Quick AC Check vs In-Depth Diagnosis: Why a Fixed Unit Can Fail Again

When a Calibee technician comes to repair your air conditioner, the default is a quick check: about 20 minutes to find the most likely cause of the symptom you reported and fix it on the spot. Most jobs end there. Some don’t. The real cause sits deeper, inside the ceiling, the wall or the circuit board, and only shows up after the visible problem has been fixed. Here is why that happens, how the warranty works, and how to avoid paying twice.

What a quick check covers

In about 20 minutes the technician will:

• Run the unit and read any error codes.
• Measure gas pressure and current draw.
• Check the filters, indoor coil and fan.
• Check the visible parts of the drain line and copper pipes.

You then get a quote, and work starts only when you approve it. The visit charge is 150,000 VND per visit and is not deducted from the repair.

A quick check works well for problems on the outside: clogged filters, a blocked drain outlet, low gas, a failed capacitor. Its limit is just as clear: it only sees what can be seen and measured from the outside.

What needs in-depth diagnosis

These are quoted separately and only done with your approval.

Three real cases

1. Ceiling drain pipe: cleared, then leaking again weeks later

A ceiling cassette was leaking water. On the quick check the technician found a blocked drain, cleared it, and the leak stopped. At the next cleaning the unit leaked again. This time the gypsum ceiling was opened: the concealed drain pipe had been installed almost flat, with no proper fall. Water sat in the pipe, algae built up fast, and the pipe kept blocking every few weeks.

Clearing the pipe was not wrong; it fixed the blockage. The root cause was the pipe gradient, and the only lasting fix was to re-route that section. That was an existing installation fault, outside the work done, so it was not covered by the earlier repair’s warranty.

2. Completely out of gas: recharged, then found major damage

The unit wasn’t cooling and had no gas left at all. Without gas it can’t be test-run, so it had to be recharged first. Once running, the technician found the outdoor unit and the circuit board had also failed. Repairing both would cost close to a new unit, so the owner replaced it. The gas recharge was money spent on a unit that couldn’t be saved.

There is no way to know whether the board or compressor still works before the unit has gas to run on. For older units, the technician will explain this risk before recharging so you can decide.

3. Unit cutting out now and then

The unit switched itself off from time to time, but ran normally when the technician arrived. The quick check found dirty filters; after cleaning, it ran fine. A few days later, on a hot afternoon, it cut out again. The real fault was a sensor on the board that only misread when hot. Catching that kind of fault means measuring while it happens, which is in-depth diagnosis.

How the warranty works

In short: if the symptom returns because of the part we fixed, it’s covered. If it returns because of a different cause a quick check couldn’t see, it’s a new job.

We know this can be frustrating: the same symptom, another bill. But if every visit meant opening ceilings, nitrogen tests and board diagnostics, every repair would take hours and cost far more, including the many that only need a new capacitor or a cleared drain. The quick check keeps most repairs affordable; the trade-off is a narrower warranty.

Which to choose

• First fault, newer unit: a quick check makes sense.
• The same fault for the second time or more: go straight to in-depth diagnosis; it costs less than repeated fixes.
• Ceiling cassette, ducted or concealed piping: tell the technician if the unit has leaked water or lost gas before.
• Older unit, completely out of gas: ask about the risk before recharging.

Book a check in the Calibee app, or see prices and packages on our Aircon Services page.