to add to my question, not sure if it's relevant but I also plan on having a water softener (I do plan on getting a water test first) if that has any bearing on the above.

thanks!

If you want pharmaceuticals and "everything else" filtered, your best choice is an RO (reverse osmosis). This can be installed under your sink (or in a utility room if that is more convenient) with a dedicated drinking water faucet and plumbed to your refrigerator and an instant hot. Just make certain your instant hot has a stainless steel tank and your drinking water faucet is low lead. RO will also remove sodium, making softened water taste better.

Water treatment should start with a complete test by a certified lab and include: TDS, pH, hardness, iron, lead, sulfates, nitrates, alkalinity, manganese, bacteria, VOCs.

In general, your system order should be:

Well & tank OR city water --- Iron/manganese/sulfate removal (if necessary) --- Softener (if necessary) --- distributed throughout house.

Drinking water should be a branch off of your treated water and may include additional filtration for health/taste reasons. My personal preference is RO because it gets pretty much everything. Drinking water can then branch out to sink, refrigerator, instant hot, etc.

Thank you very much! So I understand you both correctly - does that mean I would have 3 separate faucets on the kitchen sink? i.e. the main kitchen sink faucet, instant hot, and drinking. (I would rather avoid one of those bulky filter-things that attach to the main sink faucet...)

Of course if the fridge we buy ends up having a water dispenser that would simplify things I suppose. Right now it will be between the integrated side-by-side Jenn Air, and I'm looking at Liebherrs this week.

Am I understanding that right? Thanks again for the replies, very good advice that I will look into.

You don't need 3 separate faucets. I have two: the main faucet I use for washing (which isn't filtered) and then a small hot/cold faucet that's hooked to the filter and the instant hot. I left the filtered cold dispenser out of my original description because it's integrated with the instant hot system.

The filter faucet I have is this one, I think. The only thing I don't like about it is that the hot lever is spring-loaded as a "safety" feature, so you have to hold it down to keep the water flowing. (I put "safety" in sneer quotes because I think it's less safe to force me to keep my hand near the hot water.)

I actually have a ice/water dispenser on the fridge too. It dispenses chilled water, but it comes out quite a bit more slowly than the non-chilled water from the hold/cold dispenser by the sink. I tend to use the one on the fridge for a quick glass of ice water and the one by the sink for filling pitchers and other big stuff.

I didn't try hooking the main faucet up to a filter because I think it would take a big filter to maintain the water pressure and flow rate you'd want from a faucet used for washing dishes, rinsing vegetables, etc.

If I have time I'll try to post some photos of what my set-up looks like from above and below the sink. I may have to do a bit of cleaning first, though. :-)

Depending on how carried away you want to get, a whole-house filter is an option. My next-door neighbor the plumber re-piped his house and put a big whole-house filter and softer system in his garage. It's two sealed units about 1 foot in diameter and 4 feet high each. He says they have to be changed every 5-10 years depending on how bad the city water is. I can ask him for the brand and model number if you'd like. It looked like a big job to install, though, not a DIY project. (Even for me, and I'm not afraid of sweating copper pipes.) And I'm sure we're talking at least a couple thousand dollars for the equipment and labor.

Laura

The issue with instant hot and RO water is the tank material and the faucet material, which is why I specified the tank MUST BE stainless steel and the faucet must be low lead. It hasn't anything to do with the rate your RO produces water.

Get in touch with a local water treatment company. Have them come out and test your water (you still want to get a test from a certified lab - they are more accurate and test for more contaminants) and see what they recommend. Water treatment is my area of expertise - I would be happy to evaluate their recommendations if you would like.

I put in an instant hot/RO system and have relayed my experiences. Here are a couple of threads that I participated in regarding your question.

http://ths.gardenweb.com/forums/load/appl/msg0817454812740.html

http://ths.gardenweb.com/forums/load/appl/msg07011114974.html?10

jscout's system in that first thread is almost exactly what I was trying to describe, but s/he did a much better job of it. The only difference is that I have a cheapo filter instead of RO. I have the same sort of faucet and vented tank.

The whole thing was fairly easy to install, aside from the fact that I totally stink at compression fittings. I think I tend to over-tighten them even when I'm thinking "don't over-tighten this". I'd rather just use solid copper with sweated joints, but all the parts are set up for compression fittings.

Laura

thanks all very much, i will look into these scenarios and check it out. thanks!

We have a whole house water softener (potassium softened water) and we have a undersink RO water filtration system attatched to that is an under sink instant hot water system! We need to replace the under sink instant HOT water heater (200 degrees C tempature. )

Who makes these and which is the best brand and what is the cost?

Can I get a direct email responce?

There are two RO downstream water heaters, In-Sink-Erator, and Waste king/Anaheim/Everpure/Ready Hot.

The difference is the ISE 2/3gal water 160-210F 3 yr warranty https://images-na.ssl-images-amazon.com/images/I/D1tdNcF5EWS.pdf. https://images-na.ssl-images-amazon.com/images/I/71PhqtuXjdS.pdf

The Waste King group has 2.5 qt tank, 190F 1-3 yr warranty (per model) https://images-na.ssl-images-amazon.com/images/I/91+ovJgoQpL.pdf https://images-na.ssl-images-amazon.com/images/I/51RMP44ZzFS.pdf

Hello. I have an Aquasana undersink water filter that feeds a separate faucet next to my main sink. I'd like to add a tankless undersink instant hot water heater that is also fed by the filtered water coming out of the Aquasana. Can I tee off the tubing coming out of the Aquasana and have one branch go to the instant hot water heater and the other go to the cold water nozzle? Wasn't sure if there would be pressure or tubing diameter/materials issues. The Aquasana outputs through flexible plastic tubing which I suspect would need to be adapted for the hot water input. Thanks in advance!