Aircond Making Gurgling Sound at Night — Refrigerant Line Air Trapped in Setapak Flat

The Customer's Situation

Cik Nurul Huda, a young executive living alone in a studio flat in Setapak, contacted us about a strange gurgling sound coming from her bedroom aircond. The Midea 1.0HP wall-mounted unit had been making the sound for about two weeks, and it was especially loud at night when everything else was quiet.

"It sounds like someone is pouring water inside the aircond," Nurul described over WhatsApp. "It starts about 10 minutes after I turn on the aircond and then comes and goes throughout the night. Sometimes it stops for an hour, then starts again. I can't sleep properly."

What made this case interesting was the timing. Nurul mentioned that the gurgling started about a week after she'd had a freelance technician come to top up the gas. The aircond wasn't cooling well, so she found someone on Facebook offering cheap gas top-up service for RM60.

Diagnosis: Improper Gas Top-Up Procedure

Our technician Rizal arrived and immediately suspected the issue based on Nurul's description. The timing — gurgling starting after a gas top-up — was a classic sign of trapped air in the refrigerant system.

Here's what likely happened: when the previous technician topped up the gas, he didn't properly vacuum the service hose before connecting it to the system. This introduced air into the refrigerant line. Air doesn't compress and flow the same way as refrigerant does, so it creates bubbles and turbulence as it circulates — resulting in the gurgling sound.

Rizal connected his gauges to the outdoor unit's service port and confirmed two things:

1. Gas pressure was slightly erratic — fluctuating more than normal, which indicates air contamination in the system.
2. Outlet temperature was 15°C — higher than the 12-13°C you'd expect from a healthy 1.0HP unit, confirming that the trapped air was reducing cooling efficiency.

The Fix: Proper Vacuum and Recharge

The only proper fix for air contamination in the refrigerant system is to recover all the gas, perform a full vacuum to remove all air and moisture, and then recharge with the correct amount of fresh refrigerant.

Why the Vacuum Step Is Critical

Many budget technicians skip the vacuum pump step during gas top-up to save time. They just connect the gas canister directly and pump in more refrigerant. This might work okay in some cases, but if there's already air in the system — or if air enters during the connection — you end up with exactly the problem Nurul experienced.

A proper vacuum pump procedure takes about 30 minutes and requires specific equipment, which is why cheap operators often skip it. But it's an essential step to ensure the refrigerant system is clean and performs optimally.

The Result

After the proper vacuum and recharge, Rizal ran the aircond for 20 minutes with all panels closed. Complete silence — no gurgling, no bubbling, no water sounds. The outlet air temperature was a solid 12°C, and the gas pressure readings were stable and within spec.

Nurul was relieved. "I thought something was seriously wrong with the aircond," she said. "Turns out it was the guy who did the gas top-up didn't do it properly."

As Rizal explained to her, this is unfortunately a common issue when customers go with unqualified or suspiciously cheap technicians. A proper gas top-up should include a leak check, vacuum (if needed), and pressure testing — not just pumping gas in and leaving. You can learn more about common causes of aircond gurgling sounds in our detailed guide.

Pricing Breakdown

• Diagnosis and inspection: Included
• Gas recovery and system vacuum: RM80
• R32 gas recharge (full charge for 1.0HP): RM80
• Filter cleaning and drain pan flush: RM20
• Total: RM180

Yes, this was more than the RM60 Nurul originally paid for the budget gas top-up. But now her system is properly charged with no air contamination, cooling at peak efficiency, and — most importantly — completely silent at night.

Lesson: Don't Cheap Out on Gas Top-Up

This case is a perfect example of "pay cheap, pay twice." The original RM60 gas top-up didn't include proper procedure, created a new problem, and Nurul ended up paying RM180 to fix it — a total of RM240 for what should have been a RM120-150 job done right the first time.

When choosing an aircond repair service, always ask:

• Will you perform a vacuum before recharging?
• Will you check for leaks?
• What type of gas will you use? (Make sure it matches your unit's specification)
• Do you provide a warranty on the work?

Customer Feedback

"Finally I can sleep in peace! The gurgling sound was driving me crazy for two weeks. Rizal explained everything clearly — why it happened and what he was doing to fix it. Now my aircond is colder than before and completely quiet. Should have called Total Aircond first instead of that Facebook guy!"

— Cik Nurul Huda, Setapak