Why Is My Fridge Humming? A Guide to Normal and Abnormal Sounds
Fridges are never completely silent — they produce various sounds during normal operation. But there's a difference between the normal hum of a healthy appliance and the sounds that signal a problem. This guide breaks down the most common fridge noises and what they mean.
Normal Fridge Sounds
Steady Low Hum
A steady, low-pitched hum is the sound of the compressor running. This is completely normal. The compressor is the motor that drives the refrigeration cycle. It runs for a period, cools the fridge to the set temperature, then switches off. If you hear a hum that starts, runs for 10–30 minutes and then stops, this is exactly how a healthy fridge works.
Clicking Sound When Starting or Stopping
A single click or small clunk when the compressor starts or stops is normal. This is the sound of the relay switch engaging or disengaging, and the expansion and contraction of internal components as temperatures change.
Gurgling or Bubbling
Gurgling sounds are caused by refrigerant flowing through the pipes and evaporator coils. This is completely normal and common in most fridges. If you notice it more after adding warm food to the fridge, that's also normal — the system is working harder to restore temperature.
Cracking or Popping
Intermittent cracking or popping sounds, especially after a defrost cycle, are caused by plastic interior panels expanding and contracting with temperature changes. This is normal and doesn't indicate a fault.
Sounds That May Indicate a Problem
Loud or Rattling Hum
If the normal compressor hum becomes noticeably louder or takes on a rattling quality, this can indicate:
- The fridge isn't level — check the feet and adjust so the fridge is stable. A vibrating case will amplify compressor noise significantly
- Something is resting against the back of the fridge or the fridge is too close to a wall, causing vibration
- The compressor mounting bolts have come loose (requires a technician)
- The compressor itself is wearing out (more likely in fridges over 10 years old)
Constant Running Hum (Never Switches Off)
If the compressor seems to run continuously without cycling off, this may indicate:
- A faulty door seal allowing warm air to constantly enter (the fridge can't reach temperature, so the compressor never rests)
- The thermostat is set too cold
- Refrigerant leak (the fridge can't cool efficiently so the compressor overcompensates)
- Blocked condenser coils at the back of the fridge (restricting heat dissipation)
High-Pitched or Squealing Hum
A high-pitched whine or squeal is less common and may indicate a fan motor issue. Modern fridges have fan motors that circulate air through the evaporator coils. If the fan blade is hitting ice build-up, or the motor bearings are wearing, a whining sound results.
Intermittent Buzzing or Humming From the Back
The condenser fan at the back of the fridge also runs periodically. If it starts buzzing rather than humming smoothly, the fan blade may need cleaning (dust build-up is common) or the fan motor may be failing.
Quick DIY Checks
- Check the fridge is level on all four feet — this eliminates vibration noise
- Pull the fridge slightly away from the wall — vibration against a wall amplifies sound
- Check that nothing is resting on top of or leaning against the fridge
- Open the fridge and check the door seal — test it with the paper test (described in our separate guide)
- Vacuum the condenser coils at the back or bottom of the fridge — dust build-up reduces efficiency and makes the compressor work harder
When to Call a Technician
If the fridge is running constantly, the inside temperature is higher than it should be, or the noise is new and getting louder, it's time to have a technician assess it. Early intervention is usually much cheaper than waiting for a full component failure.
If your fridge is more than 10 years old and developing multiple issues, Oceania Appliances can discuss cost-effective replacement options. We stock quality refurbished fridges across Sydney with free delivery.