The short answer
Grinding, knocking, rattling and rumbling are four different faults on the F line, and which one you have decides whether this is a five-minute job or a drum-out repair. This page separates them by when the noise happens rather than by how it sounds.
What you observe
- Knocking or banging only during spin, with the cabinet moving — That is balance and suspension rather than rotation: the tub is hitting its travel limits instead of being damped.
- A rumble that rises with spin speed and falls away as the drum slows — Speed-linked noise is the bearing signature, and it is the one noise that gets steadily worse week on week.
- NEAR MISS - noise on a brand-new installation — Transit bolts left in place are the classic version of this, and they produce dramatic noise with nothing wrong at all.
- Scraping that starts the moment the drum turns and never stops — Something is in contact continuously, which places the fault between the drum and the tub rather than in a bearing.
- NEAR MISS - a loud drain pump that sounds like grinding — Drain pumps are noisy by nature, and grit in one sounds far worse than it is. Check the filter before assuming a mechanism has failed.
Likeliest causes first
- Worn suspension dampers or springs — The knocking-on-spin cause. The tub travels further than it should and meets its limits, and the noise arrives with visible cabinet movement.
- Drum bearing worn — Last, and earned rather than assumed: the bearing signature is a rumble that tracks spin speed and that has grown over weeks, not a noise that appeared overnight.
- Door seal chafing on the drum — A squeal or rub that follows drum rotation at any speed, and one of the few noises that is visible with the door open.
- Machine out of level or a foot not carrying weight — Second, because it is invisible and free to fix. On these cabinets the counterweight sits high, so a small tilt becomes a large movement at speed.
What to check first, second, third
- Open the drain filter and look for debris — Third because it needs a towel and a tray, but it finds the coins and the grit that produce the worst-sounding faults.
- Check whether the transit bolts are out — Do this first on any machine that has moved recently: it is a two-minute look at the back panel and it explains dramatic noise instantly.
- Turn the drum by hand with the power off — A continuous scrape or a gritty feel that you can produce by hand is a much stronger finding than any noise heard across a room.
- Note exactly when in the cycle the noise happens — Fill, wash, drain and spin use different components, so the timing narrows the suspect list before anything is opened.
Power down first
Safety
Power down at the plug first, then turn the water off at both taps. Everything behind the front panel is within reach of a live supply, and a hose that comes free under pressure empties a room in a minute.
Models in the F family
Reference| Model number | Family key |
|---|---|
| F12 | bosch:washer:f |
| F23 | bosch:washer:f |
| F44 | bosch:washer:f |
| F44-CA10 | bosch:washer:f |
| F44-CA10-Ahi | bosch:washer:f |
| F55C-AVG1.5CU | bosch:washer:f |
| F55C-PG1.5CU-i | bosch:washer:f |
Where the owner fix ends
Call when the machine has to come out from under a worktop. Built-under and stacked installations need the height and the plumbing reset afterwards, and doing that badly produces a new fault on the first spin.
Other pages for this family
Lead Appliance Repair Technician · 12 years experience
Experienced technician with 12 years specializing in washing machine and dryer repairs across all major brands.
