Wilo 4047573 Instructions D’installation Et De Fonctionnement page 38

8.1 Filling and venting
Fill and vent the system correctly.
The pump rotor room is vented automatically after a short
operating period. Dry running for short periods will not harm the
pump.
Please proceed as follows if it is necessary to vent the rotor
room:
• Switch off the pump.
WARNING! Risk of injury!
Depending on the pump or system operating conditions
(fluid temperature), the entire pump can become very hot.
Touching the pump can cause burns!
• Close the shut-off device on the pressure side piping
WARNING! Risk of injury!
Depending on the temperature of the fluid and system pres-
sure, when the venting screw is opened, hot liquid or gaseous
fluid may escape or shoot out at high pressure.
Escaping fluid can cause scalding!
• Undo the venting screw carefully with a suitable screwdriver
and unscrew it completely (fig. 9).
• Carefully push back the pump shaft with a screwdriver several
times.
• Protect electrical parts from any escaping water.
• Switch on the pump.
Note: The pump may jam if the vent screw is undone, depend-
ing on the operating pressure level
• Screw the venting screw back in again after 15 to 30 seconds.
• Open the shut-off device again.
Installation and operating instructions Wilo-Star-Z/-ZD
English
31