What It Does
The capillary tube is a narrow, precision-length copper tube that acts as the metering device in many household refrigerators. It controls the flow rate of refrigerant from the high-pressure side (condenser) to the low-pressure side (evaporator), regulating the expansion of refrigerant into the evaporator coil.
Why It Fails
The most common cause of capillary tube failure is a blockage — caused by moisture freezing inside the tube, oil contamination, or debris circulating through the system. A partially blocked cap tube results in poor cooling; a fully blocked tube means no cooling at all.
Signs It Needs Replacing
- Fridge not cooling despite the compressor running
- Evaporator coil icing up heavily and unevenly
- Hissing or gurgling sounds from inside the unit
Estimated Part Cost
- Capillary tube (generic/universal): $5 – $30
- OEM capillary tube assembly: $20 – $80
Estimated Labour Cost
- The part is inexpensive, but the labour is significant. Replacing a capillary tube requires opening the sealed system, which involves:
- Refrigerant recovery
- Unsoldering and resoldering copper lines
- Installing a new filter/drier
- Vacuuming and recharging the system
- Total cost (parts + labour): $300 – $700
Important Note
Capillary tube replacement is almost always bundled with filter/drier replacement, as opening the sealed system exposes it to moisture. Never replace one without the other.