Why is Your Aircon Not Cold?
Is your aircon running but blowing lukewarm air when the afternoon heat hits? That’s the moment most Marine Terrace, Marine Crescent and Marine Drive households start searching for aircon not cold repair.
The good news is that the cause is usually one of a few things.
- A dirty coil or filter that chokes airflow
- Low refrigerant from a slow leak
- A failed part, such as a capacitor or thermistor
- A rusted condenser on a sea-facing unit
We see these every week in Marine Parade flats. Most are quick to pin down once someone checks the unit properly.
Dirty filters and coils
A blocked filter is the most common culprit. According to a Singapore aircon troubleshooting guide from Mega Furniture, it cuts airflow across the evaporator coil, so cooling drops even when the compressor and gas are fine.
NEA advises checking your air filter monthly and having the unit inspected annually. If you have 2 to 4 wall-mounted units, rinse all the filters on the same day. You’ll quickly spot which room’s unit is clogging fastest.
If the filter is clean and the air is still warm, the coil itself is probably caked with dust and grime. That needs a proper chemical wash, not just a filter rinse.
Low refrigerant
Refrigerant isn’t used up like petrol. If the level is low, there’s a leak somewhere, and topping up without finding it only buys you a few weeks.
Our technician measures gas pressure first, then tells you whether a gas top-up is enough or a deeper repair is needed. Aircons.sg puts 2026 gas top-ups in Singapore at S$60 to S$180 per unit, depending on whether the unit uses R32, R410A or older R22.
Failed parts such as capacitors and thermistors
A weak capacitor can stop the outdoor fan or compressor from starting properly. The indoor unit still blows air, so it feels like the cooling has simply given up. A faulty thermistor (the small sensor that reads room temperature) can also make the unit shut off early.
Helpling’s Singapore guide says capacitors can last 10 to 20 years, but power surges and humidity can shorten that. It puts replacement at S$140 to S$240 including labour.
| Common fix | Typical Singapore market cost |
|---|---|
| Gas top-up (R32 to R22 units) | S$60 to S$180 per unit |
| Capacitor replacement | S$140 to S$240 including parts and labour |
Use these ranges as a sanity check for any quote you receive, ours included.
Rusted condensers on sea-facing units
Living near the coast changes the game. A Marine Parade case write-up from Snowflake Aircon explains that salt plus moisture corrodes the aluminium fins against the copper tube. The outdoor coil stays wet with rain and dew, so it suffers more than the indoor one.
Once fins corrode, a wash can’t bring them back. Corroded fins let air pass without touching metal, so the unit loses cooling even when everything else works.
BCA also tells owners to check outdoor unit brackets and ledges for corrosion at least every 6 months. Take a look at yours the next time you hang laundry.
What happens when we visit
Our technician works through the same checks every time, so nothing gets guessed.
- Check airflow, filters and the indoor fan.
- Inspect the coil condition.
- Measure gas pressure.
- Examine the outdoor unit, including the condenser and capacitor.
You get the cause explained in plain language, then a fixed quote before any repair starts. Repairs start from S$60, with same-day slots subject to availability.
Not sure which fault you have? For other issues, see our full aircon repair service. If your unit runs but won’t cool, book an aircon not cold repair visit today and we’ll find out why.
