Not Cooling · sign 3 of 6
Frost or Sweat on a Refrigerant Line
Frost or beads of water on a refrigerant line you can see means cold is reaching further along the circuit than it should, and only gauges settle why.
Sub-Zero Repair Sammamish · (425) 610-8986 · $89 service call, credited
- Compiled by
- Marta Fennimore
- Holds
- EPA 608 certified
- Dated
- Years at the work
- 12
What you notice
A copper line behind the grille wears frost or drips water
With a flashlight through the grille, or with the back of the unit in view during other work, you spot a length of copper tubing furred with frost or shiny with sweat. Sometimes the first sign is a small puddle or a damp patch under the unit, with no ice maker leak to explain it.
The cabinet may still feel cold, or it may have drifted a few degrees warm. Either is worth writing down before anyone looks at it.
Sub-Zero Repair Sammamish · (425) 610-8986
What it points to
Cold is turning up past the coil where it belongs
The evaporator is meant to be the cold end of the circuit. When frost or condensation forms on the tubing leading away from it, refrigerant is leaving the coil colder than it should, and the reasons fall into two broad families.
The first is too little heat reaching the evaporator: a fan that has stopped, a coil choked with ice, or a door that no longer seals and keeps feeding the cabinet moist air.
The second lies inside the sealed system, such as a charge that is off or a partial restriction. Neither can be seen from outside. Pressure readings taken with gauges tell them apart, and that is technician work.
Sub-Zero Repair Sammamish · (425) 610-8986
Safe checks
Checks that leave the line itself untouched
Look and listen only. Never touch, wrap, heat or scrape a refrigerant line, not even to clear the frost.
- Look for ice inside the freezer
Heavy ice on the rear wall or around the fan cover is worth describing when you call; it points toward the airflow family.
- Watch each door close
Every door should shut fully on its own gasket, with no tears, flattened stretches or packaging holding it open.
- Take the cabinet temperature
A thermometer in a glass of water on a middle shelf gives a steadier reading than the display; note it with the time.
- Look again tomorrow
Check the same stretch of line the following morning and evening, and note whether the frost stays, spreads or clears.
That is where an owner's part ends. Panels, wiring and refrigerant are a technician's work — Sub-Zero Repair Sammamish, (425) 610-8986.
When to call
Call when the frost keeps coming back or the cabinet warms
Frost that stays on the line from one day to the next, or any warming inside the cabinet, is the point where watching stops paying off. Fans, defrost parts and the refrigerant charge are all tested behind panels, and the charge needs gauges on the system.
Tell Sub-Zero Repair Sammamish where on the line you saw the frost and what the thermometer read. The $89 service call is credited to the repair.
Sub-Zero Repair Sammamish · (425) 610-8986
