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.
- 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.