Aircon capillary tube

A capillary tube is a thin pipe that controls how much refrigerant flows in some aircon systems.

Think of it like a straw that limits water flow. It keeps the cooling side supplied with the right amount of refrigerant.

Not all systems use capillary tubes. Some use a different control valve instead.

Capillary tubes get clogged with dirt or frost over time. A blockage restricts how much refrigerant flows.

You notice cooling becomes weak or unstable. The temperature may swing up and down. Sometimes ice forms on pipes.

These symptoms look like refrigerant leaks or airflow problems. This is why proper testing is needed first.

Technicians first check the most common causes: refrigerant leaks and airflow blockages.

If those check out fine, they test the refrigerant flow and pressure in the metering section.

They compare how the system behaves when running versus when stopped. This tells them if the tube is blocked.

Replace the tube if testing shows it is blocked and causing cooling problems. Do this before the system overheats.

You can wait if cooling is weak but still works and the tube blockage is minor.

Do not wait if temperature swings are happening more often. Blockage gets tighter over time.

Capillary tube repair is a refrigerant system job. It is more complex than basic cleaning.

Finding the real problem saves time and money. Testing first prevents wrong parts being replaced.

Most cooling problems come from leaks or airflow, not from capillary tubes.