It will still have all kinds of deadly bugs - pseudomonas, achromobacter, stenotrophomonas maltophilia (sp)... I could go on. Make sure you use a .2 micron filter. Any standing water in a storage situation or even if it just goes through the tankless heater, it is not hot enough long enough (10 minutes boiling plus 1 minute for each 1000 feet) to kill these pathogens.