We've had two houses out here and both have separate reverse osmosis systems in the kitchen for the sink, dishwasher and refrigerator water. We also have a water filtration system under the sink along with it. I'm assuming that the plumber was correct, otherwise you'd be drinking some salty water!
Beach,Shea built my home, so I can empathize with you about plumbing issues. When my home was built, Shea used a company called Riggs plumbing (I believe they are now Epic). The plumbers included one of my outside hose bibs in the softener loop, excluding the cold water to a bathroom in the process. Maybe GB's plumber friend worked on my home... As I tried to explain to GB, there is a standard for the softener loop, and that standard excludes the kitchen cold water. Virtually every (and maybe even every) RO unit installed uses non-softened water as its input. An RO unit setting under a kitchen sink gets its input water from the kitchens cold water supply line because that is non-softened water.
Flyer,We are talking about a softener loop excluding the kitchen faucet's cold water supply, that is all.Can we agree RO units use non-softened water?Can we agree installing an RO unit in a home built in Trilogy or Vistancia, does not require the installer to run a separate water line for an RO unit in the kitchen?For years it has been standard practice to exclude the kitchen faucet cold water from the softener.
Without a softener installed, how does one determine the cold water is in the loop?
Staying with the kitchen included yes or no question (it is both yes and no), let me ask you a something. Presuming you will agree there's a lot of RO units setting under a lot of kitchen sinks all of which are providing non-softened drinking water. You readily admit an RO unit is there to provide non-softened drinking water. I agree with you on this. Why do you think the RO units are setting under the kitchen's sink, and why do you think the RO unit gets its water from the kitchen's cold water supply line? Are there two cold water supply lines under the kitchen sink... ummmm that would be, no. The RO unit is under the sink so it can get its non-softened input water from the kitchen's cold water supply. Kinda makes sense doesn't it.
The kitchen sink is both included and excluded from the softener loop, because the hot water is definitely in the softener loop.
I need to hear Skips thoughts on this topic before I can take a side. For all we know, this could be the HOA's fault.
GB,Next you'll be telling me its common for homes to have a second hot water heater so the kitchen hot water can be out of the loop, or maybe you know of another way to get hard water from the heater at only the kitchen sink.
3M,The hot water at the kitchen sink is softened, unless you have a second water heater that supply's hot water to the kitchen sink.