Common fault
Why does frost keep building up in my freezer?
Short answer
Frost that comes back after you clear it means the defrost cycle is not completing. Carlsbad Sub-Zero Specialists answers that on (858) 779-0698.
The reasoning behind that
Three things account for nearly all of it: a defrost heater that has failed, a thermistor reading out of range so the cycle never triggers, and a door gasket that has lost its magnetic pull.
How the diagnosis goes
What we check, in order: the actual compartment temperature at the shelf against 0°F; where the frost is forming, since frost on the rear wall and frost around the door frame mean different faults; the defrost heater's continuity; the thermistor's resistance against spec; and the gasket, tested warm and along the hinge side, where it takes its set first.
In Carlsbad the gasket version is more common than it would be inland, because the air coming in on a coastal morning carries far more moisture for the defrost system to shed. Clearing the frost by hand treats the symptom and removes the evidence, which is the main reason this fault gets diagnosed late. Once the evaporator is furred over it insulates itself, so cooling degrades gradually rather than stopping, and owners describe the unit as slowly getting worse rather than breaking. On the coastal side of the city that decline runs quicker, because every door opening on a humid morning adds moisture the cycle then has to shed.
If that matches what yours is doing, say so when you call — it decides which parts come on the van.
Appliance down in Carlsbad?
Tell us the brand and what it is doing — we can usually name the likely repair before we arrive.
Questions
Frequently asked questions
My wine column says it is at the set point but the bottles feel warm. Which do I believe?
The bottles. The sensor reads a spot the circulating air reaches, so the panel holds its set point while the racks sit several degrees above it. On a dual-zone column, a zone that drifts while the other holds is that zone’s evaporator, fan or damper rather than the sealed system. That is a two-minute call to Carlsbad Sub-Zero Specialists on (858) 779-0698.
Which parts of Carlsbad do you cover?
Carlsbad and La Costa are the core of the work: Olde Carlsbad, Aviara, Bressi Ranch and the estates across 92008, 92009, 92010 and 92011. Mention the street when you call, because salt air or several miles inland changes what we expect to find behind the grille. Call Carlsbad Sub-Zero Specialists on (858) 779-0698 and ask.