Tunze Osmolator 3155 Pump Not staying on

[SaltieG]

For whatever reason, the pump for my 3155 ATO will only run for about 20 seconds and then it stops pumping. The unit is a couple years old and the controller shows that the pump should be on so I know its not the contoller. I even tried switching the wires around and each time I take the wires apart and then reconnect them, it comes back on for another 10-20 seconds but once again stops and won't restart.

 

[rvitko]

The pump is dying, the power it consumes exceeds the safety limiter in the controller. In general the pumps are expected to last 2-3 years, they cost $24 approx to replace and are readily available, part 5000.020.

 

[SaltieG]

Alright I had a feeling it was on it's way out. I just bought it used off a forum member and I know he had it a few years so I'm not the happiest guy on the earth right now being sold something that's not working properly.

 

[rvitko]

Well, hold on, this raises another possibility. Do you have an exact idea of the age of the unit? Any chance of a photo of the power supply and the circuit board inside the controller? If the controller was made before 2008, it will have a lower power limit for the pump and these units only work with a 9V power supply (they came with either 9V or 9/12V with a switch when new).

 

[SaltieG]

I could get a picture and check the power supply for the voltage. When I first hooked up the entire unit I had the sensor about an inch above the water level and I powered on the unit thinking it would just fill my sump until it leveled off but that's when I realized it was only staying on for 30 seconds. At that point I moved the sensor lower thinking I just had too much space between it and the water level and maybe the pump was only allowed to stay on a certain time before it shut down. At the time the controller was just flashing "too low" so that's why I moved the sensor thinking the level was too low for the unit to fill the sump the rest of the way, If that makes any sense. I just figured maybe the pump was only designed to run a certain length of time and then shut off but that really makes no sense so that's when I started thinking maybe it's a bad pump.

 

[rvitko]

Too low does come on after the controller tries to run the pump and top off for 10 minutes. This generally is designed to shut it down in case the sensors have both failed or the tank is leaking so no amount of water is going to raise the level. This is clearly that the controller is shutting off power to the pump because either the pump draws too much power due to being faulty or possibly a corroded connection, or the controller is an older version and can only run the pump when the original 9V power supply is used, the power supply we use now is 11V.

 

[SaltieG]

The weird thing is that the controller still lights up "pump on" even when the pump shuts off so I believe it is supplying power to the pump but it's the pump that stops on it's own. Il even try to put a 9v battery to it and see how long the pump stays on to rule out the controller.

 

[rvitko]

A picture of the controller board would be the best way to narrow it down. The 9V battery test is of limited value, it only gives us an answer if the pump doesn't work at all.