2) Water tanks of air energy water heaters generally have sewage outlets, which need to be cleaned and discharged regularly (once every two years). You can call the brand's after-sales phone and let them arrange it;
3) If it is a stainless steel water tank, it is best not to use vinegar because there is an oxide layer on the inner surface of the stainless steel water tank. Although vinegar can remove scale, it may also corrode the stainless steel water tank, causing corrosion perforation and reducing the service life of stainless steel. Use with caution!