Common fault
Why does frost keep building up in my freezer?
Short answer
Frost that comes back after you have cleared it means the defrost cycle is not finishing, and three things cause nearly all of it. The heater has failed, the thermistor that decides when to run it has drifted out of range, or a door gasket has lost its magnetic pull and is admitting humid air faster than the cycle can remove it. Out here there is a fourth: a long outage in fire weather leaves the cabinet warm and wet, and if the drain freezes on the way back down, the coil ices from that point on.
The reason to deal with this early rather than living with it is that ice is an insulator. A furred evaporator cannot transfer heat, so the unit runs longer, the compartment slowly gives up ground, and the display keeps reporting a number that stopped being true weeks ago. Nothing fails outright, which is precisely why it goes unfixed until the food says otherwise.
Garage and outbuilding freezers frost sooner on this side of the county, and the cause is ambient rather than a broken part. A unit spending an August afternoon in an unconditioned garage in Fallbrook or a shop building on a Valley Center property runs close to continuously, the defrost cycle never gets a quiet stretch, and humid air comes in every time the door opens on a hot day. If the appliance is fine and the room is the problem, we will tell you that.
On the visit the heater and the thermistor get measured rather than swapped on suspicion, the drain is cleared through to the pan while everything is open, and the gasket is checked for pull along its whole length instead of at the one corner everybody tests. Then the unit is run back up and re-checked at the basket before we go.
If that matches what your appliance is doing, say so when you call — it tells us which parts to bring, and most of these are finished in one visit.
Reviews
Our Sub-Zero freezer stopped working overnight. We called and had a technician at our Fallbrook home within hours. The repair was fast and professional—saved our entire freezer contents!" - Jennifer M., Fallbrook
- ★★★★★
Excellent service in Valley Center. The technician quickly diagnosed a sealed system issue in our built-in refrigerator and provided a clear, reasonable estimate. Highly recommended." - David L., Valley Center
- ★★★★★
Booked same-day service for our wine cooler in Bonsall. The repair technician was prompt and efficient, fixing the temperature and humidity controls perfectly. Very professional experience." - Sarah P., Bonsall
Appliance down in North County San Diego?
Tell us the brand and what it is doing — we can usually name the likely repair before we arrive.