The short answer
A new noise from a Bosch WQB-series dryer is placed by rhythm before it is placed by part, and this platform changes the list of candidates: a ventless condensing dryer has running gear a vented dryer does not have. the heat-pump platform adds its own sounds on top, and some of them are normal. The ranking below is written for what is actually inside this cabinet rather than for dryers in general.
What you observe
- A rattle that comes and goes with the drum turning — Something loose that moves with the load rather than with the machine.
- A low rumble that rises with the drum speed — Running gear rather than contents, and it gets worse rather than better.
- A squeal or a chirp once per drum revolution — A rotating contact somewhere behind the drum.
- NEAR MISS - a hiss or a soft gurgle for a minute at a time — That is condensate and refrigerant doing what they are meant to do on a condensing machine. It is not a fault and it does not need chasing.
Likeliest causes here
- The load itself, or the machine not sitting level — A single heavy item and a floor that flexes together produce a walking, thumping machine that sounds broken. First on this family, and for a reason that belongs to the platform: this cabinet is light enough that the floor under it matters.
- Something loose in the drum or in the filter well — Coins, a zip pull, a wire from a bra and a button all make a noise out of all proportion to their size. Second here, and close enough behind the first to be checked in the same pass: it costs nothing to exclude and it explains most new noises.
- The blower wheel fouled or loose on its shaft — Lint packs one side of the wheel, it goes out of balance, and the note follows the airflow rather than the drum. Ranked third on these models: it is constant rather than rhythmic, which separates it from the drum.
- The drum support rollers flat-spotted or dry — A roller that has stood under load develops a flat, and every revolution finds it. Last, and the ranking is the point: a slow, steady worsening rather than a sudden change.
- Where this ranking departs from the brand-generic page — The cause that moves is the load itself, or the machine not sitting level. It leads on this family because the heat here comes from a refrigerant circuit rather than from an element. That is a property of the platform rather than of the brand, which is why the page above this one cannot rank it the same way.
Check in this order
- Run the machine empty and rock each corner — If the noise vanishes without a load, the load was the noise. A cabinet that rocks needs its feet set, not a part. It leads on these models because the construction puts it within reach before anything else on the list.
- Empty the drum, then look into the filter well with a light — Run a hand round the seal at the front of the drum as well. This is free and it ends most of these calls.
- Listen for whether the note tracks the air or the drum — An airflow note is constant through a cycle; a drum note comes once per turn.
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. Do not reach into a drum that is still coasting, and let the machine cool before opening the lower access flap. Never run this machine with the rear panel off to listen to it; the air path only works closed.
When to call
Emptying the drum, clearing the filter well, setting the feet and emptying the tank are all owner ground here, and between them they resolve most new noises. The line is the back of the drum: a grind that rises with speed, a belt that has to come off, or a circuit note that persists with the drum stopped all mean the cabinet comes apart.
Nearest pages
Lead Appliance Repair Technician · 12 years experience
Experienced technician with 12 years specializing in washing machine and dryer repairs across all major brands.
