RODI Help

[Kate Vellis]

My Aquatic Life Twist-In RODI system won't run. A week or so ago, the waste water slowed down to a drop every few minutes, but the output was still running at 0 TDS. Then the TDS started creeping up. I replaced all 4 of the cartridges, and now I get nothing. The water fills the sediment cartridge and runs into the carbon block, and even a little into the RO cartridge and a little into the DI cartridge, but nothing comes out of the waste line or the RODI line. The pressure builds up in the cartridges so that it pops and spews water when I disconnect the cartridges. I did not assemble the system initially, and I don't know if and where there are check valves. I am hoping that someone can get me back in business making RODI water.

 

[Kate Vellis]

My Aquatic Life Twist-In RODI system won't run. A week or so ago, the waste water slowed down to a drop every few minutes, but the output was still running at 0 TDS. Then the TDS started creeping up. I replaced all 4 of the cartridges, and now I get nothing. The water fills the sediment cartridge and runs into the carbon block, and even a little into the RO cartridge and a little into the DI cartridge, but nothing comes out of the waste line or the RODI line. The pressure builds up in the cartridges so that it pops and spews water when I disconnect the cartridges. I did not assemble the system initially, and I don't know if and where there are check valves. I am hoping that someone can get me back in business making RODI water.

Is it possible that the cartridges are the wrong size? I have a 100 GPD system and the cartridges are for the 75 GPD system.

 

[ScubaSkeets]

Can you check to see if the waste line is not crimped or blocked somehow? Kinda same thing happened to me and it was that.

 

[Kate Vellis]

Can you check to see if the waste line is not crimped or blocked somehow? Kinda same thing happened to me and it was that.

Yeah, I just looked at the system again, and I can't see that the waste line looks bent or crimped at all. I'm wondering if there is some crimp inside the plastic piece that connects the waste line at the back of the RO cartridge. I just don't know how to take it apart, and I don't want to force something apart that isn't supposed to be taken apart. I'd really love to see a schematic of the tubing inside the connections.

 

[ScubaSkeets]

There's a check valve between the RO membrane and the waste line. At least I assume it's a check valve because it has a direction of flow arrow

 

[Gtinnel]

That not a check valve, it’s a flow restrictor. A rodi unit has to put a restriction on the waste side to cause enough pressure get water to flow through the filtered side.
I’m not sure what your problem is but without that restrictor all off your water should flow out the waste line.

I am not familiar with these systems but with water not flowing out either side it has to be something blocking its path inside the unit. None of the filters had some kind of plastic film that didn’t get removed do they.

 

[dowdalld]

If your unit has a mechanical shut off valve, looks like a cube with 4 ports, it could be stuck closed, dismantle and clean. If its a pumped unit with a solenoid valve that may be failed closed.

 

[Kate Vellis]

That not a check valve, it’s a flow restrictor. A rodi unit has to put a restriction on the waste side to cause enough pressure get water to flow through the filtered side.
I’m not sure what your problem is but without that restrictor all off your water should flow out the waste line.

I am not familiar with these systems but with water not flowing out either side it has to be something blocking its path inside the unit. None of the filters had some kind of plastic film that didn’t get removed do they.

No, the unit was working fine for over 2 years. Then the waste water decreased to drops and about a week later the TDS started increasing. That’s when I changed the cartridges.

 

[Kate Vellis]

There's a check valve between the RO membrane and the waste line. At least I assume it's a check valve because it has a direction of flow arrow

Some how the check valve was stuck. I was able to open it with a knitting needle and now I’m back in business. I appreciate the suggestions.

 

[Kate Vellis]

If your unit has a mechanical shut off valve, looks like a cube with 4 ports, it could be stuck closed, dismantle and clean. If it’s a pumped unit with a solenoid valve that may be failed closed.

Thanks for the input. I have a very simple system. There was something blocking the check valve out of the RO into the waste. It’s running again