How Our Aircon Repair Works
Is your aircon blowing warm air, or not starting at all? Don’t guess at the cause.
Here’s how aircon repair works with us. The technician finds the cause first, then gives you a fixed quote before any repair starts. That way you pay for the fault that is really there, not for guesses.
It’s a sensible way to do it. City Cooling Engineering’s repair guide advises confirming the real fault before you pay, because a cheaper part like a capacitor can look like a failed compressor.
Repairs start from S$60 and cover faults such as:
- A failed capacitor
- A faulty sensor (thermistor)
- A PCB control board fault
- A failed fan motor
- Loose or burnt wiring
- A stuck contactor and drain problems
We work on all common brands, including Daikin, Mitsubishi Electric and Panasonic, both inverter and non-inverter. Got two to four wall-mounted units in your flat? Tell us which one is playing up and the technician will start there.
You pay after the job, once the unit is tested. All repairs carry our 90-day workmanship warranty.
Same-Day Emergency Repair in Serangoon
A breakdown on a hot night is not something you want to wait days for. We keep same-day slots for Serangoon, subject to availability, and urgent breakdowns get priority. Our hours are 7 days a week, until 9pm Monday to Saturday and until 8pm on Sunday.
While you wait:
- Switch the unit off at the remote and at the isolator switch.
- If the circuit breaker has tripped, do not keep resetting it.
- If water is dripping near electrics, keep the unit off and catch the drips.
- If you smell burning or hear grinding, keep it off. Do not run it “to see”.
Why the fuss about resetting? Snowflake Aircon’s guide on breaker trips explains that a breaker that keeps tripping is reacting to a real fault, such as a current leak, an overcurrent draw or heat damage at a wiring point. Aircons.sg adds that Singapore’s humidity and dust speed up insulation breakdown, so repeated resets can make a small fault worse.
Then WhatsApp us the symptoms, a photo or video, and your Serangoon address.
Which Repair Do You Need?
Many repairs start with a clear symptom. If you know what the unit is doing, these pages explain the likely causes in more detail:
| Symptom | Likely causes | Go to |
|---|---|---|
| Runs but room not cold | Dirty coil, low gas, failed part | Aircon Not Cold |
| Water dripping inside | Choked drain line, dirty drain pan | Water Leak Repair |
| Rattling, buzzing, grinding | Loose cover, fan motor, compressor | Noisy Aircon Repair |
| Slow loss of cooling over months | Refrigerant leak | Gas Top-Up |
| Blinking light, no start | Sensor, PCB, power fault | This page: aircon repair |
Water leaks are a good example of why symptoms matter. Billy Aircon says a choked drain line causes over 60% of the leak cases it attends in HDB estates, so a drain flush is often the first thing to check.
Common Faults We Repair
Unit does not start or trips the breaker
Often a failed capacitor, a stuck contactor or a wiring fault in the outdoor unit. The technician tests each one with a meter before quoting.
The timing of the trip is a useful clue:
- Trips the moment you restart: Snowflake Aircon says this usually points to a current leak or short.
- Trips only on startup: Aircons.sg says to suspect a locked compressor or a failed start capacitor.
- Humming but the fan will not spin: This is a classic capacitor symptom.
Tell us which one you see when you WhatsApp. It helps us bring the right parts.
Blinking error light
Inverter units show error codes for sensors, fan motors, drain pumps and communication faults. We read the code, then test the part it points to.
Reading the code depends on the brand:
- Daikin: The code appears on the remote, not on the indoor unit, according to VD Aircon Services. A U4 code means the indoor and outdoor units are not communicating, which Icare Aircon says often follows rainwater damage to the outdoor PCB.
- Mitsubishi Electric: Count the operation light flashes, pause, then count the timer light flashes. Billy Aircon gives two operation flashes followed by three timer flashes as Error 23.
Film the blinking pattern and send it over. A short video saves a lot of back and forth.
Outdoor unit not running
If the indoor fan blows but the compressor and outdoor fan stay silent, the room will not cool. Capacitors and control signals are the usual suspects.
Good news: the capacitor is usually the cheaper culprit. Aircons.sg’s 2026 price guide puts a capacitor part at around S$30 to S$60, while it lists compressor replacement as a much bigger job.
Unit switches off by itself
A faulty thermistor can make the unit think the room is already cold. Replacing the sensor fixes the cycle.
Billy Aircon suggests a quick check. If the temperature the unit reads differs from the real room temperature by more than two degrees, the thermistor is likely failing.
Repair or Replace?
Most faults are worth repairing. A capacitor or sensor is a small job. If the compressor has failed on a very old unit, the repair may cost more than it is worth, and we will tell you before you spend money.
Here are the rules of thumb that Singapore aircon firms commonly use:
- Age: Peak Cool says most residential aircon systems last around 8 to 12 years in Singapore’s climate.
- Cost: City Cooling Engineering suggests replacing if the unit is over 8 years old, non-inverter, or the quote exceeds 50% of a new unit’s cost.
- Compressor: SJR Air Conditioned says a compressor replacement typically runs S$400 to S$900, which is why age matters so much.
We do not do installation through this Serangoon service. For a new unit, contact our parent company Cool Earth Aircon, which Brian started in 2007 as a one-man workshop.
Not sure which side of the line your unit falls on? WhatsApp us the symptoms and a photo of the unit’s label, and we’ll give you an honest answer before you spend a cent.