It sounds backwards in Singapore’s climate, but aircon units do freeze up here, and it’s more common than most people expect. Here’s what actually causes it and what to do about it.
1. Blocked Airflow
The most common cause. If airflow around the indoor or outdoor unit is restricted, whether from a dirty filter, an obstruction near the outdoor unit, or a unit that hasn’t been serviced in a while, the coil can drop below freezing and ice forms on it.
2. Sudden Drops in Outdoor Temperature
Less common, but it happens. On unusually cool days when the outdoor temperature drops significantly, the difference between the indoor and outdoor unit’s operating conditions can be enough to trigger icing.
3. Low Refrigerant
A refrigerant leak drops the pressure inside the system, and low pressure causes the coil to run too cold, freezing instead of just cooling. This is the cause that needs the most urgent attention, since it usually means a leak somewhere in the system. See our gas top-up guide for why the leak matters more than the refill.
What to Do If Your Aircon Has Frozen
Switch the unit off and let it thaw completely before running it again. Don’t keep turning it on and off trying to force it to cool, since that just repeats the freezing cycle without fixing the cause. Once thawed, book a repair to identify which of the three causes above is behind it.
Preventing It From Happening Again
Regular servicing catches the blocked-airflow cause before it gets bad enough to freeze the unit, and it’s the easiest of the three causes to prevent. If your unit has frozen more than once, that’s a sign of an underlying refrigerant leak that a one-time clean won’t fix.
FAQs
Is a frozen aircon dangerous?
Not immediately dangerous, but continuing to run it can strain the compressor. Switch it off and let it thaw rather than forcing it to keep running.
How long does it take for a frozen aircon to thaw?
Usually a few hours with the unit switched off. Don’t try to speed it up by scraping the ice, since that can damage the coil.
Will the freezing just go away on its own?
No. Whatever caused it, blocked airflow, temperature swings, or low refrigerant, will cause it to happen again unless it’s actually fixed.
How fast can you diagnose a frozen aircon?
Same-day slots are available across Singapore. WhatsApp us and we’ll advise before you book anything.
