Error codes and LED signals

LED signals

Find the complete mapping of all colours and lighting patterns in the LED colour legend.

Red pulsing, entire ring: An error has occurred. Check the details in the app.
Red pulsing, top: The dirt filter is clogged. Clean it and reset the message in the app.
White pulsing: Recovery mode; the Wi-Fi credentials have been deleted.

Error messages in the app

Message	Meaning	Next step
Device unreachable	No connection between cloud and device	Check power supply and Wi-Fi
Sensor error	No valid sensor data	Check the sensor and data cable
Filter maintenance required	Filter must be cleaned	Clean the filter and reset the reminder
Firmware update failed	Update was not transferred completely	Try again with a stable Wi-Fi connection

Active WaterGuard Refill errors

The product-wide error list is filtered here for WaterGuard Refill; not all global codes apply to Refill.

Note about the error list

The error codes are organised by observable problems. When an error occurs, start with the relevant troubleshooting article and use the error code for classification.

Code	Meaning	Next step
100	Maximum refill duration exceeded	See the explanation and diagnosis under Refill problems. Confirm or reset the error in the dashboard after resolving it.
202	Tank not defined	Define the tank in the app or web dashboard. Without a tank, no correct percentage level or volume-based tank content can be calculated.
0	System ready for operation	Not an error. The system is operating correctly and there are no active errors.

Reserved sensor errors – automatic detection being prepared

The following codes are intended for a future diagnostic function but are not yet automatically evaluated in the current WaterGuard Refill functionality. They are therefore not detected reliably.

Automatic detection being prepared

This error code is already intended for a future diagnostic function but is not yet automatically evaluated in the current WaterGuard Refill functionality.

Code	Meaning	Status
218	Level measurement unstable – readings fluctuate outside the permitted range.	In preparation
301	No connection to the sensor unit.	In preparation
303	No sensor connected.	In preparation
309	Sensor cable not connected.	In preparation

Technical system errors

Do not attempt dangerous self-repair for the following technical errors:

Code	Meaning	Next step
302	Temperature sensor error	Contact myCistern support.
310	Fuse blown	Contact myCistern support. Do not repair the circuit board.

Different technical causes are possible, such as no download, a storage problem, a damaged file, a connection interruption, or a certificate or server error. Safe, realistic steps for end users are limited to:

Check the WaterGuard internet connection.
Try again later if the interface allows it.
If it happens repeatedly, contact myCistern support.

Internal system errors

Errors in the internal file system or configuration files are not suitable for self-service repair. If such an error occurs in the WaterGuard context, contact myCistern support. No instructions for accessing internal file systems are provided.

Error codes that do not apply to WaterGuard Refill

The following codes concern other functional areas or are not relevant to the current WaterGuard Refill:

101 – Maximum emptying duration exceeded (emptying function)
110 / 111 – Leak protection valve (not implemented for the current WaterGuard Refill)
210 / 211 – Irrigation schedule/system (different functional area)
240 – Maximum refill quantity exceeded (not implemented for the current WaterGuard Refill)
241 – Leak detected (not implemented for the current WaterGuard Refill)

Weather data or inflow forecast is missing

Weather-related codes, such as location detection, undefined collection area, and weather forecast or history, concern weather and forecasting functions and are not the focus of Refill troubleshooting.