Roblang3..what exactly are you asking? If you are sanitizing the lines or winterizing the unit?
Either way..remove your filter from housing and reinstall housing. You can run sanitizer through lines by valve on sanitize and turning pump on. Your filter can be stored as you see fit. Your on demand h/w heater does not have a drain..you have to winterize unit by allowing fluid to flow through the copper lines and core. Once your unit is winterized...it will also be winterized. Hope this helps.
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