In short
A noisy KTN dryer is telling you which part is wearing, provided you listen before you look. Start with rollers that have developed a flat and now thump, and note whether the noise follows the drum's rotation or runs continuously — that distinction splits the list in half.
What this looks like
- A squeal that rises as the machine warms up — Classic belt or idler-pulley noise; it often fades as things expand and then returns cold.
- A scraping sound with the drum turning — Something rubbing where it should not: a worn drum glide or an item caught between drum and bulkhead.
- A deep rumble that gets worse over months — Support rollers wearing, which is a gradual and entirely normal end-of-life for that part.
- NEAR MISS — a burning smell with the noise — Stop the machine and leave it off. A burning smell with a noise is not a diagnosis to make over several loads.
The causes in order of likelihood
- Rollers that have developed a flat and now thump — The drum turns on small support rollers, and those rollers are a designed wear item. As they wear they go out of round, and the drum then thumps once per revolution — the most recognisable dryer noise there is. It leads because this dryer reaches it before it reaches anything else, and because the check needs no tools. This is a value-tier unit built to a price, which usually means fewer sensors and simpler controls: the mechanical causes rank above the electronic ones here.
- Drive belt worn, or the idler pulley squealing — The drum is turned by a long thin belt held in tension by an idler pulley. The belt frays with age and slaps as it passes; the idler bearing dries out and squeals, usually louder cold and quieter once warm. Second, and the last of the causes that a careful look will settle on its own.
- Cabinet touching a wall or the washer next to it — Laundry rooms make this worse than most spaces: machines sit close together on hard floors, and a washer spinning next to a dryer will transmit its own vibration straight through. Third in order, and the point where the checks start costing more time than they save.
- Lint and debris packed into the blower housing — It ranks where it does because the noise is distinctive and because clearing the obstruction often also fixes a drying-time complaint at the same time. Last: it accounts for the smallest share of these calls, and every check above it is quicker to make.
Where to look, and in what order
- Turn the drum by hand with the power off and feel for a catch or a thump — A roller with a flat spot can be felt through the drum as a regular resistance. First: the answer here changes everything you do next.
- Listen for a regular slap rather than a continuous squeal — A slap that repeats quickly is a frayed belt passing its pulley. Next, because it takes the same few minutes and covers the other likely half.
- Push each top corner in turn and see whether the machine rocks — Any movement means a foot is not taking its share, and the cabinet is free to drum. Only worth doing once the two above are ruled out.
What an owner can safely check
- Note how the noise has changed over the last few months — Gradual worsening is wear; a sudden arrival is an object or a belt.
About 10 min
- Run a short cold cycle and note exactly when the noise appears and fades — That timing is what tells a technician which of the two parts to bring.
About 20 min
- Ease the machine forward so nothing touches the wall or the machine beside it — Leave enough room that the duct is not crushed when it goes back.
About 20 min
- STOP as soon as the fault is narrowed to a part rather than a condition — Naming the part is the useful outcome of an owner check. Fitting it is the other half, and it is not the same job.
The safety part
Safety
Switch off at the breaker before working on the machine, and treat lint as what it is — fuel. A restricted duct and a hot cabinet are how dryer fires start, so clear the air path before you run it again. If it is a gas machine and you smell gas: do not switch anything on or off, leave the building, and call the gas utility or the emergency number from outside.
The line between a fix and a call
Call when the noise survives an empty drum, a level check and a clear duct — at that point it is rollers, a belt or a blower wheel, and all three mean a panel off. None of them is expensive, and all get worse if left.
Nearby pages
What this page leaves out
This page covers KTN dryers as a class, not one family or one model line. Where a family- or model-specific page exists for your unit, that page is the more specific answer and the one to read first. Deliberately not here: wiring colours, torque figures and part numbers, all of which differ by family.
Lead Appliance Repair Technician · 12 years experience
Experienced technician with 12 years specializing in washing machine and dryer repairs across all major brands.
