Flushing and vent

CAUTION! Dry-running will damage the bearings!

  • Flush the pipework thoroughly with water and vent it.


DANGER! Pressurised system!

  • Before working on the motor or pump connections, close the shut-off valves.


WARNING! Risk of scalding due to hot water!

  • Avoid direct contact with escaping hot water.
  • The pump housing can similarly reach a high temperature due to the hot medium being pumped.


  1. If no venting valve (fill & drain valve) is present, the system must be vented through the pump housing.
  • To vent, first close the shut-off valves.

  • Unscrew the motor from the pump housing …

  • … and screw the venting flange (VORTEX EF 150) onto the motor (max. 20 Nm).

  • Open the shut-off valve upstream of the pump again and allow water to escape through the venting flange until the pipework is free of air.

  • Close the shut-off valve upstream of the pump …

  • … unscrew the venting flange from the pump …

  • … and reattach the motor to the pump housing.

  • Retighten the union nut (max. 20 Nm).

  • Slowly open the shut-off valves again.