Go to the website https://www.recalls.gov/cpsc.html
You can find all open and some older recalls on this site.
This applies only to USA - if you are not in the US, you will need to consult your local government to find recalls.
Most recalls are also listed on the manufacturer's website.
If your machine is sill under warranty your'e lucky, the humidity sensor will be replaced by them, otherwise google for the correct part, and get it from e-bay etc, DIY. Good Luck
www.soleushomecomfort.com/.../tpl.../HMT-D70EIP-A%20Manual%2012-01-15.pdf