Is it actually a problem?
Many current refrigerators use inverter or variable-speed compressors. They are designed to run at low speed for long periods rather than cycling on and off, so a refrigerator that is always quietly running may be completely normal.
It is a problem when:
- The refrigerator runs constantly and temperatures are above 40°F (fresh food) or 0°F (freezer)
- The compressor area is unusually hot to the touch
- Your electric bill rose noticeably
- The noise changed or got louder
Common causes
- Dirty condenser coil — the top cause in Las Vegas
- Failed condenser fan — the compressor overheats without it
- Hot location — a refrigerator next to an oven, in direct sun, or in a garage
- Door gasket leaks — warm air enters continuously
- Defrost failure — an iced evaporator cannot move air, so the refrigerator never reaches its set point
- Refrigerant leak — reduced capacity means the compressor can never catch up
What you can check
- Clean the condenser coils.
- Make sure there are a few inches of clearance around the refrigerator and that the front grille is not blocked.
- Test the door gaskets with a dollar bill.
- Check the back panel of the freezer for heavy frost.
What a refrigerator technician checks
- Compressor run time against room temperature, and whether it is a variable-speed design
- Condenser condition and condenser fan operation
- Door gasket seal and door closing
- Evaporator frost pattern for defrost or refrigerant problems
- Compressor current draw and temperature
- Sealed-system performance if the rest checks out
Frequently asked questions
How many hours a day should a refrigerator run?
A conventional single-speed refrigerator often runs 30 to 50 percent of the time, more in a hot kitchen. Variable-speed models can run close to 100 percent of the time at low speed and still be healthy.
Does running constantly damage the compressor?
A healthy variable-speed compressor is designed for it. A single-speed compressor that never stops because it cannot reach temperature is under stress, and the underlying cause should be fixed.
