IM Hydrofill stuck on?

[Nem0]

I purchased a second-hand ATO from someone on this site and it seems to be stuck on. Trying to troubleshoot. I placed one sensor below water level, one right at water level. When I take water out, it will register the drop and the pump will turn on. However, it doesn't seem to stop...even after 10 min when both sensors are completely submerged. BUT when I unplug the ATO (with the water level the exact same) and plug it back in, it recognizes the water level and doesn't pump any more water in. Any ideas?

 

[Mjrenz]

I purchased a second-hand ATO from someone on this site and it seems to be stuck on. Trying to troubleshoot. I placed one sensor below water level, one right at water level. When I take water out, it will register the drop and the pump will turn on. However, it doesn't seem to stop...even after 10 min when both sensors are completely submerged. BUT when I unplug the ATO (with the water level the exact same) and plug it back in, it recognizes the water level and doesn't pump any more water in. Any ideas?

What kind of ato is it?

 

[Nem0]

What kind of ato is it?

IM hydrofill

 

[Mjrenz]

IM hydrofill

I'm not familiar with that one but I'll see if I can figure something out for you

 

[Mjrenz]

I looked at the manual for it, when the second sensor is submerged does the single led on the right light up solid?

 

[Nem0]

I looked at the manual for it, when the second sensor is submerged does the single led on the right light up solid?

no, it only says "low" which is the middle sensor

 

[Mjrenz]

I would suspect that it could be a bad sensor or it doesn't have a good connection. Can you swap the location of the sensors and see if it works?