---
title: "Unusual noise"
description: "Sub-Zero unusual noise — buzzing, rattling, clicking or a compressor that sounds like it is working harder than it used to."
url: "https://subzeromiami.support/symptoms/making-noise/"
date_modified: "2026-08-18"
---


# Sub-Zero unusual noise

### The fastest diagnosis is the code

A fan code confirms in a second what a description of a noise can only suggest. If there is one on the display, read it before anything else.

### Noise is often the first symptom

Built-in refrigeration is quiet by design, so a change in sound is meaningful long before a temperature changes. A fan bearing on its way out, a condenser fan working against a blocked coil, or a compressor running longer cycles all announce themselves this way — weeks or months before anything appears on the display.

### What each sound tends to mean

- **A rattle that changes when the door opens** is usually the evaporator fan
- **A hum that has grown louder** often means the compressor is running longer, which points back at the condenser
- **Clicking every few minutes** can be a start relay struggling
- **Water sounds** are usually normal — defrost water finding the drain

### Worth a visit, or not?

A new noise with normal temperatures is not an emergency, but it is the cheapest moment to look. A new noise with a unit that is also drifting warm is a different conversation, and worth having this week.

New sounds, or louder ones

What it usually means

A hum that got louder over months

Rattling that stops when a door is opened

Clicking every few minutes

The fastest diagnosis is the code

A fan code confirms in a second what a description of a noise can only suggest. If there is one on the display, read it before anything else.

Noise is often the first symptom

Built-in refrigeration is quiet by design, so a change in sound is meaningful long before a temperature changes. A fan bearing on its way out, a condenser fan working against a blocked coil, or a compressor running longer cycles all announce themselves this way — weeks or months before anything appears on the display.

What each sound tends to mean

A rattle that changes when the door opens is usually the evaporator fan

A hum that has grown louder often means the compressor is running longer, which points back at the condenser

Clicking every few minutes can be a start relay struggling

Water sounds are usually normal — defrost water finding the drain

Worth a visit, or not?

A new noise with normal temperatures is not an emergency, but it is the cheapest moment to look. A new noise with a unit that is also drifting warm is a different conversation, and worth having this week.

The evaporator fan

A rattle that changes when the door opens is the signature, because opening the door changes what that fan is doing.

A condenser working against a blocked coil

A hum that has grown louder over months usually means the compressor is running longer cycles, and that points back at the condenser rather than at the compressor.

A start relay struggling

Clicking every few minutes, often with a unit that is otherwise holding temperature. It is cheap now and expensive later.

Nothing at all

Water sounds are usually defrost water finding the drain, and they are meant to happen. A new noise with normal temperatures is not an emergency — it is the cheapest moment to look.

Notice when the sound happens

A rattle that changes when the door opens is usually the evaporator fan. A hum that has grown over months points back at the condenser.

Record it on your phone

Ten seconds is enough, and a recording describes a noise far better than words do. It is the single most useful thing you can send us about this symptom.

Check the temperatures are still right

A new noise with normal temperatures is not an emergency — it is the cheapest moment to look. A new noise with a cabinet drifting warm is a different conversation.

Then book the visit

Tell us how long it has been making the sound. Weeks or months of it is useful information, not an embarrassment.

---

**[Read full article: Unusual noise](https://subzeromiami.support/symptoms/making-noise/)**