The short answer
A new noise on the KM line is usually a mounting or contact problem rather than a failing part: a cabinet this light is moved by its own compressor, so how it stands decides what you hear. Most of what follows can be tested in minutes without a tool.
What the owner actually sees
- A hard knock at the start of each run — One thump as the compressor picks up, then a steady hum; often another at the stop.
- A rattle that comes and goes within a run — It appears for a few seconds at a particular point and then clears on its own.
- A continuous whine while air is moving — It tracks the fan rather than the compressor and stops when the fan does.
- NEAR MISS - loud and the cabinet is warming — Noise with a cooling complaint is a cooling fault first. The not-cooling page for this line covers it, and it is the combination that needs a technician.
What it usually turns out to be, in order
- The cabinet not standing squarely — Ranked first on this line: a compact cabinet weighs little relative to the thump its compressor makes, so a corner that is not carrying weight lets the whole case rock at every start and stop. What the owner hears is a knock, and what is actually happening is the cabinet moving against the surface it stands on.
- Contents and baskets vibrating — It deserves a place in the ranking rather than a footnote: it is the single commonest explanation for a new noise in a unit that has not changed otherwise.
- Loose fasteners, a cover or a grille — Then: the noise is usually intermittent, because the panel only buzzes at one point in the cycle when the frequency matches, and that intermittency is the clue.
- Compressor mounts that have perished — Last, and the reason the order matters: the compressor sits on rubber mounts, and when those harden the unit transmits everything it does into the case. The noise is a hard knock at start and stop rather than a hum.
Working order, and the reason for it
- Press each corner in turn — Press down on each corner of the top. Any corner that moves is the one making the noise, and packing it out is the whole repair.
- Run the unit empty for a minute — Refill in stages and listen after each. The item that brings the noise back is the one to separate from the wall or the rail.
- Rest a hand on each panel while it runs — Press a flat hand against each panel and the rear cover in turn. A noise that stops under your hand is a panel, and tightening or padding it is the repair.
Before you open anything
Safety
Unplug the appliance or switch off its breaker before removing any panel; a capacitor can hold a charge after the power is off. A fan can start without warning while the unit is live, so never reach into a machinery bay to feel for a noise on a running unit.
Models in the KM family
Reference| Model number | Family key |
|---|---|
| KM15 | alpicool:refrigerator:km |
| KM20 | alpicool:refrigerator:km |
Where owner work ends
Call once stance, load, panels, clearance and the surface have all been excluded and the noise is still there, because what remains is inside the machinery bay. Call immediately for a burning smell, a trip, or a noise that arrived together with a warming cabinet.
Nearest pages of this class
Lead Appliance Repair Technician · 12 years experience
Experienced technician with 12 years specializing in washing machine and dryer repairs across all major brands.
