Refilling the unit with water is essential just like when you try to lose weight and suppress your appetite, you need to drink enough water.
Be sure to use drinking bottled water, not distilled water in order to operate the unit.
Only refill one bottle of 500ml water once a month, and use the sterilization mode to remove any residues and bacterias inside.
Enjoy the warmest winter and good sleep with Navien Mate
Check out our bed heaters.