PDF manuals, guides, data sheets are a valuable resource which is poorly archived and tends to disappear easily because companies die or simply don't care about their out of commerce products.
The main (accessible) resource in Internet Archive is https://archive.org/details/manuals but a series of manual websites have been preserved within web crawls.
Other archival projects
The web is infested with various domains which crawl manuals and compete for the best positioning in search results for very possible product code. Most of them try to monetize the clicks by obfuscating the PDF or other scam-like techniques.
- wikipedia:Category:Home appliance manufacturers
- According to a report, the 50 most important home appliance manufacturers are: Amica Wronki (Poland); Arçelik (Turkey); Aucma (China); Bertazzoni (Italy); B/S/H/ (Germany); Candy Hoover (Italy); Chunlan (China); CNA Group (Spain); DACOR (United States); Dongbu Daewoo Electronics (South Korea); Daikin (Japan); De' Longhi (Italy); Electrolux (Sweden); Elica (Italy); Franke Artemis Group (Switzerland); Galanz (China); GE Industrial (United States); Godrej Appliances (India); Gorenje (Slovenia); Gree (China); Haier (China); Hisense Kelon (China); Hitachi (Japan); LG Electronics (South Korea); Liebherr (Switzerland); Mabe (Mexico); Meiling (China); Midea Group (China); Middleby Corporation (United States); Miele (Germany); Mitsubishi Electric (Japan); Nortek (United States); Panasonic (Japan); Rinnai Corporation (Japan); Robam Appliances (China); Saiyi (China); Samsung Electronics (South Korea); Sharp Corporation (Japan); Smeg (Italy); Supor (China); Teka (Spain); Toshiba (Japan); Vatti Corporation (China); Vestel White Goods (Turkey); Videocon Industries (India); Weili (China); Welbilt (United States); Whirlpool (United States); Xinfei Electric (China)