Drain hose discharging non-stop on reverse osmosis system

[paperpusher]

I have a 5 stage reverse osmosis system i my basement.

Yesterday, the drain hose sprung a leak. The drain hose runs a good 4 feet and then connects to a 1/4 turn valve, which has another 4 foot hose going into the basement drain hole. Do not even understand the logic why they would have a valve in the middle of a drain line just leading into a drain.

Anyway, I shut off the valve and the leak of the hose above the valve immediately stopped. Also, I noticed that the filtered water faucets on the kitchen sink and wet bar went dry after shutting of this valve - strange as this is just a drain line.

Went to HD and picked up a new vinyl hose. Plugged it in but could not connect it to the terminal part of the drain line as I realized that the previous istaller had used a copper ferulle ring on a vinyl hose. I was going to first buy a plastic ferulle. Anyway, for last night, I just ran a plain vinyl drain hose, without any valve i the middle, all the way to the drain hole and the hose keeps draining non stop and no water is coming out from the kitchen and wet bar drinking water faucet. How can a drain hose affect the water supply?

 

[Diehard]

It sounds like you are totally unfamiliar with the operation of your system. You shouldn't be making changes based on your assumptions.

Your quickest way to get an answer to your questions is to simply call the manufacturer and ask them.

 

[Mitchell-DIY-Guy]

@Diehard is right, call the manufacturer, get the owner's manual and schematic.

That being said, if this is one of those small 5-stage units like an undersink unit that looks something like this:

Then the way they work is this: your city water pressure (or your well pump tank) pushes the cold water through a three-stage filtration system (generally a sediment filter, a pre-carbon contaminant filter, and a carbon filter) before this cleaned water is pushed against the RO membrane. On a small system like this, this is a very slow process, literally drop by drop. The water exits the membrane and goes to a final polishing filter for taste; the membrane and the polish filter sit on top of the unit; they are the two horizontal things... RO is very inefficient; for each drop of RO water you make, one goes to drain. Thus, as this water pressure on the input side is pushing very hard against the membrane, it's taking a long time to fill that pressure tank. Thus, you will be sending water to drain for a while.

These small units w/o a pump will generate 30-50 GPD; that's maybe 1.25-2.0 gallons per hour. Thus it will take anywhere from 30-60 minutes give or take, to fill that 1-gallon tank. Thus, your drain will be dripping that entire time, and longer if you use any water in the interim...

BTW, I've had one for over 20 years, they have not changed much. This past summer I totally rebuilt mine, changing all the lines to PEX. I also thoroughly cleaned all the filter housings--man were they NASTY inside. The final polish filter was a throwaway. Scrubbed them clean and disinfected them too. Yuck.