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Ideas?? Dema Injector Issue

traveler17

Well-known member
So I have a dema injector that I run Total Shield in a low pressure pass. Has run a year w no issues. Just noticed today the draw line had no chemical in it. Turned it on and no suction/draw with hose off of the barb. Have 2 new ones on the shelf and tried both with still no draw. Asco valve is running as should and putting water through the manifolds, just not drawing chemical. Tried turning pressure up on pump and opened up the metering screw all the way and still no luck. Anyone ever have this issue or have any ideas? I’d appreciate the help. Thanks!!
 

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Sounds like you have restriction further up the line causing a back pressure which will cause the venturi not to pull chemical in, is there a check valve at the end of the line that goes into the bay?
 
Sounds like you have restriction further up the line causing a back pressure which will cause the venturi not to pull chemical in, is there a check valve at the end of the line that goes into the bay?
Actually yeah there is a check valve that the line goes to on the wall manifold, it’s the only one I know of. Very annoying if that’s it. lol. I looked at it today and said no not the problem. Thanks. I’ll swap it out first thing in the AM
 
This is kind of basic and obvious but.......Is the foot valve working and not all gummed up? Make sure it flows freely up through the foot valve through the line to the injector
 
I agree it definitely should be obvious but the line is not attached to the injector. I should feel a draw without it hooked up. Foot valve in the chem tank not the issue
 
We just had almost the exact same issue on our kondor that uses the same dema. One of the other solenoids were bad and causing water to go through it when the wax application was on. Pull all the hoses and be sure no other solenoids are leaking. When the dema asco is energized.
 
We just had almost the exact same issue on our kondor that uses the same dema. One of the other solenoids were bad and causing water to go through it when the wax application was on. Pull all the hoses and be sure no other solenoids are leaking. When the dema asco is energized.
Thank you for something else to try. Appreciate the advice!!
 
We just had almost the exact same issue on our kondor that uses the same dema. One of the other solenoids were bad and causing water to go through it when the wax application was on. Pull all the hoses and be sure no other solenoids are leaking. When the dema asco is energized.]
 
Sounds like you have restriction further up the line causing a back pressure which will cause the venturi not to pull chemical in, is there a check valve at the end of the line that goes into the bay?
Tried the check valve swap and still nada. Thanks for trying anyway!!
 
Thanks Dakota. I did exactly what you recommended and there was a leak on the 1st presoak valve. Put a new one on and still no luck. Thought for sure that was going to be the issue. Thanks for the input and if you tried anything else before that I’m all ears. Thanks again[/QUOTE
 
Sounds like maybe there is a problem with the electrical where it energizes the valve to open. Can you swap the coil with one that you know works on the manifold and see if that gets it to operate?
 
Sounds like maybe there is a problem with the electrical where it energizes the valve to open. Can you swap the coil with one that you know works on the manifold and see if that gets it to operate?
So I took the end of the line out of the wall manifold and turned on the wax option and had really hard pressure coming out of the valve. just so I’m understanding this doesn’t that mean the asco valve is working correctly??
 
When you replaced the DEMA injector di you replace the complete injector or just part of it? Also did you check the new injector to be sure it has a nozzle inside the injector, when you buy them new they sometimes come without an injector nozzle inside, there should be 3 nozzles inside the box when new. Inside the brown plastic piece that the chemical hose connects to there is a small white ball and spring, make sure the ball is moving freely, it acts like a check valve. If you have water going though the ASCO valve you should have chemical going though the DEMA injector.
 
When you replaced the DEMA injector di you replace the complete injector or just part of it? Also did you check the new injector to be sure it has a nozzle inside the injector, when you buy them new they sometimes come without an injector nozzle inside, there should be 3 nozzles inside the box when new. Inside the brown plastic piece that the chemical hose connects to there is a small white ball and spring, make sure the ball is moving freely, it acts like a check valve. If you have water going though the ASCO valve you should have chemical going though the DEMA injector.
Thanks Randy, so yes I replaced the entire injector and inserted the same size bushing as the one that “failed”. I had 2 new ones on the shelf and tried both. I took one new apart and the old one just to look inside. I did replace one presoak asco valve this morning that was suggested to check that was opening “leaking” when I turned on the sealer wax option. Hoped that was the problem but no luck. Even turned pump pressure up and still no draw. It’s making me mental, this was supposed to be an easy fix :) , thanks for the suggestion and if you have any other something to try I’m listening. Thx again
 
Try this temporally, remove the white ball and spring from inside the black plastic injector block and see what happens.
 
Try this temporally, remove the white ball and spring from inside the black plastic injector block and see what happens.
Tried that this morning Randy and water shot out of the injector block. I was going to put a green injector on and see what happens. Running out of thing to try :)
 
I just swapped it w a hydra flex injector and it’s pulling fine now. Not sure why 2 different brand new demas didn’t work unless they were both faulty. Thank you to anyone who tried to walk me through this issue!!
 
Is the green hydra flex injector the same GPM as the Dema?
the dema has a flow rate of 3 to 36 gpm. The hydra flex I just ordered has a flow rate of 5.5 gpm. If it’s not enough I’ll put it on the shelf and put the dema back on unless you have another suggestion. I’m just not understanding why I couldnt get the 2 new ones to work. Gotta be a fluke but they were both faulty. Attached them to a presoak and nothing
 
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