I've had mine for 3 years now.
Couple of mates almost as long.
Problems - Yes. need a tinker or 2 occasionally but no real gripes.
Mine clogged up with grit etc and required a flush out to get the flow going again.
I use a 17lpm pump and others are using 12 lpms.
Absolutely useless in the high country in winter!!!!!!
Water in the pipes freezes up and no flow = no go.............bummer.....
Still, what can you do with any HWS in this situation?
Would I buy another one - Hell yes.
Would I recommend them - absolutely
Are they legal - heck No, but at that price, I'm giving it a go.
Now sit back, relax, grab a glass of red and watch the nitpickers go all "electrical thread"on this
Cheers
Brian