Error Code Q1 is the air purifier produces an unusual noise after it's turned on.
+ Make sure the plastic bag is removed from the HEPA & Activated Carbon Filter and properly installed.
+ Make sure the air purifier is working on a hard, flat, and even surface.
+ The air purifier may be damaged, or there may have foreign objects inside. Please stop using the air purifier and contact Welov customer service. Do not attempt to repair the air purifier yourself.
Other Error codes https://manualsfile.com/article/welov-air-purifier-error-code-troubleshooting-69.html