Osmolator sensor issue

[alin2]

I used a Osmolator for several years with my old tank set-up without any issues. I purchased a new osmolator for my new tank set up.

However, I'm getting a strange problem with the optical sensor (not the overflow float switch).

The optical float switch is currently underwater, but the controller randomly turns on the yellow fill light and activates the pump. The pump will stay activated for minutes until I tap or wipe the optical sensor with my finger underwater.

There are no bubbles in the sump chamber where the optical sensor is located. The water level is stable and the optical sensor is currently underwater (due to an overfill from the osmolator)

Everything else works fine. The pump works and the float switch activates the alarm. I can get the controller to switch to "green" by tapping or wiping the optical sensor underwater. but, within 10-15 minutes, the yellow light turns on.

I disconnected the pump and returned in a couple of hours. The red light was on yet the optical sensor was still underwater.

Any thoughts? Never had any issues on my old tank...

 

[rvitko]

This is with a new osmolator or the old one? The usual cause of this is bubbles and a new sensor has a very strong affinity for bubbles, plastic being made of oil, repels water and air clings to it, over a few days of use this issue dissipates. The other likely culprit is the capacitor that provides the power to the optic sensor. They sometimes fail and then the optic sensor doesn't get enough power, but this would be odd on a new unit, but not impossible.

 

[alin2]

Hi Roger:

Again, thanks for the prompt response...I just don't know how you do it...

It's with the new one. I did notice the new sensor was black and looks different than the one I bought four years ago.

I don't think it's a capacitor problem in the controller since it seems to show "green" when I tap or wipe the sensor underwater.

So, any other tricks with the new sensor? Just leave it along for a couple of days?

Thanks,
Al

 

[detour]

I do not have an old sensor or unit to compare to, but am having a simular issue with a new one setup with a new tank. The LFS did indicate that the sensor should sit in the salt water for about a week before we activated the unit. It has been a week, and when first using it, ran into the issue with air bubbles - so I've moved it from the location the LFS installed it (it was a LFS delivery and installation).

Tonight, the float cut-off alarm woke me up....after the unit continued to pump enough water to raise the level to engage the float. Visually, I didn't see any air bubbles on the sensor. And after cleaning and re-adjusting my skimmer for the excessive water level, am on line trying to find some direction as to what to try next (with the power disconnected from the controller).

Thanks!

 

[alin2]

I ended up cleaning the optical sensor with some vinegar. It's been working great ever since then.

 

[rvitko]

Detour, are you sure the pump was running and it did not siphon the water into the sump? Did it go past the float r just until the float was raised? If you have a larger reservoir and the top off water is pumping to the sump, it will siphon until the reservoir level is equal to the sump level.

 

[detour]

I'm pretty sure the pump was running, as the resevoir was nearly empty (2.5 gallon container) - well below the water level in sump.

I've since remounted the sensor and float on separate brackets (versus stacked on one), wiped the sensor, cleaned it with vinegar - and with it completely submersed, plugged the power cord back into the controller. The yellow and green lights came on at start up, along with the pump. And, my RO resevoir is for the most part, empty now - so it will need to wait until I get more before I continue to troubleshoot/test.

Other ideas?

 

[rvitko]

It is not unusual for both lights to come on and the pump to run very briefly on start up. If it is not air bubbles, or a siphon, it is likely a defect.

 

[detour]

Picked up more RO water from the LFS today. Will wait until it is low again and try it (meanwhile, the sensor is attached to the hanging strap, but the strap is just sitting in the water, keeping the sensor wet.).

When I try it, I'll hang the hanging strap (or hold it in place) and let it start up to see what happens.

The LFS thinks it just might be a touchy sensor to get set up initially. I'll give it a few more days and see if it resolves.

Regarding the siphon - is it the level of the water in the sump, or the level of the water feed tube to the sump that is the measure of water height in comparison to the resevoit height? In other words - my water tube is secured near the top of the sump, and angled down a bit to pour into the ater below it. Even when full, my resevoir should be below the height.

Thanks!

 

[rvitko]

The optic sensor is very sensitive and cannot differentiate between air bubbles and being dry.

As far as a siphon is concerned, the end point of the two hoses is the issue. If the hose at the the sump is below the hose in the reservoir, it will siphon until the equal point between the hose end and reservoir is reached.

 

[livingstone]

I sure do appreciate this Tunze forum. I had this "sensor failure" problem yesterday but I'll bet it was bubbles. Thanks Roger!