Why is my aircon not turning on but has power?

If a light or display is on, power is reaching the unit and the problem sits between the remote and the board. Start with fresh batteries and check the mode is Cool. If the remote is fine and the unit still ignores it, the board or its receiver is usually the cause.

What does a blinking light on my aircon mean?

It is a fault code. The number of blinks, and which light is blinking, points to a specific fault, and the meaning differs by brand. Count the pattern and send it with the brand and model — we can often narrow the fault before we travel.

How much does it cost to repair an aircon that will not turn on?

The diagnosis is $50, free if we do the repair. The repair itself is quoted as one price for parts and labour before any work starts. Small electrical parts are at the cheap end, a control board at the expensive end. On an older unit we will say when replacing makes more sense.

Should I repair or replace an aircon that has died?

It comes down to the part and the age. A capacitor, contactor or fan motor is nearly always worth repairing. A board or compressor past ten or twelve years usually is not — you would spend a large share of a new unit on an old one. We give you both numbers and you decide.

Can I reset my aircon myself?

You can take the batteries out of the remote for a minute, and switch the unit off at the wall and back on after five minutes. That is as far as it safely goes. Do not open the isolator, the outdoor unit or the control box — there is mains voltage inside.

Aircon not turning on

Most aircons that look dead are not. Usually it is flat remote batteries, a wrong mode, a tripped breaker or a wall switch that got switched off. Check those four first. If it still will not start, or a light is blinking a pattern, that is a fault — a diagnostic visit is $50, free if we do the job.

Written by Wilson Lee, owner and lead technician at LM Brothers Aircond · 10 years in the trade · Reviewed 21 August 2026

A removed aircon fan motor with a rusted shaft beside its clean replacement

Why it happens

Three things have to line up before an aircon will run: power reaching it, a signal from the remote, and a control board healthy enough to act on that signal. Take any one away and you get the same result — nothing happens.

That is why a dead unit tells you so little. Flat batteries look exactly like a burnt-out board from where you are standing — one costs two dollars, the other is a real repair.

So we work through them in order. Power and the remote cost nothing to rule out, so they go first. Only once both are clear is a failed part inside the likely answer.

Not starting, or just not starting yet?

Switch a unit off and straight back on and many models will not restart for a few minutes. That is deliberate — the compressor is protected from restarting against pressure that has not settled. Give it five minutes before deciding it is broken.

The other harmless one: a unit that seems dead in fan mode but runs in cool. Some models behave differently between modes, and a reset remote can leave you in a mode you never chose. Set it back to Cool at 24 degrees.

What causes it, and what fixes each one

Flat remote batteries, or the wrong mode
The most common reason of all, and the cheapest. A remote with weak batteries may still light its screen but not have the strength to send the signal across the room. Others are simply in fan or timer mode, or set above room temperature.
The fix: New batteries, set the remote to Cool at 24 degrees, and point it at the unit from close up. If the display is blank or half-lit, that is your answer.
A tripped breaker, or a switch someone turned off
No power reaching the unit, and nothing on it to show for it. A breaker can trip in a storm, or when something else on the circuit faults. A wall switch, or the switch beside the outdoor unit, gets turned off during painting and never turned back on.
The fix: Look at the aircon breaker in your DB box, and any wall switch feeding the unit. A tripped breaker can be reset once, with dry hands. If it trips straight back, leave it off and call — resetting it is not safe. Aircon repair in Singapore
A light on the unit blinking a pattern
Most brands report faults by blinking. The number of flashes, or which light is on, points to something specific — a sensor, a fan motor, a communication fault between indoor and outdoor. The same pattern means different things on a Daikin, a Mitsubishi and a Midea.
The fix: Count the blinks, note which light is doing it, and send that with the brand and model over WhatsApp. It often narrows the fault before we travel, so we arrive with the right part. Aircon repair in Singapore
A failed capacitor or contactor at the outdoor unit
The indoor unit lights up and responds, but nothing cools and the outdoor unit sits silent or hums without starting. Two ordinary wear parts sit behind this, and both fail more often as a unit ages.
The fix: A diagnostic visit. These are cheap parts and a satisfying repair — a unit written off as dead often runs again the same visit. Not a DIY job at any level: there is stored charge inside an outdoor unit even after the power is off. Aircon repair in Singapore
A dead control board
The board receives the remote signal and decides what runs. Power surges, lightning, damp and age all kill them. Signs are a unit with confirmed power that does nothing, no beep from the remote, or a light that blinks and never clears.
The fix: Boards can sometimes be replaced and sometimes not, depending on whether the part is still made. We price it as one number and tell you how it compares with a new unit — past ten or twelve years, a board is often where replacing beats repairing. Aircon repair in Singapore

Technician checking the control box of an aircon indoor unit with the cover removed

What you can check yourself

Put fresh batteries in the remote: A fresh pair, not the ones from the TV remote. Check the screen lights up properly, then point it at the unit from a metre away. This fixes more dead aircons than anything else.
Check the mode and the temperature: The remote should read Cool — not Fan, not Dry, not Timer — and the temperature should be below the room temperature. Set 24 and give it five minutes.
Look at the breaker in your DB box: Find the switch labelled for the aircon and see whether it has flipped. With dry hands you can reset it once. If it trips straight back, leave it off and call us.
Check the wall switch, and any switch by the outdoor unit: Both get switched off and forgotten, usually after painting or a spring clean. Turning a switch back on is fine. Opening anything is not.
What not to touch: Do not open the isolator box, the outdoor unit casing or the indoor control box, and do not touch wiring or terminals. There is mains voltage inside, and stored charge that stays live after the power is off. Past the four checks above it is a technician's job — and the visit costs nothing if it turns into work we do.

When to call someone

The breaker trips again as soon as you reset it
Any burning smell, hot plastic smell or buzzing from the unit or switch
Any scorch mark, melted plastic or discoloured socket
A light blinking a pattern that will not clear
Confirmed power and fresh batteries, and it still does nothing
The indoor unit responds but the outdoor unit hums and will not start

What it costs

If you do not know what is wrong and want us to find out, the call-out is $50, or $120 for VRV and VRF systems. It is free if you go ahead with the repair — you only pay it if you leave the unit as it is.

The repair is quoted as one number covering parts and labour, and you hear it before we start. Nothing appears on the bill that you did not agree to. No GST, and every job carries a 90-day workmanship warranty.

Some units are not worth repairing, and we would rather say so than take the money. A capacitor on a seven-year-old unit is an easy yes. A board or compressor on a fifteen-year-old one usually is not, and we will price a replacement instead, including taking the old set away.

We work 8am to midnight every day including public holidays, island-wide, with no travel charge. Same-day is possible most days, though we will not promise a slot before checking.

See the full price list