Why does an AC lose gas?
An AC is a sealed system, so it does not use up gas the way a car uses fuel. If the gas is low, it has leaked out. Common leak points are the flare joints where the copper pipes meet the indoor and outdoor units, the service valves, and corroded or damaged coils. Refilling without repairing the leak only brings the problem back.
Signs your AC may be low on gas
- AC runs but cooling is weak
- Ice or frost on the thin copper pipe outside
- Outdoor unit runs for very long periods
- Hissing or bubbling sound near a joint
- Oily marks at pipe joints
- Low-gas error code on some inverter models
Dirty filters, a failed fan or a faulty sensor can cause the same symptoms, so we measure the pressure before deciding.
How we do it
- Check the pressure with gauges to confirm the gas is low.
- Find the leak using a pressure test and leak detection on joints, valves and coils.
- Repair the leak by re-making the flare joint, brazing the pipe or coil, or replacing the faulty part.
- Vacuum the system to remove air and moisture before charging.
- Charge the correct gas to the amount your model needs.
- Test the cooling and the pressures with the AC running, in front of you.
Which gas does your AC use?
The gas type is printed on the label of the outdoor unit. Most newer home ACs use R32 or R410A; many older ones use R22. These gases cannot be mixed or swapped, so we charge only the gas your AC is designed for. Send us a photo of the outdoor unit label when you book and we will bring the right cylinder.
When a leak cannot be repaired cheaply
Sometimes the leak is inside a corroded coil. Then the choices are repairing the coil, replacing it, or deciding whether the AC is worth the cost. We tell you the options and the cost before any work starts. Visit and inspection charges depend on the appliance and your location. We tell you the charge when you book.
Common questions
Does an AC need gas refilling every year?
No. An AC is a sealed system. If it needs gas, there is a leak somewhere, and the leak should be repaired before refilling or the gas will escape again.
How do I know my AC is low on gas?
Signs include weak cooling, ice on the copper pipe at the outdoor unit, and the outdoor unit running for long periods. These signs can also have other causes, so we measure the pressure before charging.
Which gas does my AC use?
Most newer ACs use R32 or R410A; older ones use R22. The gas type is printed on the outdoor unit label. We charge only the gas your model is designed for.
Last updated 26 October 2026