It all depend s on the water quality, and in our area its very nasty
most people wont maintain them and the water softeners are sub standardor they dont put
salt in them so eventually everything gets crappy and
they will lime up ..... then the exchangers begin to flake off calcium and ruin single handle
faucets throughout the house and dishwashers.... ..I have seen a lot of this
I just dont need the headaches dealing with these issues
please ......make all the money you can with them.....