The LORENTZ S1-700 system uses centrifugal pumps. Unlike positive displacement pumps, centrifugal pumps require a minimum motor speed and available power to overcome the total dynamic head (TDH) of the installation before they can start delivering water.

In some situations, the pump may be running, but no water is delivered. In this case, the S-Connect app displays a flow rate of "0 m³/h", even though the motor speed is greater than zero.

Centrifugal pumps can only deliver water when the available power is sufficient to reach the required discharge head.

If the motor speed or available power is too low to overcome the total dynamic head (TDH), the pump will rotate but no water will flow. This is normal behavior for centrifugal pumps and does not generate a fault or error message in the S-Connect app.

The S-Connect app may display the following message:

“Centrifugal pumps require a minimum power in order to deliver water at a certain discharge head. If the app displays a flow rate of 0 m³/h or no water comes out, either the power is not sufficient or you have entered an incorrect value for the total dynamic head (TDH).”

• The pump appears to be running.
• Motor speed is greater than 0.
• Flow rate shown in the app is 0 m³/h.
• No water is delivered at the outlet.
• No fault or error message is displayed.