Fridge freezer compressor running constantly and never switching off (all brands)

A fridge freezer that never seems to stop running — no regular quiet periods between compressor cycles — is worth investigating, since some near-continuous running is normal in hot weather or when freshly stocked, but genuinely constant running usually means the appliance is struggling to reach its target temperature.

What to check first

1. Check the thermostat/temperature setting hasn’t been knocked to its coldest setting, which makes the compressor work harder and longer to reach an unnecessarily low target.
2. Check the door seals on both compartments for gaps or debris preventing a full seal (see our door-seal guides) — constant warm air ingress is one of the most common causes of a compressor that can’t catch up.
3. Check the vents inside the fridge compartment aren’t blocked by food packets, and that there’s clear space behind and above the appliance for ventilation.
4. Check you haven’t recently added a large quantity of warm food at once, which temporarily forces the compressor to work harder until everything cools — this should settle within a few hours, not be a persistent state.

When to call an engineer

If seals, vents, and thermostat setting are all fine, loading is normal, and the compressor still runs with no real breaks over a day or more, a refrigerant leak or a failing compressor may be the cause — worth a professional check, as this is regulated refrigerant work, not a DIY job.