Grundfos TPE2 - The Pump Runs but Delivers no Water; The Pump Runs Backwards When Switched off; Leakage in Shaft Seal; Noise

Cause Remedy
The pump draws in air. 1. Increase the liquid level on the inlet side.
2. Keep the liquid level as constant as possible.
3. Increase the inlet pressure.
29.6 The pump runs but delivers no water
Cause Remedy
The inlet pipe or pump is blocked by impurities. Clean the inlet pipe or pump.
The foot or non-return valve is blocked in closed
position.
Repair the foot or non-return value.
There is a leakage in the inlet pipe. Check the gaskets and bolts torque.
Replace gaskets, if defective.
There is air in the inlet pipe or pump. Vent the inlet pipe or the pump.
29.7 The pump runs backwards when switched off
In twin-head pump installations, the backup pump often rotates slowly.
Cause Remedy
There is a leakage in the inlet pipe. Check the gaskets and bolts torque.
Replace gaskets, if defective.
The foot or non-return valve is defective. Replace the foot or non-return valve, if defective.
The foot or non-return valve is blocked in open or
partly open position.
Repair the foot or non-return value.
29.8 Leakage in shaft seal
Cause Remedy
The shaft seal is defective. Replace the shaft seal.
29.9 Noise
Cause Remedy
The pump is cavitating. Increase inlet pressure.
The pump does not rotate freely (frictional resistance)
because of incorrect pump shaft position.
Check the motor bearing, wear ring and impeller, shaft
seal
Replace them, if worn out or blocked.
There is resonance in the installation. Fasten the support on foundation.
Add damping joints.
Make sure the pipes are properly supported.
There are foreign bodies in the pump. Clean the pump.
95
English (GB)