I have one in the attic in my garage, we have had several freezes, down to 22 degrees F at times, still works ok, pipes are insulated,
No, this does not require a water softener in the system in order to last.
Yes, this can be used in addition to a whole house water heater.
yes, mine serves a bathtub/shower and a sink, you need to use the hot water valve for temperature control, turn on the cold water first at a low volume them mix in the hot water, it will keep up with the shower, there is a learning curve,
This unit is rated for .3 - 2 gpm but you also need to look at how cold the water is being fed to the heater is. The colder the water the lower the gpm of usable hot water produced. I use this only for a single sink which is all i would recommend for this unit.
A dedicated 30amp circuit is required using 10 Gauge 3 wire [ hot,nutueral, ground]. 12 gauge is to small for the amperage [for saftey].
You can order replacement elements from Eemax. They come with instructions and are relatively easy to replace. I have replaced them at my Church.
No. According to the manufacturer this unit is designed for a lavatory, for hand washing. It has a max flow of 2 gallons per minute. At full flow temperature rise will probably be less than 20 degrees. This unit draws 30 amps therefore minimum wire size is 10 gauge. This information can be found on the Eemax web page.