Why did my return pump turn ON but not OFF?

Phyber · Jul 29, 2019

The other afternoon I was in the living room and heard my Tunze ATO alarm going off due to high water level in the sump. Went to check it out but water was down to a normal level, however I saw some air bubbles comeing out of the return line, indicating that at some point it had turned off.

I checked the event log and found a random "ReturnPump ON" event but there was no corresponding OFF... I also never had an alert for an event such as high temp, etc. (my tank stays well below my high temp threshold).
I worry that this will happen when my babysitter is home and she not know what to do... Can you explain what happened?

Ox100 · Jul 29, 2019

Sounds tricky I would try and get it replaced before it happens agai with something else this is some kind of malfunction if that wasn't programmed

landlubber · Jul 29, 2019

I have an apex and a tunze ato and there are only 2 things I can think of... you possibly hit the feed timer which gives the tank 5 mins without pumps and then starts with short low-level chime or a small power interruption killed the return for a few seconds allowing water to drain back tripping the ato then it started again and caught back up. tough to say for sure without it showing an event in the apex's history.

Phyber · Jul 29, 2019

Ox100 said:
Sounds tricky I would try and get it replaced before it happens agai with something else this is some kind of malfunction if that wasn't programmed

The pump or EB8? The pump is a brand new sicce that has been working fine. The EB8 is new to me but has been working fine for a little over a month on its own.

landlubber said:
I have an apex and a tunze ato and there are only 2 things I can think of... you possibly hit the feed timer which gives the tank 5 mins without pumps and then starts with short low-level chime or a small power interruption killed the return for a few seconds allowing water to drain back tripping the ato then it started again and caught back up. tough to say for sure without it showing an event in the apex's history.

Hey! We were watching a movie so it definitely wasn't me that triggered a feed mode. I'll check the amp log for the EB8 during that time. Just weird a random ON was sent, made me think there was some hysteresis setting I overlooked but I checked and it wasn't.