wall during cleaning
• Front panel, filters, blower wheel, and drainage pan are removed
• Evaporator coil is cleaned in place with chemical solution
• Drainage pipes are flushed
• Includes FREE gas top-up
• Takes about 45 minutes to 1 hour per unit
• Recommended every 6 to 12 months for regular maintenance

Chemical Overhaul (from RM280)

• Refrigerant gas is pumped down first
• Entire indoor unit is removed from the wall bracket
• Every component is individually removed, soaked, and cleaned
• The unit housing itself is cleaned inside and out
• Full gas recharge after reassembly
• Takes 2 to 3 hours per unit
• Recommended for severely neglected units or units with heavy mould

The key difference is access. When the unit stays on the wall during a chemical wash, there are parts of the evaporator coil and housing that simply cannot be reached effectively. A chemical overhaul eliminates this limitation entirely because the unit is completely dismantled off the wall. For a more detailed comparison, read our guide on chemical wash vs chemical overhaul.

When Do You Need a Chemical Overhaul?

Not every aircond needs a chemical overhaul. For most units that receive regular maintenance, a chemical wash every 6 to 12 months is perfectly sufficient. However, there are specific situations where a chemical overhaul is the right call:

Your aircond has not been serviced in over 2 years. After two or more years without maintenance, the internal components accumulate layers of hardened grime, grease, and biological growth that a standard chemical wash may not fully remove.

Persistent foul odours even after a chemical wash. If you had a chemical wash done recently but the musty or sour smell came back within a few weeks, it means there is deep-seated mould or bacteria in areas that could not be reached with the unit on the wall.

Visible mould growth on or around the unit. If you can see black or green mould spots around the air vents or on the front panel, the contamination has likely spread deep into the evaporator coil and housing. A chemical overhaul is the only way to fully eliminate it.

Your aircond still does not cool properly after a chemical wash. Sometimes the evaporator coil is so clogged that an in-place chemical wash cannot restore full performance. Removing the unit allows for a more thorough and effective clean.

You want to extend the life of an older unit. If your aircond is 5 to 10 years old but the compressor is still healthy, a chemical overhaul can restore it to near-original performance and extend its useful life by several years — saving you the cost of a full replacement.

Our Chemical Overhaul Process

Our chemical overhaul process has been refined over 20+ years of servicing thousands of units across Petaling Jaya, Kuala Lumpur, and the wider Klang Valley.

Step 1 — Preparation and Assessment

Our senior technician inspects the unit to confirm that a chemical overhaul is the appropriate service. We check the compressor health, refrigerant levels, and overall condition. Protective sheets are laid to protect your walls, floor, and furniture.

Step 2 — Refrigerant Pump Down

The refrigerant gas (R22, R32, or R410A) is safely recovered into the outdoor unit through a controlled pump down procedure. This ensures no gas is lost during the process and the system can be disconnected safely.

Step 3 — Complete Unit Removal

The indoor unit is disconnected from the copper piping, drainage, and electrical connections. The unit is then carefully lifted off the wall bracket. This gives our technicians complete, unrestricted access to every component.

Step 4 — Full Disassembly

The indoor unit is taken apart piece by piece. The evaporator coil, blower wheel, fan blades, drainage pan, filters, and housing are all separated for individual attention.

Step 5 — Individual Chemical Cleaning

Each component is soaked in professional-grade alkaline chemical solution. Stubborn deposits are removed with careful brushing and high-pressure water jets. The evaporator coil receives special attention — it is soaked, flushed, and rinsed until it is restored to near-original cleanliness. Mould, bacteria, and organic buildup are completely eliminated.

Step 6 — Drainage System Overhaul

The drainage pan, drain pipe, and all water channels are thoroughly cleaned and tested. Blockages are cleared, cracks are identified, and the entire drainage pathway is verified to be flowing freely.

Step 7 — Reassembly and Remounting

All cleaned components are reassembled and the indoor unit is remounted on the wall bracket. Copper piping, drainage, and electrical connections are reattached and checked for secure fit.

Step 8 — Gas Recharge and Testing

The refrigerant system is vacuumed and recharged with the appropriate gas. The unit is then run for at least 20 minutes while our technician monitors temperature output, checks PSI readings, listens for unusual sounds, and inspects all connections for leaks.

Brands We Service

Our senior technicians perform chemical overhauls on all major aircond brands available in Malaysia, including:

• Daikin — wall-mounted, ceiling cassette, and multi-split systems
• Panasonic — standard and inverter models
• York — residential and light commercial units
• Acson — a popular choice across Malaysian homes
• Mitsubishi — premium residential and commercial systems
• Samsung, LG, Midea, and Haier

We are experienced with both inverter and non-inverter technology, and our technicians understand the specific handling requirements of each brand.

Why Choose PJ Kool for Chemical Overhaul

Advanced skill required — and we have it. A chemical overhaul involves refrigerant handling, complete unit removal, and precision reassembly. This is not a job for beginners. Our senior technicians — Mr. Heng, Ahmad, and Raju — have each performed hundreds of overhauls and bring 15 to 20+ years of individual experience.

Save thousands versus replacement. A new aircond unit plus installation can cost RM2,000 to RM5,000 or more. If your existing unit’s compressor is still healthy, a chemical overhaul at a fraction of the cost can restore it to peak performance and extend its lifespan by years.

Transparent quoting with no hidden fees. We will assess your unit and give you a clear price before we start. No surprise charges for transport, parking, or “extra work discovered during the job.” The price we agree on is the price you pay.

Serving all of PJ, KL, and Klang Valley. We provide chemical overhaul services in Petaling Jaya, Damansara Jaya, Damansara Utama, Kota Damansara, Bandar Utama, Subang Jaya, Kelana Jaya, Puchong, and beyond.

Think your aircond needs a chemical overhaul? WhatsApp us at 012-2252 623 — we will help you decide whether an overhaul or a chemical wash is the right service for your unit.