3155 ATO Sensor Problem on Start-up

[RCS82]

Hi there,

Having a problem with my sensor. Bought the unit new maybe 6 months ago and it seemed to work fine for a few months but now I can not get it to work properly. My tank is around 60 gallons so I changed it to nano inside the controller. Have cleaned the sensor and dried it. But can not get it to start up correct. It will fill and go past the sensor on startup and trigger the high water float. When I plug in the power it beeps and gives a green light and starts filling, but just keeps filling. On startup I leave it dry and out of the water. My confusion is maybe about how high to leave it or should it be submerged a bit?

Thanks for any feedback.

 

[rvitko Verified Sponsor]

Does this tank have a small built in compartment? When you plug it in, regardless of water level unless the float is raised, it is going to run the pump 20 seconds and in the nano setting add about a 1/2 cup of water. It always runs the pump on start up as a test. Is this possibly the culprit?

 

[RCS82]

Does this tank have a small built in compartment? When you plug it in, regardless of water level unless the float is raised, it is going to run the pump 20 seconds and in the nano setting add about a 1/2 cup of water. It always runs the pump on start up as a test. Is this possibly the culprit?

The sensors are in a regular sump in the return section, nothing out of the ordinary. When I plugged it in yesterday with the sensor dry and well above the water line, it ran for 2 minutes until I unplugged it again.

 

[rvitko Verified Sponsor]

In the 2 minutes had it reached the optic sensor or not, was the sensor submerged? It can run up to 10 minutes if needed to reach the level on the optic sensor. Here is everything I know of that can cause this-

 

[Fishingandreefing]

Mine failed and dumped an entire bucket of rodi mixed with kalk. Since then I had a mini crash and lost quit a few nice acro. It’s being over few months, still hasn’t recover. I now added another sensor to shut it down if it’s overfill. I don’t trust Tunze.

 

[EeyoreIsMySpiritAnimal]

I prefer the 3152, even on a larger tank.

 

[rvitko Verified Sponsor]

There is only one way this can happen, a siphon, unless the float install was messed up, between the optic sensor, the float and the 10 minute time limit (roughly 2 gallons), there is no scenario where this can occur if it is properly installed, siphon situation 3 is your likely culprit, the hose must end above your reservoir water level.

 

[RCS82]

I'll place the dry sensor just above the water and see if works. I've done this before, tried multiple scenarios, sensor at water line, moving the sensor from dry to below the water line etc.. Yesterday I put it just above the water and plugged it in. It beeped and green lighted and start to fill til it reached the sensor and shut off. But maybe 10 or 20 seconds later if turned the pump on again and filled it til the high water float alarmed.

 

[EeyoreIsMySpiritAnimal]

I'll place the dry sensor just above the water and see if works. I've done this before, tried multiple scenarios, sensor at water line, moving the sensor from dry to below the water line etc.. Yesterday I put it just above the water and plugged it in. It beeped and green lighted and start to fill til it reached the sensor and shut off. But maybe 10 or 20 seconds later if turned the pump on again and filled it til the high water float alarmed.

But where is the end of the tube compared to the water level in your ATO container?

 

[rvitko Verified Sponsor]

The optic sensor only detects if it is in contact with something reflecting the light or not, air bubbles accumulating can cause it to act like it is dry, a wire or debris on the sensor tip can cause it to act like it is wet. In all cases though, the float is a full override and would shut it down as would the 10 minute time limit. It is possible there is something wrong with the sensor, but a positive and negative confirmation from the test in the PDF would generally rule that out. Can I get a photo of how the sensors are mounted?

 

[Fishingandreefing]

I prefer the 3152, even on a larger tank.

There is only one way this can happen, a siphon, unless the float install was messed up, between the optic sensor, the float and the 10 minute time limit (roughly 2 gallons), there is no scenario where this can occur if it is properly installed, siphon situation 3 is your likely culprit, the hose must end above your reservoir water level.

My rodi line is a well above my 5G bucket, so I don’t know how if siphoning was the issue.

 

[RCS82]

The optic sensor only detects if it is in contact with something reflecting the light or not, air bubbles accumulating can cause it to act like it is dry, a wire or debris on the sensor tip can cause it to act like it is wet. In all cases though, the float is a full override and would shut it down as would the 10 minute time limit. It is possible there is something wrong with the sensor, but a positive and negative confirmation from the test in the PDF would generally rule that out. Can I get a photo of how the sensors are mounted?

 

[RCS82]

The optic sensor only detects if it is in contact with something reflecting the light or not, air bubbles accumulating can cause it to act like it is dry, a wire or debris on the sensor tip can cause it to act like it is wet. In all cases though, the float is a full override and would shut it down as would the 10 minute time limit. It is possible there is something wrong with the sensor, but a positive and negative confirmation from the test in the PDF would generally rule that out. Can I get a photo of how the sensors are mounted?

First thing, do you start with the sensor above the water or below the water?

 

[rvitko Verified Sponsor]

First thing, do you start with the sensor above the water or below the water?

This does not matter, but you have to keep in mind it is always going to run 20 seconds on power up, so if your optic sensor is in water and you don;t have a small chamber, this addition can raise the float.

 

[rvitko Verified Sponsor]

My rodi line is a well above my 5G bucket, so I don’t know how if siphoning was the issue.

Is the end of the hose above the water line in the reservoir? All that matters is A is above B, if the hose loops up at some point, this will not stop a siphon. Are you using the included pump or a solenoid? If you are using a solenoid as you mentioned RODI, then yes, this can happen because solenoids will innevitably fail, if you use a solenoid, you must have extra redundancies, they tend to jam open eventually. The float circuit is a completely seperate redundant circuit and if the optic sensor fails the float can override it, if this were stuck for any reason, the 10 minute timer will stop it, if the controller has a short it would show the water damage indicator and refuse to run. The only things that can cause a gross overfill if using a pump, is some sort of power cycling, which resets the timer combined with an inoperable float because it is stuck or affected by a magnet and a failed optic sensor, or a plumbing issue such as a drain that clogged or is surging so water was added then the drain frees up and the water returns, or a siphon.

 

[rvitko Verified Sponsor]

This compartment is quite small, since all added water goes to this last chamber in a properly plumbed set up, I suspect that it could just be the 20 second fill on start up. If it only takes about 1/2 cup to raise the float, that would be the most likely culprit, What does the extra red pipe do that is not connected to a pump?