Osmolator 3155 Pump not always activating

[reely989]

So, I love the 3155, but the last few days, it has sporadically not triggered the pump to top off the tank. The sensor is working because it shows water low, but the pump isn’t activated. If I unplug it and plug it back in, it works fine. Any easy troubleshooting, or should I go for a new pump?

 

[Reefing.with.Rich]

So, I love the 3155, but the last few days, it has sporadically not triggered the pump to top off the tank. The sensor is working because it shows water low, but the pump isn’t activated. If I unplug it and plug it back in, it works fine. Any easy troubleshooting, or should I go for a new pump?

I had the same problem years ago and couldn’t find a fix so I upgraded to a different ATO completely

 

[reely989]

I had the same problem years ago and couldn’t find a fix so I upgraded to a different ATO completely

Hopefully I have better luck! Which ATO did you go with?

 

[Reefing.with.Rich]

Hopefully I have better luck! Which ATO did you go with?

Tried the reef breeder because brs had a sale on it and plan to upgrade again lol. The sensors are way to spread out and I’d rather my water not drop so much before triggering on to fill it up. Can’t wait for Red Sea to drop their ATO because I will for sure that one

 

[Fishingandreefing]

two times I got an entire bucket of ato mixed with kalk dumped into my tank. Lost some corals, definitely don’t trust it 100%

 

[rvitko Verified Sponsor]

If the too low light is on, which is a red light, that means the pump ran 10 continuous minutes, or at least was triggered to run. This would either mean the system is more than a couple gallons low, the pump is air locked and cannot prime (tip it upside down while submerged), or the pump is failing, it can also be the hose is kinked or clogged but this typically only would happen if the top off water is used for carbon dosing or kalk.

 

[rvitko Verified Sponsor]

two times I got an entire bucket of ato mixed with kalk dumped into my tank. Lost some corals, definitely don’t trust it 100%

Check these causes, especially siphon situation 3, it is otherwise virtually impossible to defeat the optic sensor, back up float and pumping time limit, if you found the float completely submerged and this issue tends to happen only after you refilled your reservoir, it is most definitely a siphon, in some rare cases a plumbing issue can cause this, for example the drain is clogged or obstructed, the sump was low for a while, a top off occurred the obstruction cleared, but one of the main advantages of the Osmolator is complete redundancy, the float system is an analog circuit that can cancel a digital circuit and it is nearly impossible to defeat every safety outside of an installation error.

 

[reely989]

If the too low light is on, which is a red light, that means the pump ran 10 continuous minutes, or at least was triggered to run. This would either mean the system is more than a couple gallons low, the pump is air locked and cannot prime (tip it upside down while submerged), or the pump is failing, it can also be the hose is kinked or clogged but this typically only would happen if the top off water is used for carbon dosing or kalk.

I’ll try tipping the pump upside down. The other explanations don’t really seem to make any sense in my case. Hopefully that will fix it. Though, I’m not sure because I wouldn’t think it would be able to prime by just unplugging it and plugging the unit back in right? It works after I restore power every time.

 

[rvitko Verified Sponsor]

If the pump has air trapped in it, which will tend to happen any time it has been out of water, it will not be able to purge the air and draw in water, once the air bubble is out, it will work normally. If it is indeed just the red too low light by itself and it takes 10 minutes to come on, the issue is somewhere with the pump/tubing or a very sump level at the start.

 

[EeyoreIsMySpiritAnimal]

I’ll try tipping the pump upside down. The other explanations don’t really seem to make any sense in my case. Hopefully that will fix it. Though, I’m not sure because I wouldn’t think it would be able to prime by just unplugging it and plugging the unit back in right? It works after I restore power every time.

You unit might be set to keep power off after it runs for 10 minutes, in which case, you do need to manually reset it (power off and then on again.)

FWIW, I chose the 3152 (nano version) for my new tank (140 gallons) based on reviews that said the single sensor had less problems than the 3155 dual sensors. I've had a nano on my original tank (90 gallons) for over 7 years - no issues other than replacing the pump once (but the ato was used when I got it). Regularly check the float valve for critters and otherwise it's pretty much maintenance free.