Common fault
Why does frost keep building up in my freezer?
Short answer
Frost that comes back after you clear it means the automatic defrost is not finishing its cycle. Carmel Valley Sub-Zero Care reads that at the coil rather than off the display: (858) 290-7997.
Why we start there
Three causes cover nearly all of it: a failed defrost heater, a thermistor out of range, or a door gasket whose magnet admits damp marine-layer air all morning.
What happens next
The ice itself is what does the damage. A coil furred with frost is insulated by it, so heat transfer drops, the compartment runs a little warmer every week, and the display goes on reporting the number it was asked to hold. Owners describe this as the freezer gradually getting worse rather than breaking, which is exactly what it is. By the time drawers are frozen into their runners, the coil has been struggling for months and the contents have been cycling through temperatures they should never have seen.
What we check, in order. Where the frost is: light and even across the back wall is humidity, a heavy pad in one area is defrost. Then the heater, for continuity. Then the thermistor, against its resistance curve at a known temperature. Then the drain, because a drain that iced closed usually iced for the same underlying reason. Then the seal, with a sheet of paper closed in the door at several points around the frame, top edge first. Integrated units get their door alignment checked at the same time, since a dropped door and a tired gasket look identical from the outside.
If that matches what yours is doing, say so when you call — it decides which parts come on the van.
Appliance down in Carmel Valley?
Tell us the brand and what it is doing — we can usually name the likely repair before we arrive.
Questions
Answers before you call
How is the price agreed, and what actually happens on the visit?
In two steps, both before any work. What the visit costs is quoted when you call (858) 290-7997. Then the grille and covers come off, readings are taken at the components, and the repair gets one number covering parts and labor. Approve it and that is what Carmel Valley Sub-Zero Care charges.
Is it better to repair or replace my Sub-Zero unit?
Almost always repair. What fails on these is an ordinary component — a fan motor, a defrost heater, a gasket, an ice maker module — and the condenser comes out through the grille. Replacing a built-in means matching a cabinet opening and a panel front, which is joinery, not appliance work. Carmel Valley Sub-Zero Care will say which it is on (858) 290-7997.