Use this guide to read the display symbols, error codes and alarms shown on a HYDRUS display and to decide what to do next. To fit the meter, see Installation Guide. Not sure which guide you need? Start at Meters Not Reading or Poor Signal: Where to Start.
What you need
- Your finger on the optical button on the front of the meter, to scroll through the display loops.
- To read the meter data or change the alarm settings, an optical head with a laptop or PC and the IZAR@MOBILE 2 software. Changing alarm settings also needs the expert dongle and a Bluetooth optical head.
- The platform where the meter should appear, such as the Wireless MBus receiver.
Reading the display
The meter has an optical button on the front. Press it to wake the display. The display first runs a screen check, where all symbols switch on and off, and then shows the total volume for at least 10 seconds. After that each press of the button moves to the next display loop. To save the battery, the meter goes back to sleep after 4 minutes without a button press, but it keeps recording all data.
What the display symbols mean
| Symbol | Name | What it means |
|---|---|---|
| Battery | Shows the battery status. Alarm A9 is raised when the calculated battery life is less than 400 days. The calculated battery life can be read in display loop 02. | |
| Leakage | Shows that leakage has been detected. See alarm A5 below. | |
| Calibration modification | The calibration modification symbol, as named by Diehl. Contact support if you see it on a meter that has not been reconfigured. | |
| Radio on | The radio is on. A meter does not transmit while it is in its box, and the radio starts after the meter has been filled with water. | |
| Error or alarm | An error or an alarm is active. Open display loop 05 to read the code, for example E 7 or A 5. | |
| Billing value | The value shown is the calibrated total volume, which is the value used for billing. It is the forward volume minus the reverse volume. | |
| + | Forward flow | Water is flowing in the correct direction. |
| − | Backwards flow | Water is flowing backwards through the meter. |
| 88 | Loop number | The number of the display loop that is currently shown. 88 is the display test, where all symbols are on. |
Display loops
Each loop is numbered, and the loop number is shown on the display. The loops are numbered from 01 to 09, and the meter shows the next one each time you press the button.
| Loop | What it shows |
|---|---|
| 88 | Display test, all symbols on |
| 01 | Total volume |
| 02 | Battery lifetime |
| 03 | Firmware version and checksum |
| 04 | Current flow |
| 05 | Errors and alarms |
| 07 | High resolution total volume |
| 08 | Due date and due date volume |
| 09 | Reverse volume |
| 10 | Forward volume |
Error codes and alarms
The meter detects errors and alarms, shows them on the display and sends them by radio. An error stays on the display for as long as it exists. An alarm stays on the display for 30 days after it clears, except A3, A5 and A9. The meter must detect an error or alarm for about 6 minutes on average before it is saved in the error log with its date and time. If several codes occur at once, only the one with the highest priority is shown for each position.
| Code | Meaning | What triggers it | What to check |
|---|---|---|---|
| C 1 | Electronic error | A fault in the meter electronics. | Replace the meter. If C 1 appears it is the only code shown, as it has the highest priority. |
| E 1 | Temperature error | The medium temperature is below minus 30 °C or above 100 °C, or the temperature sensor cable is disconnected or cut. | Check the water temperature and the sensor cable. If the cable is cut, the meter needs replacing. |
| E 4 | Ultrasonic hardware error | An ultrasonic transducer is defective or short circuited, or the transducer cable is disconnected or cut. | Contact support. The meter cannot measure and will probably need replacing. |
| E 5 | Communication not possible | The meter was read too often over the wired M-Bus or optical interface. | Reduce how often the meter is read. |
| E 7 | Air in the system | There is air in the measuring path, so the flow rate cannot be measured. A new meter shows E 7 and A 7 until it is full of water. | Vent the pipe and check that the meter is full. If complete venting is not possible, fit the meter at an angle of 45 degrees. |
| A 1 | Reverse flow | The consumption is below the limit of minus 8 litres (Q3 1.6 to 6.3 m³/h) or minus 80 litres (Q3 10 to 25 m³/h). It resets after 30 days without it. | Check the flow arrow on the meter and refit it the right way round. Check for a missing or leaking non return valve. |
| A 3 | No usage | The 15 minute average consumption has been below the limit of 8 litres (Q3 1.6 to 6.3 m³/h) or 80 litres (Q3 10 to 25 m³/h) for 30 days in a row. | Check whether the property is empty or a valve is closed. |
| A 4 | Ultrasonic or temperature measurement failure | Error E 4 and a temperature measurement hardware error were both active for 8 minutes in a row. It resets after 30 days. | Contact support. The meter will probably need replacing. |
| A 5 | Leakage | The 15 minute average consumption was above the limit of 0.8 litres (Q3 1.6 to 6.3 m³/h) or 8 litres (Q3 10 to 25 m³/h) for 24 hours in a row. It resets 15 minutes after the leak is cleared. | Look for a dripping tap, a running toilet or a leaking pipe after the meter. |
| A 6 | Low medium temperature | The temperature is below 3 °C on 4 measurements in a row (taken every 16 seconds) while error E 4 is active. It resets after 30 days. | Protect the pipework from frost and check the meter for frost damage. |
| A 7 | Air in the pipe | Error E 7 is active, so the flow cannot be measured. It resets after 30 days without air. | Vent the pipe. See E 7. |
| A 9 | Battery too low | The calculated battery life is less than 400 days. It clears when the calculated battery life is more than 400 days. | Plan to replace the meter. The batteries cannot be replaced. |
The meter is delivered with all alarms switched on, a leakage interval of 24 hours and an alarm hold time of 30 days. These can be changed with the IZAR@MOBILE 2 software.
Reading errors from the radio telegram
The wireless and wired M Bus telegrams carry the same status byte. The top four bits show which error or alarm is active, and the lower bits show C 1 and A 9. Errors E 1 and E 4 share a code, and so do alarms A3 and A5, so use the optical error log to tell them apart. For example, hexadecimal 30 is 0011 0000, which is error E 7.
| Error or alarm | Status byte coding |
|---|---|
| Error C 1 | xxxx 1xxx |
| Alarm A9 | xxxx x1xx |
| Error E 1 or E 4 | 0001 xxxx |
| Error E 7 | 0011 xxxx |
| Alarm A4 | 0111 xxxx |
| Alarm A5 or A3 | 1001 xxxx |
| Alarm A1 | 1011 xxxx |
| Alarm A6 | 1101 xxxx |
| Alarm A7 | 1111 xxxx |
When to call for support
Call for support if the meter is full of water, the radio symbol is shown, the details match your receiver and it still does not report. Have the serial number, the firmware version (display loop 03) and any error or alarm codes ready. Need a hand on site? Contact Product and Data Support at pds_support@sycous.com and have the details from the checklist above ready.
Frequently asked questions
Why is the display blank?
The meter goes to sleep after 4 minutes without a button press, but it is still measuring. Press the optical button to wake it.
Why does a new meter show E 7?
There is air in the measuring path, which is the factory state until the meter has been filled with water. Vent the pipe, and if complete venting is not possible fit the meter at an angle of 45 degrees.
Does reverse flow reduce the billing reading?
Yes. The calibrated total volume, shown with the lock symbol, is the forward volume minus the reverse volume. The meter has a built in hysteresis so that a swinging water column is not counted as consumption.
How long does an alarm stay on the display?
30 days after it clears, except A3, A5 and A9. Every alarm is kept in the error log with its date and time.