Possible Pump Malfunctions And Their Elimination Methods

Jan 10, 2026

Possible pump malfunctions and their elimination methods:

 

1, The pump does not absorb water, and the pointers of the pressure gauge and vacuum gauge jump violently.
Method: Inject water into the pump and tighten to block the exposed area.
2, The pump does not suck water, and the vacuum gauge shows high vacuum.
Method: Correct or replace the bottom valve, clean or replace the suction pipe, and reduce the suction height.
3, The pump is not producing water, but the pressure gauge shows pressure.
Method: Check or shorten the water outlet pipeline, correct the rotation direction of the motor, clean the impeller, check the power supply voltage, and increase the speed.
4, Insufficient flow or low head of single-stage double suction pump.
Method: Clean the impeller or pipeline, replace the damaged sealing ring, and adjust the rated speed.

 

5, The pump consumes too much power, loosen the packing gland.
Method: Check the cause, eliminate mechanical friction, and reduce the opening of the gate valve.
6, The sound inside the single-stage double suction pump is abnormal, and the pump cannot fill water.
Method: Clean the bottom valve of the suction pipeline, lower the suction height, check the bottom valve, lower the suction height, block the leak, lower the liquid temperature, adjust the outlet valve to operate within the specified performance range.
7, The pump is vibrating abnormally.
Method: Adjust the outlet valve to operate within the specified performance range, calibrate the concentricity of the pump shaft and motor, and tighten the foot bolts.
8, The bearings of the single-stage double suction pump are overheated,
Method: Check and clean the bearing body, add lubricating oil, and calibrate the concentricity of the two shafts on the same centerline.

Notes:

1. First, check if the bolts are loose, if the power cord and plug are intact, and if the motor insulation resistance is greater than 2 megohms.
2. To prevent electric shock accidents, corresponding security measures such as leakage circuit breakers or electric shock safety devices must be installed, and reliable grounding must be carried out.
The operating voltage range of the pump must be between+5% and -12% of the rated voltage, otherwise it will shorten the service life of the motor or burn it out. If the electric pump is used at a distance from the power source, the power transmission line should be appropriately thickened, otherwise the voltage will drop and it will not be able to operate.

 

3. Close the power switch and let the pump idle for about 2 minutes, then check if it starts, runs normally, and turns correctly.
4. Fix the pump body, use steel or rubber pipes (not too soft to avoid flattening), connect the inlet and bottom valve, and place the bottom valve perpendicular to the horizontal plane, at least 30cm away from the bottom of the water, to avoid sucking up sediment.
5. Before using the centrifugal pump for clean water and the automatic suction pump for clean water, the storage tank should be filled with water. If it cannot automatically discharge water after being powered on for several seconds, there is no need to fill it with water for future use.
6. Before using the self-priming water pump and automatic self-priming water pump, the water storage tank should be filled with water. If the water cannot be automatically discharged after being powered on for several seconds, there is no need to fill it with water for future use.
7. When in use, the motor should be kept dry, and attention should be paid to the condition of water level drop. The bottom valve should not be exposed outside the water surface. When the temperature is below 4 ℃. Anti freezing measures should be taken to prevent the pump body from freezing and cracking.
8. If not in use for a period of time, the accumulated water in the pump should be drained (the self-priming pump and automatic pump should pour out the water stored in the storage tank), the main components should be cleaned, coated with anti rust oil, and placed in a ventilated and dry place for later use.