Here are a choice of frequently asked questions.

Problem or error


The device shows a constant fill level at 100%.

The red and white sensor cables have been wrongly connected (switched). Connect the white wire of the cable to the left of the measurement pick-up and the red wire to the right.

The red error display flashes.

This occurs when the tank fill level is too low. The user is made aware that the system now takes water from the mains supply. This is not error warning! So as to avoid confusion, the newer devices show  this warning sign:   Warning sign

The display shows a continuous ”Sensor error”
(in some cases ”701” for the fill level indicator).

The white sensor cable insulation is not longer intact. Remove the sensor cables and weight from the water. The error warning should now stop (the shown fill level is then 0%). For equipment with a mains water back-up, the device can continue to run in emergency mode. If this error is displayed, then please call the service hotline under +49  3984- 80 87 17 or sent us an E- Mail. (We prefer to receive an E-Mail!)

The error code ”602” appears in the display.

The calibration value has not been acknowledged by the device. This particular error can only appear when, after the display ”902” has lit, too much time has elapsed before the re-pressing of the calibration button. If this happens then simply repeat the calibration process.

Can I calibrate the fill level indicator without the tank being completely filled?

Yes! For a provisional calibration, proceed as follows:
Follow the instructions in the user information  for cutting the sensor wires to length and make the connection as descirbed but do not place the measurement sensor pick-up  into the tank. Fill now a plastic bucket with approximately
10 L of mains water and place the stainless steel weight with the two sensor wires (red and white) so they are completely covered by water, but  pay special attention that the measurement sensor pick-up remains dry!
Now the calibration process can be performed following the user information without first filling the tank.
Please remember however that this methode of calibration is only a functional check and does not replace the full calibration process with a full tank! This method is only makeshift and has inherent problems. As soon as the tank is filled, then the calibration process should be performed again fully.

What happens if the insulation of the white wire is damaged?

Depending on the device, the displayed error message will read either Sensor defect¯ or ”701” .
For a temporary solution to enable work to continue, the sensor must be removed from the water. The fill level of 0% will  now appear in the display. The device is now working in back-up mode and uses water from the mains supply.

What happens if the insulation of the red wire is damaged?

The red cable is conducting current by way of the stainless steel weight to the rainwater in the tank and there appears to be no impairment to the device functions. However, the wire will begin to
corrod at the point of damage after a short time. We would therefore advise an exchange of the sensor wire.

Is it approved to run the wires of the sensor through an additional protective tube?

No. The red and the white sensor wires must be allowed to hang freely in the tank.

What can happen if my tank is not made of a synthetic material but for example from metal or ferro cement?

The measured value will be distorted. In a bad case, this may be up to 10% or even more!
If the tank is therefore not made of a synthetic material it is of great importance to ensure that the wires are positioned down the centre of the tank. Pay special attention that the greatest possible distance between the wires and any metallic parts is kept. This also applies to the walls of the tank as there may also be steel reinforcement in a concrete tank.
These devices have been conceived and constructed primarily for use in synthetic tanks.

What happens if the measurement sensor pick-up becomes

The measurement sensor pick-up must be mounted at least 10cm to 15cm above the overflow outlet to ensure there is  no possibility of  the measurement sensor pick-up being submerged. If however the measurement sensor pick-up  for any reason does become submerged, then replacement or repair  is not covered by the terms of the guarantee.

Is it possible to replace the data cable with an other cable?

Yes, it is possible to use any cable suitable for the installation under ground.

What is the maximum data cable length?

A dependable data transfer is possible up to a distance of 50m.

Why, when the tank is full is there no acoustic alarm triggered from the overflow sensor although the red warning LED is flashing?

The digital overflow sensor has not been re-set after it has been triggered. The ”Alarm off”¯ button has been pressed only one time to deactivate the acoustic signal. After the tank has been emptied, it has been forgotten to press the ”Alarm off”¯ button a second time. This user error is often first noticed when the tank is once again full or overflows. Convince yourself! That after each emptying of the tank the device is re-set by pressing the ”Alarm off” button. The red LED is now not flashing!