Trunze 3155 problem?

[Fishyj]

Hi all, I have a fusion 20 aio tank that had a sensor and float setup. The controller I had died on me and the tank would not top off. I ended up buying a trunze 3155 ato and in the beginning had no problems. Now the unit is overfilling the tank. I know the filters were somewhat dirty, took them out and the water level in the back went up to almost alarm state on the ato. Could it be the return pump or am I overthinking this completely. Can a slightly dirty filter me the cause? I never had this problem with my other setup before it quit. Any suggestions or ideas greatly appreciated.

 

[Opus]

Try cleaning the sensor on the Tunze.

 

[Water Dog]

When it’s overfilling, is it a result of power cycling the unit on and off? Upon restart due to restoring power to the 3155, no matter where the water level is in relation to the sensor, the unit will automatically fill for 15 seconds. When using the 3155 in Nano and AIO tanks, it’s a good idea to open up the 5017 controller box and turn the red potentiometer knob inside all the way counter clockwise to the nano setting to slow the pump speed to its minimum setting. Not sure if this is why you're experiencing overfilling issues but I thought it was worth a mention.

 

[Fishyj]

Thanks for the help. I will try both things.

 

[PR_nano]

I also have a IM20 and recommend what @Water Dog suggested, as to set the controller on nano.

Also where is your top off line going? It should be the same chamber as the sensor. I had a similar issue when the ATO line went to the first chamber but the sensor was in the middle chamber.

 

[pmarsh44]

Had the same issue happening to me. Could not figure out what the heck was wrong until I realized that the power was indeed cycling when I was not around, overnight, at work etc.

My culprit turned out being a heater that was starting to malfunction. Replaced the heater and the mysterious overfilling went away.