[rsynnott]

The likes of Comsumer Report have tended to find that modern front-loading machines are almost universally more effective than the old low-efficiency top loaders popular in the US, and can also attain much higher temperatures (fairly basic models can do a >90 degree C wash, say). So that’s probably not it.

Though there might be an element of misuse. My machine warns in the manual to do a 60or 90 degree wash with no clothes every couple of months to clean the machine. I suspect most people don’t do this.

[weavie]

Would it be necessary to do this wash without clothes? I missed that bit and generally do a high temperature wash with my sheets figuring I am killing two birds with one stone...

[bartman]

Should be fine with clothes. My Siemens has a cleaning reminder that turn on after a month or so unless at least one wash with 60C or higher has been done.

[rsynnott]

The manual normally says "with no clothes", but I'm not sure what the basis for that is.

[sandworm101]

Bleach also works. Run a hot load, with or without actual laundry, and enough bleach to kill everything.

[greedo]

Doing a 90C wash may kill some germs, but it'll do a better job of killing your clothing. Delicate mode is the best thing for your clothes.