RODI may be broken, please help diagnose

I have a AWI extreme 3.
Yesterday I went to get some water out of it to mix up some buffer and it was just dripping.
I found out that the waste water tube was being blocked by another blockage in my sink drain where the waste tube drains to.

I cleared the blockage, and disassembled the ASOV to clean it. I dumped and cleaned out all 5 stages of debree, and I checked all the tubing for clogs.

When I started it back up again, the waste water kept on flowing. The 3rd and 5th stage seemed to not completely fill up with water and there is a constant flowing sound like a hiss. It almost sounds like air, but I am unable to locate a leak.

Is it the ASOV?

 

Take the unit in your hands while you have it operating and turn it upside down and in all directions to release all the air trapped inside. This usually works.
If the waste line was plugged for long your membrane may be wasted. Once you have it running for an hour or so test the RO only TDS to make sure it is still close to 98% rejection, if not you probably fouled the membrane with reduced/no waste flow. Keeping the waste ratio at 4:1 is critical as that is what flushes the membrane continously.

NEVER EVER, let me repeat NEVER shove the waste line down a drain. Not only does this violate plumbing codes, it is a direct cross connection between the sanitary sewer and your drinking water system. Always leave the waste line suspended so water drips down and you have an air gap so no waste can back up. I have mine screwed to the back of my laundry sink with a small nylon cable clamp like they attach the cable TV coax to your house trim with. It is above the high water line in the sink so can never be submerged.

 

Learn something new every day. Time to go pull a waste line out of a drain.

 

If you have ever see a drinking water RO system with what they call an "air gap Faucet" this is the reason behind it. The waste line actually connects to a nipple under the faucet then travels back down to the drain saddle so you have a high point, open to atmosphere which provides physical seperation between the samitary sewer (sink P trap in this case) and the potable water. Faucets that do not hav an air gap do not meet Uniform Plumbing Codes and cannot be installed legally in most municipalities.

Here is a little wrire up I found on how they work.
How Air Gap Faucets Work