1. Iced-over evaporator / failed defrost system (both compartments warm)
What it is: Frost builds on the evaporator coil behind the freezer back wall, chokes airflow, and within 24–48 hours the fridge drifts warm. Defrost heater, defrost thermistor, or control fuse failed. Symptom: visible frost on the freezer back wall when you pull the panel; fridge above 42°F; freezer above 10°F. Affects every brand.
Fix: Replace OEM defrost heater + bimetal + defrost thermistor (full kit — they fail together). Manual defrost first to restore cooling.
Typical all-in: $285–$425 all-in
2. Failed evaporator fan motor (fridge warm, freezer borderline)
What it is: The fan behind the freezer back wall pushes cold air across the evaporator and through the damper into the fridge. Bearings seize or windings short. Without airflow, the fridge warms first because cold air can't reach it; the freezer holds longer because it has the cold coil right there. Symptom: fridge warming faster than freezer; grinding or whining from the back of the freezer.
Fix: Replace OEM evaporator fan motor + blade. 45-minute repair through the freezer back panel.
Typical all-in: $265–$385 all-in
3. Stuck or failed air damper (fridge warm OR fridge too cold)
What it is: The damper between the freezer and fridge regulates how much cold air bleeds into the fridge. Stuck closed → fridge runs warm. Stuck open → fridge runs too cold and freezes produce. Common on Whirlpool, KitchenAid, Samsung French-door, and GE Profile platforms.
Fix: Replace OEM damper assembly (electronic auger-damper on Samsung/LG, mechanical on Whirlpool). 30–45 minute repair.
Typical all-in: $245–$365 all-in
4. Failed thermistor (temperature sensor — warm or cold drift)
What it is: Thermistors report compartment temperature to the control. Drifted out of spec, the control either keeps the compressor running (compartment goes cold) or shuts it down too soon (compartment warms). Symptom: temperature drift in only one compartment, no frost issues, fan and damper test fine.
Fix: Replace OEM fridge or freezer thermistor (often a full sensor harness). Verify resistance against OEM spec curve before closing the call.
Typical all-in: $195–$285 all-in
5. Packed condenser coils (both warm, compressor runs constantly)
What it is: Coils under the kick plate clog with dust, pet hair, and grease. Compressor can't reject heat, runs nonstop but can't pull down to setpoint. Symptom: both compartments warm by 5–10°F, compressor never cycles off, kick plate warm to the touch, cabinet sides warmer than usual.
Fix: Pull the kick plate, vacuum the condenser coil with a long-bristle brush, vacuum the fan housing. 30-minute service. We re-test temperatures after the clean.
Typical all-in: $165–$235 all-in
6. Door seals compromised (gradual drift, frost in freezer)
What it is: Hardened or torn door gasket lets warm humid air infiltrate. Frost builds in the freezer, defrost over-runs, both compartments warm gradually. Common on units 6+ years old. Symptom: gasket flat in corners, visible gap when door is closed, frost on the inside of the freezer walls.
Fix: Replace OEM door gasket. 30-minute repair, no cabinet pull required.
Typical all-in: $185–$285 all-in
7. Sealed system / compressor fault (last suspect)
What it is: Compressor weak, start-relay failed, or refrigerant leak. Symptom: click-and-rest at the back of the unit, no cooling at all, or cooling only at one compartment for hours after restart. LG linear-compressor units carry a 10-year sealed-system warranty — we file the claim. Most other brands the repair-vs-replace math favors a new fridge.
Fix: Sealed-system diagnostic with pressure gauges and electrical bench test. We give the honest answer on whether to repair or replace.
Typical all-in: Quote — often replace except on LG warranty platforms
