Aircon not cooling in Pattaya? Find the cause before topping up gas
“Air comes out but it isn’t cold” has several possible causes, and adding refrigerant without finding the leak usually brings the problem back within months. MCS diagnoses the actual cause first, then quotes before any work starts.
The common causes, most frequent first
Low refrigerant from a leak
The refrigerant circuit is sealed. If the level has dropped, there is a leak. Topping up alone buys time; the leak needs finding at the pipework, flares or coil.
Dirty indoor or outdoor coil
Dust and film stop the system rejecting heat. The unit works harder and cools less. Many cases are solved by cleaning it properly.
Outdoor fan not turning properly
If the outdoor unit cannot shed heat, pressure rises until the system cuts out. Typically it cools at first, then gradually stops cooling.
Compressor not running
Could be the capacitor, a relay, the electrical supply, or the compressor itself. It needs measuring rather than guessing from symptoms.
Unit too small for the room
If it cools but never cycles off, the issue may be capacity rather than a fault. Check your room size before assuming a breakdown.
Remote set to the wrong mode
Fan or Dry mode gives airflow without cooling. Worth checking before booking a technician — it costs nothing to rule out.
What you can check yourself first
- Set the remote to Cool, 24–25°C, with the fan on its highest speed.
- Take out the filters. If they are clogged with dust, wash them and try again.
- Look at the outdoor unit: is the fan turning, and is warm air coming out?
- Listen for the compressor — running, or completely silent?
- Still not cooling? Photograph the model label and send a short video on LINE for an initial assessment.
If the unit is dripping water, smells of burning, or keeps tripping the breaker, switch it off and call a technician. Do not keep using it.
What happens when you call MCS
1. Send the symptoms first
Photos of the unit, the model label and the symptoms on LINE. We give an initial read and likely direction before travelling out.
2. Diagnose the real cause
Electrical values, refrigerant pressure and heat rejection are measured, so the cause is identified rather than guessed.
3. Quote before repairing
Inspection and repair starts at ฿1,500. If parts are needed, the part and labour price is confirmed with you first.
If it turns out cleaning will fix it, we will say so and offer the cleaning level that suits the unit instead of an unnecessary repair.
Frequently asked
Should I just top up the refrigerant?
No. The circuit is sealed, so a low level means a leak. Topping up without finding it usually means the cooling fails again within months, and paying for gas twice.
What does an inspection cost?
Inspection and repair starts at ฿1,500 per visit. If parts are required, we confirm the parts and labour cost with you before proceeding.
Is it normal to cool more slowly over time?
Some efficiency loss from dirt build-up is normal. A clear drop within a few months of a clean suggests something else is going on and is worth checking.
Will cleaning make it cold again?
If dirty coils and filters are the cause, cleaning helps noticeably. If the cause is a refrigerant leak or the compressor, cleaning will not fix it — which is why we diagnose first.
Which areas do you cover?
Pattaya, Jomtien, Bang Lamung, across Chon Buri and Rayong. See the service areas page.
Send the symptoms first, decide after
Photograph the unit, the model label and what it is doing, and send it on LINE. We will give you an initial assessment before booking anything.