Fridge running but not cooling? Here are the 7 most common causes, from a simple seal issue to a failing compressor, and what each one means for repair.
A fridge that’s running but not actually cooling is one of the most common calls we get — and one of the most misunderstood, because “not cooling” can mean seven different things depending on what’s actually failed.
1. A door seal that’s no longer sealing Cold air escapes constantly through a worn seal, forcing the compressor to run non-stop while the internal temperature still climbs. Test it with a piece of paper in the door — if it slides out easily, the seal has failed.
2. Dirty or blocked condenser coils Coils caked in dust can’t release heat properly, which reduces cooling efficiency and strains the compressor. This is one of the easiest issues to prevent with occasional cleaning.
3. A blocked evaporator fan or vent Overpacking a fridge, or storing something against an internal vent, restricts airflow to parts of the unit — often showing up as one shelf staying warm while others cool normally.
4. Low refrigerant from a slow leak A gradual drop in cooling performance over weeks, rather than a sudden failure, often points to a refrigerant leak. This needs a technician — refrigerant handling isn’t a DIY fix.
5. A failing start relay or capacitor If the compressor hums but doesn’t kick in, or clicks on and off repeatedly, the start relay or capacitor is a likely culprit — a relatively inexpensive part, but one that needs correct diagnosis to avoid replacing the wrong component.
6. A faulty thermostat A thermostat stuck in the wrong position can leave the compressor running constantly without ever reaching target temperature, or shut it off too early.
7. Compressor failure The most serious and most costly cause — a compressor that’s worn out or has failed internally usually means the unit runs but produces little or no cooling at all, regardless of how long it’s left on.
What this means for you
Causes 1–3 are things you can often check yourself. Causes 4–7 need a technician with proper diagnostic tools — guessing at these risks replacing the wrong part and paying twice. See our full fridge repair guide for Kamakis and Ruiru for what to check first.
Fridge not cooling and not sure which of these it is? Book a diagnosis and we’ll tell you exactly what’s wrong before any work starts.
Suggested image: Technician inspecting fridge condenser coils — alt text: “Diagnosing why a fridge is not cooling in Kamakis”