Evidence grade: B1 — Trade practice
Refrigerator failures run power → settings → seals → airflow → coils → fans, in that order; most turn out to be something you can check in ten minutes with no tools. The sealed refrigeration system (compressor, refrigerant lines) is always a professional's job — this tree stops before it.
Effort: Easy · 10–30 minutes · no tools required for most checks; vacuum with brush attachment for coils
PPE and ventilation
Unplug the fridge before touching the condenser coils. Normal room ventilation is sufficient. Never chip frost off with a knife or sharp tool — refrigerant lines run close to the surface and puncturing one vents refrigerant [1].
Diagnostic tree
1. Is the light on — does the fridge have power? - No → Check the plug, the breaker, and test the outlet with another small device. If the outlet works and the fridge stays dead → call a pro (control or wiring fault). - Yes → go to 2.
2. Is the thermostat set correctly (about 3–4 °C / 37–39 °F fridge, −18 °C / 0 °F freezer), and has it had a full day after any change? - No → Set it correctly, give it 24 hours, then re-judge. - Yes → go to 3.
3. Is the door closing and sealing fully (paper-strip test: shut the door on paper — if it slides out with almost no resistance, the gasket is worn or dirty)? - No → Clear anything blocking the door, clean the gasket, and check the fridge is level enough for the door to swing shut. - Yes → go to 4.
4. Are the interior vents (back/top of the fridge section, fed from the freezer) blocked by food? - Yes → Pull items away from the vents and the back wall; cold air can't circulate through a wall of leftovers. - No → go to 5.
5. (Unplug the fridge.) Are the condenser coils (behind the bottom grille or on the back) caked with dust and pet hair? - Yes → Vacuum with a soft brush attachment, without bending the coils or pulling wiring. Dusty coils make the fridge run longer and cool less. - No → go to 6.
6. Listen while it runs: do you hear the evaporator fan (near the back of the freezer) and condenser fan (bottom rear)? - No fan sound, or rattling/squealing → a failed fan is likely — call a pro. - Fans run → go to 7.
7. Is there thick frost on the freezer's back wall or ice around the vents? - Yes → The defrost system (heater, sensor, control) is failing. Call a pro — do not chip the frost off with tools. - No → go to 8.
8. The fridge runs constantly but stays warm; you hear clicking/buzzing with repeated start-stop; you see oily residue on refrigeration lines; or the breaker trips when the compressor starts. - Yes to any → Stop and call a pro. These point at the sealed system or a failing compressor. Do not open or add anything to the sealed system, and do not bypass any safety device [1]. - No → Overloading or heavy use may be the cause: let a packed fridge catch up for a few hours with the doors closed, then reassess.
Food safety while you sort it out
Refrigerated food stays safe about 4 hours without power if you keep the door closed (a full freezer holds longer). Past that, or if you're unsure — discard perishables: meat, dairy, cooked leftovers, cut fruit. When in doubt, throw it out [1].
Stop rules
- Sealed system (compressor, evaporator, refrigerant lines) → professional only. No exceptions.
- Burning smell, scorched plastic, or smoke → unplug if safe, and call emergency services if there's smoke or fire [1].
- Clicking/buzzing + warm interior = failing start relay or compressor — pro.
Honest limits
- "Freezer cold, fridge warm" is a classic pattern: it usually means cold air isn't reaching the fridge section — blocked vents, a dead evaporator fan, or a defrost problem [1].
- Coil cleaning helps only when the coils were actually dirty; if they're clean and the fridge still won't cool, the tree's later nodes are the answer.
- Standalone freezers in garages run differently in temperature swings — this tree covers kitchen refrigerators [1].
Sources
- Direct Fix Appliance Repair (Ottawa) — "Fridge Not Cooling? 8 Quick Checks Before You Call a Repair Tech" — https://ottawaappliancepro.ca/blog/fridge-not-cooling-8-quick-checks-before-you-call-a-repair-tech/
Repair Lab · Release 1 · Evidence last checked September 30, 2026 · A project of AOJEL