Can a chemical overhaul fix a Daikin aircon that is not cooling?
Yes, when the cause is dirt. A Daikin that is not cooling is often choked by mould deep in its coil and blower fan. An overhaul takes the unit down, washes every part with chemical and PowerJet, refits it and clears the pipes of air and moisture. It will not fix a gas leak or a failed part.
Key takeaways
- Dirt blocks the cooling: a coated coil cannot take heat out of the room air.
- The unit comes off the wall: coil, blower fan, drain pan and casing are washed separately.
- Gas is checked too: every overhaul includes a free gas check and top-up and a deep evacuation.
- A last resort for a very dirty unit: try a wash first; low gas or a faulty part needs a different fix.
In the video above, a first-time customer called us because their Daikin had stopped cooling. When we took the unit down and opened it up, the coil was black with mould. We applied coil chemical, rinsed it with our PowerJet, washed the other parts, reassembled the unit and put it back on the wall, where it cooled like new.
Does your Daikin need an overhaul?
- Wash the filters first. If they are clogged, clean them and run the unit for a day. If cooling comes back, you needed a service, not an overhaul.
- Shine a torch into the air outlet. Dark spots or a furry coating on the blower fan blades mean the build-up is deep.
- Notice smell and water. A musty smell or dripping water usually means the coil and drain pan are coated too.
- Think about the last wash. If a chemical wash did not help, the dirt is deeper than a wash on the wall can reach.
- Check for a blinking light. A blinking light means a fault code. Read our guide to Daikin blinking lights before you book a clean.
- Consider the gas. If the unit is clean and still warm, or a copper pipe frosts, low gas is more likely. That needs a gas check; see how we found a Daikin gas leak.
If step 4 applies, or the fan and coil are coated as in steps 2 and 3 and a wash has not fixed it, a chemical overhaul is the right job. Otherwise start with a chemical wash.
What happens in a chemical overhaul
Step | What we do |
|---|---|
Check | Note how the unit cools and look for other faults |
Pump down and remove | Gas is pumped back into the outdoor unit; the indoor unit comes off the wall |
Strip | Casing, blower fan and drain pan come off, leaving the coil |
Chemical and PowerJet | Coil chemical breaks down grime and mould; the PowerJet flushes it out of the fins and fan blades |
Refit | Unit dried, reassembled and reconnected at the flare joints |
Evacuate and test | Joints tested for leaks, air and moisture pumped out of the pipes, gas released, gas checked and topped up if needed, cooling and drainage tested |
It takes at least 45 minutes to an hour or more per unit. For a side-by-side comparison with a wash, read chemical wash vs chemical overhaul.
Why the coil gets this bad
In Singapore, aircons often run every night for years. The coil is cold and wet while it runs, so any dust that slips past the filter sticks to it, and mould grows in the damp. Layer by layer, the fins close up. Cooling fades so slowly that many people only call when the room never gets cold at all, as this customer did.
What it costs
Job | Price | What drives it |
|---|---|---|
Chemical overhaul, 1 wall unit | S$180 | Per wall unit; ceiling cassettes quoted after inspection |
Chemical wash (if the dirt is not deep) | S$120 per unit | Unit stays on the wall |
Every chemical overhaul includes a free gas check and top-up (worth S$165) and a deep evacuation (worth S$395). Washing the outdoor unit, when it needs it, costs extra. Servicing carries a 90-day warranty.
When to call a technician
Book a check if your Daikin cools much more slowly than it used to, never gets the room cold, smells musty or drips water. Book online in under a minute, or ask Luna, our AI assistant, on WhatsApp at any hour.
Frequently asked questions
Is a chemical overhaul safe for my Daikin?
Yes, when it is done properly. The electronics are removed or protected, the chemical is rinsed out with the PowerJet, and the pipes are tested and cleared of air and moisture before the gas goes back in.
Will it happen again?
Not for a long time if the unit is serviced regularly after the overhaul. Regular servicing cleans the coil and blower fan before the build-up gets deep.
Will my Daikin need gas after the overhaul?
Every chemical overhaul includes a free gas check and top-up. If the gas is far too low, that points to a leak, which we will tell you about and repair separately.
Is the overhaul covered by warranty?
Yes. Servicing, including a chemical overhaul, carries a 90-day warranty, and flare joints we remake during the overhaul are covered.
Can a chemical wash fix the same problem?
Sometimes. If the dirt is on the surface, a chemical wash on the wall is enough. When the coil is coated deep inside, as in this job, only an overhaul gets it all out.
Eric Lim, aka Uncle EricFounder of iAircon.Repair, now in its 10th year servicing aircons in Singapore. Some of our jobs are filmed, and you can watch the work on YouTube.
