ATO Trouble

[markysgirl]

I have a Tunze ATO and got it all hooked up according to the directions that came with it.
I turned it on and it filled to the desired level just like it is supposed to.
Then 5-10 minutes later it started running and ran until the "too high" alarm came on.
I unplugged it and went on with my life because ain't nobody got time for stuff that doesn't work right.
A couple of days later when I had more time, I checked to make sure everything was hooked up correctly, and plugged it back in.
It again, filled the sump to where it should and just stayed there this time.
Sweet.
I went to bed only to be awakened by my husband telling me the alarm was going off.
So I trudged downstairs in the middle of the night to unplug it again.
Does anyone have any advice for this noob who is pretty frustrated with their ATO?

 

[dank reefer]

Where do you have the sensor located? Tank or sump?

if its in the sump area, just make sure that the water level is not rising and falling on its own.

 

[SPR1968]

Just a basic to eliminate, but have you checked for siphon effect. The reservoir must be lower than the outlet on the Tunze hose or it will siphon.

Also what size is your tank because it has 3 power settings inside it. nano, medium and large and this affects the fill rate/power

Also as said by Jose, it might be as simple as raising the backup float switch a little if your sump level fluctuates. I have to do that

 

[Water Dog]

In addition to making sure you aren’t experiencing a siphoning effect, when setting up a new 3155 ATO, make sure there is no microbubble build up on the optical sensor. Just wipe them off with your fingers as the microbubbles will make the sensor go a bit wonky. The microbubbles will normally go away once a biofilm develops on the sensor.