The compressor is the “heart” of any air conditioning system. When the compressor stops running, the entire cooling process fails — resulting in warm air, weak airflow, high electricity bills, and sometimes complete AC shutdown.
In Malaysia, this problem is more common than most homeowners realize, especially in older apartments, offices, shop lots, and high-humidity environments. Understanding the causes can help you avoid unnecessary repair bills and identify early warning signs.
What Exactly Does the Compressor Do?
The compressor pressurizes and circulates the refrigerant (gas) between the indoor and outdoor units.
If this component stops running:
No cooling will occur
Refrigerant cannot flow
Indoor coil will not get cold
Outdoor fan may run, but without effect
A non-running compressor is a serious issue that requires proper diagnosis.
1. Faulty Capacitor (Most Common in Malaysia)
The capacitor helps the compressor start.
When it weakens or fails, the compressor simply doesn’t turn on.
Typical symptoms:
– Outdoor unit fan runs but no cooling
– Sudden warm airflow
– Clicking sound
– Compressor tries to start but fails
Why Malaysia faces this often:
High humidity + long hours of AC usage = capacitor wears out faster.
Solution:
Capacitor replacement (affordable and fast).
2. Low Gas or Major Refrigerant Leak
If gas pressure is too low, the compressor will refuse to run to protect itself.
Operating without gas can damage the entire system.
Symptoms:
– No cooling
– Small or no vibration in outdoor unit
– Pipe ice formation
– Compressor shuts down within seconds
Solution:
Pressure test → Leak detection → Repair → Refill (R22 / R410A / R32).
3. Overheating Compressor (Thermal Cut-Off Activated)
The compressor has a safety system that shuts it off when it becomes too hot.
Heat occurs due to:
– Dirty outdoor unit
– Blocked airflow
– Fan motor failure
– Poor ventilation in the outdoor area
Signs:
– AC cools only for a few minutes
– Outdoor unit extremely hot
– Compressor resets after cooling
Solution:
Outdoor cleaning + proper ventilation check.
4. Faulty Outdoor Fan Motor
If the outdoor fan stops spinning, heat cannot escape.
The compressor detects the rising temperature and switches off.
Symptoms:
– Outdoor fan not rotating
– Hot air blowing from the outdoor unit
– Compressor starts but stops quickly
Solution:
Fan motor repair/replacement.
5. Electrical or MCB/RCCB Issues
Sometimes the compressor isn’t the problem — the electrical supply is.
Possible causes:
– Weak DB connection
– Loose wiring
– Tripping MCB
– Faulty relay
– Burnt terminals in DB box
Symptoms:
– AC switches off suddenly
– No power to outdoor unit
– MCB trips randomly
Solution:
Full electrical safety check.
6. Faulty PCB (Control Board)
The PCB controls the compressor, fan motor, sensors, and overall operation.
When PCB fails:
– Compressor never receives signal to start
– Unit may show blinking error lights
– Indoor unit works but no cooling
PCB issues are common in inverter units.
Solution:
Board repair or replacement depending on condition.
7. End-of-Life Compressor (Dead Compressor)
A compressor typically lasts 8–12 years depending on usage and brand.
A dead compressor shows:
– No vibration
– No humming sound
– No amp draw
– High current on startup but fails instantly
In such cases, the compressor must be replaced, or the entire outdoor unit upgraded.
How to Identify If It’s a Serious Problem
Stop using the aircond immediately if you notice:
Burning smell
Loud buzzing from outdoor unit
Frequent tripping
Compressor extremely hot
Outdoor unit shaking
No sound or activity from compressor at all
These signs indicate possible compressor failure or electrical danger.
What You Should NEVER Do
❌ Never keep restarting the AC if the compressor doesn’t run
❌ Never refill gas blindly without checking for leaks
❌ Never open the outdoor unit yourself
❌ Never bypass safety components (dangerous)
❌ Never run the AC with a frozen coil
A single mistake can cause full compressor damage — the most expensive AC repair.
Professional Diagnosis Is Essential
A proper technician will check:
✔ Gas pressure
✔ Capacitor health
✔ Ampere draw
✔ PCB signals
✔ Outdoor fan motor
✔ Compressor overload
✔ Wiring condition
✔ MCB/RCCB stability
Only after these tests can the real cause be identified.
Aircond Compressor Repair & Diagnosis – Subang Jaya & Klang Valley
If your aircond is not cooling or the compressor is not running, our team can provide:
✔ Full AC diagnosis
✔ Capacitor replacement
✔ Leak testing
✔ PCB repair
✔ Fan motor replacement
✔ Gas refill (R22 / R32 / R410A)
✔ Outdoor cleaning
✔ Compressor replacement
✔ Electrical safety inspection
Shop Information
Sumon Electrical & Hardware Trading
Lot K10004, Ground Floor, Goodyear Court 7,
USJ 14, Subang Jaya, Selangor
Google Map:
https://maps.app.goo.gl/CqTZ24KzNDvmfK1y8?g_st=awb
WhatsApp (24/7): +601116109510
Website: https://shababalsharif.com