3155 sensor is going faulty

[Caliguy1983]

I’ve had a 3155 installed on my system for 3 years with very little issues. Lately it’s been acting up. I checked the sensor and it’s clean, no wire in the way. It let my pump chamber in the sump nearly run dry one day. I turned the power on and off and it seemed to reset itself and start working again. Just got home from Christmas dinner with my in-laws and I checked on the tank and had the opposite problem. My sump was nearly overflowed! The Tunze was pumping past the emergency float level. Had I not caught this I would have had a disaster as I have a ton of high end sps ... I’d say it pumped 10 gals of fresh top off into the tank today. Dropped my salinity severely and I may still not be out of the woods...I purchased this product because I thought it had a great safety feature but obviously it’s not fail proof. I don’t trust this top off anymore and I’m afraid to buy another one. I hope Roger can help.

 

[Hersheyb]

was there an alarm when the float valve was elevated?

 

[Caliguy1983]

was there an alarm when the float valve was elevated?

No it pumped some water right in front of me I was shocked it didn’t kill it

 

[rvitko]

Is the refugium light new? Optic sensors use infrared, well made refugium lights use infrared, it is critical the optic sensor is not near a refugium light. In general pumping past the float should be all but impossible, are you sure you have not rerouted your tubing or changed the reservoir so you set up a siphon. The end of the hose at the sump or main tank absolutely has to be above the water level in the reservoir to avoid siphoning. Besides a siphon the only other common cause of a float switch defeat is electromagnetic interference, new electronics are suspect, especially any that make contact with a component or wire of the 3155, and any new magnets near the sensors are suspect.

 

[moreef]

Wow I have also had failures of sensor to pump water but this is first I have heard of overfill float switch not turning off pump. Guess I have to go test mine.

I just got a magnetic float switch holder that will be here soon and plan to have one on bottom of sump hooked up to breakout box to kill return pump if it runs dry. Anything mechanical will eventually fail so we have to add barriers to alert us and protect out equipment etc.

 

[Caliguy1983]

Is the refugium light new? Optic sensors use infrared, well made refugium lights use infrared, it is critical the optic sensor is not near a refugium light. In general pumping past the float should be all but impossible, are you sure you have not rerouted your tubing or changed the reservoir so you set up a siphon. The end of the hose at the sump or main tank absolutely has to be above the water level in the reservoir to avoid siphoning. Besides a siphon the only other common cause of a float switch defeat is electromagnetic interference, new electronics are suspect, especially any that make contact with a component or wire of the 3155, and any new magnets near the sensors are suspect.

I’ve used the same fuge bulb for 4 years. The sensor hasn’t moved and nothing has changed for 3 years. Like I said no issues whatsoever up until it going haywire this week. All I’ve ever done is clean it and put it right back in the same place on my return pump chamber. There’s no siphon as the container for the ATO is on the ground the top of the tank is much higher and the hose doesn’t even touch the water. I’m baffled as to why this is going on . I added radions about a month ago but they aren’t close to any of the Tunze parts .... it’s not like I’m a new customer I’ve had this set up flawless for 3+ years now.

 

[Caliguy1983]

 

[Caliguy1983]

I will go back and follow all the wires from the sensor in sump to the control box just make sure nothing is on them but I’m 90% sure nothing even touches them back there.

 

[Bossman]

If both sensors have failed I would suspect the controller itself. I have had -2- controllers go bad on the 3155. The flashing lights indicated water infiltration. One was inside the cabinet and could have had drips of water fall on it. The other most likely not.

I have them on 4 tanks with 2 running kalk. No pumps have failed with the oldest at 2 years old.

 

[Caliguy1983]

If both sensors have failed I would suspect the controller itself. I have had -2- controllers go bad on the 3155. The flashing lights indicated water infiltration. One was inside the cabinet and could have had drips of water fall on it. The other most likely not.

I have them on 4 tanks with 2 running kalk. No pumps have failed with the oldest at 2 years old.

yeah there’s no water dripping on my controller I suspected it was the culprit by the randomness of the pump and the fact that the float didn’t work. My sensor is clean and no other wires are touching the Tunze wires. I don’t trust this unit anymore. Will see what Roger says but I’m guessing I’m out of warranty.

 

[Caliguy1983]

Just looked it up in my BRS order history. I purchased it 9/22/2017 it failed 3 months out of warranty. Tanks been up longer I thought I had installed it with the tank but I guess I’ve only had it up 2 years 3 months

 

[rvitko]

Wow I have also had failures of sensor to pump water but this is first I have heard of overfill float switch not turning off pump. Guess I have to go test mine.

I just got a magnetic float switch holder that will be here soon and plan to have one on bottom of sump hooked up to breakout box to kill return pump if it runs dry. Anything mechanical will eventually fail so we have to add barriers to alert us and protect out equipment etc.

I can say that their is almost always a logical cause that is not a product failure. I have been the sole US tech for 20 years.

 

[rvitko]

I’ve used the same fuge bulb for 4 years. The sensor hasn’t moved and nothing has changed for 3 years. Like I said no issues whatsoever up until it going haywire this week. All I’ve ever done is clean it and put it right back in the same place on my return pump chamber. There’s no siphon as the container for the ATO is on the ground the top of the tank is much higher and the hose doesn’t even touch the water. I’m baffled as to why this is going on . I added radions about a month ago but they aren’t close to any of the Tunze parts .... it’s not like I’m a new customer I’ve had this set up flawless for 3+ years now.

At 3 years old, a failure of a sensor or pump is possible, but typically the only way the float switch can be disabled is by magnetic interference at the float or controller or a siphon. You would be welcome to send it in. I would first double check the usual causes of overfills, especially point 3, some of what you describe coincides with start up and timed fills which are not sensor depenedent.

 

[rvitko]

1) A siphon, if it is a siphon the issue will be seemingly random, it will tend to only occur when the reservoir is full and the water will fill to a level possibly above or just below the float. Siphon situation 3 is the most probable cause but note as shown in 4 that a
loop will not solve it, the end of the hose must always terminate above the reservoir water level.

2) A sensor issue. The first test is to use the self diagnostic test on the Osmolator to verify the sensor is in working order.

1) With the sensor completely wiped dry, plug in the controller. The sensor MUST be clean and dry for this test to work, a wet or dirty sensor will always fail.
2) All 4 lights will flash and it will beep, a single light will show for a couple seconds and then the normal 15-20 second pump run at startup will begin.
3) This light that is on a couple seconds is the optic sensor status, green means pass, yellow means it is marginal, red means it failed.

Assuming it passes the self test the issue is bubbles, optic sensors work by detecting the refraction of air vs water and make no differentiation between a bubble or being dry. The most overlooked source of bubbles is placing the top off hose in the vicinity of the sensors, the incoming splash will introduce bubbles and cause a fill. The hose can be routed to any area of the sump or main tank, and the optic sensor must be in a calm and bubble free area. A definitive test to verify bubbles are the cause is if you can catch it in the act of an overfill and wipe your finger across the sensor and filling stops within 5 seconds, the cause was bubbles.

3) There is a 3rd possibility but this is relatively obscure and only will apply to tanks under 50 gallons or due to a misunderstanding of how the Osmolator works. The Osmolator has timed functions in addition to sensor controlled functions and for the first 25-30 seconds it is not actually detecting water levels and is instead running a series of self diagnostic tests. The pump will always run for 15-20 seconds when you first power it up, this is so the installer can verify the pump is operational and the pump and tubing are primed and ready to fill. Also, the Osmolator always waits 5 seconds to fill to account for waves and surface movement and overfills for 5 seconds so the pump is cycled on less often. If the tank is under 50 gallons you need to open the controller and reduce the pump speed to “nano” and if it is under 30, an additional restriction such as a drip irrigation valve might be needed, this will reduce the amount of water added by these timed sequences to avoid raising the float.

 

[Caliguy1983]

Did the sensor test. First light that comes on is at the “level line” on the controller and is green. Then the pump kicks on and that light goes off. Pump light comes on yellow. There are no bubbles in this chamber. The tank is 120 gals. No siphon possible as it return into the display and isn’t touching the water. I manually pushed up the float it killed the power.

 

[rvitko]

Is the pump running though more than the approx 20 seconds it should on every start up? Point 3 explains that there are functions that are timed and not related to the sensors, it should give a green light, run the pump 15-20 seconds and then it actually starts to work, the first 25 seconds or so are preprogrammed self tests and the sensors are not actually controlling the pump.

 

[Caliguy1983]

Is the pump running though more than the approx 20 seconds it should on every start up? Point 3 explains that there are functions that are timed and not related to the sensors, it should give a green light, run the pump 15-20 seconds and then it actually starts to work, the first 25 seconds or so are preprogrammed self tests and the sensors are not actually controlling the pump.

I understand it does the 15-20 second run every time you start it up after the power is off. That wasn’t the issue and seems to be functioning normal. Right now the float is doing it’s job and not letting the pump run. Sump level is too full will take a while for it to go down. I’m worried about the sensor as it has been so sporadic. One day empty chamber the next day over full. I’ve cleaned everything and placed it all back where it should be. The only other possible thing I can think of is asterina starfish or something getting on the sensor. Not sure if that would make it function funny. If it continues to do this I’ll go to the spectrapure with the pressure shut off as I’m not going to take any chances with the $1,000s in SPS I have in the tank or the risk of my sump overflowing and making a huge mess.

 

[rvitko]

We do repair them, warranty or not, and I generally give some leeway past warranty, but even outside of that repairs are not generally expensive. I think if you examine this logically you will find a culprit, it has three safeties, and if you set everything up properly, it would never be able to add more than 1.5-3 gallons due to the time limit and you can adjust that inside the controller. My suggestion would be that you send it in, we can check everything out and at least rule out a sensor or software issue. I cannot rule out critters affecting the sensor or installation or interference from other equipment.

 

[Caliguy1983]

We do repair them, warranty or not, and I generally give some leeway past warranty, but even outside of that repairs are not generally expensive. I think if you examine this logically you will find a culprit, it has three safeties, and if you set everything up properly, it would never be able to add more than 1.5-3 gallons due to the time limit and you can adjust that inside the controller. My suggestion would be that you send it in, we can check everything out and at least rule out a sensor or software issue. I cannot rule out critters affecting the sensor or installation or interference from other equipment.

I’m going to PM you

 

[Caliguy1983]

Just an update to this. Roger had me send the unit in and he sent me out a brand new controller within a week! Excellent service from Tunze. All is working normal again. Thank you