Careful! Dry-running will damage the bearings!
- Flush pipework thoroughly with water and vent it.
Beforehand:
- Disconnect the pump from the power supply and secure against reconnection.
- Check that no voltage is present.
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.

To vent, first close the isolation valves.

Unscrew bleeder screw completely …

… and fix a usual drain valve with ¼“-thread connection.

Open isolation valve in front of pump inlet and vent pump by opening the drain valve. Make sure, that return line gets completely vented.

Close isolation valve in front of pump inlet, unscrew drain valve, …

… and remount bleeder screw to pump housing.

Slowly open the isolation valves again.