I've got a roughly 15 year old Whirlpool under-sink RO unit that has developed a constant internal leak that must be going straight down the drain. My smart water meter reported a minor leak a while back and I've finally tracked it down to the RO unit. I don't think I'm going to try to repair this one, just the filters alone will be $100 or so and it looks like fairly decent RO units are in the $200-400 range. Probably just time for a new one.

Anybody have recommendations for a good quality RO unit? This is for drinking water and fridge mounted ice-maker duty only. Family of 5.

I don't know current offerings but whatever you get make sure it doesn't use proprietary filters. Get something with generic filter housings and a standalone RO membrane.

Oh yeah good call

When I was into salt water aquariums, these guys were the go to local place and highly recommended.

https://www.buckeyehydro.com/

Thanks, I'll give them a look

you do realize this is normal for reverse osmosis systems, right? for every gallon of purified water, you are sending 3 or more straight down the drain. ditch the RO if the losses are bothersome

if its NEVER turning off, its likely faulty ASO

https://a.co/d/9v9H5oW

I have been very happy with my Ispring unit I bought 3 years ago.   My summertime TDS values can 600 and this unit can get it down to 20 TDS.    The winter values are even better because our water is better and I can have single digit TDS readings.   The only time I had a problem, switching out all the O-rings solved some higher TDS readings.  

Give them a look.

KW3

Yeah I'm aware that the RO unit uses water to make clean water but should only do that when it's actively refiling, not running 24hrs per day all week. I'm totally fine with the normal waste to clean usage. This one never stops. 30-40 gals per day running through it daily and we're taking maybe 2 gallons. Smart water meter data shows a continuous base flow which I can stop when I shut the valve off to the RO unit.

However, your comment got me to looking into the waste a bit deeper and it looks like my current membrane is just a couple months shy of 3 years old. I found a table that describes how much water a membrane uses as it ages and the use spikes up dramatically by the time the membrane reaches 3 years old (with average usage I assume). Starting out at a waste:clean ratio of 2:1 or 3:1 and then up to a waste ratio of 30 or 40:1 by the time it's 3 years old. This might explain my situation, I know to expect the waste ratio of maybe 3:1 because those are advertised with the systems but what I didn't know was how much that waste amount increased with age.

It could be running continuously because it's never fully filling the system up or the ASO valve has failed like you mention. We're getting very little water from the system now. Like pull out 16 oz and it's dribbling by the end of filling that first glass then wait 20 mins and get another few ounces out.

I'll look at the shutoff valve to see if it's easily replaceable or not. I may be able to solve this for the price of a few parts and a new membrane and filter set. That would be fine with me since it's around 1/3 to 1/2 the price of a new system.

Thanks I was looking at some of the iSpring systems. They look decent and priced reasonably.

As mentioned, either get something with a standardized filter, or something that can be sourced locally.

There's really not much on them to go bad, so you should be able to repair your existing system.

$7.99 on Amazon for a replacement ASO seems like a cheap way to test, and possibly salvage your system.