How to Fix a Continuously Running Self-Priming Pump?

[StLeila]

It is likely that there is air leakage in the water valve of the pressure well. The best solution is to install a separate pipe for the self-priming pump into the well. If this is not feasible, install a valve at the bottom of the pressure water device and close it when the device is not in use. This prevents air from entering the pipeline, allowing the self-priming pump to function properly. Solutions for self-priming pump motor malfunctions: 1. Pump does not work after power is connected: This could be due to issues with the power plug or wiring, such as insufficient power or a short circuit. 2. Difficult to start or noise during startup: During inspection, gently move the fan blade with a small bamboo stick. If the motor runs normally, the starting winding may be damaged. Replace the capacitor with one of the same capacity or repair the starting winding. If the motor is stuck, it may be due to faults in the motor or pump head, such as bearing damage or impeller blockage. 3. Motor runs but at a slow speed, with overheating and a burning smell: This could be caused by a motor short circuit. Open the motor to assess the damage and repair accordingly. 4. Excessive noise and vibration during operation: This is often due to bearing damage or improper fit between the bearing and the motor casing. Disassemble the motor for inspection. If the bearing is damaged, replace it. If the bearing "runs outer circle," notch the pump casing's fitting surface. If the bearing "runs inner circle," notch the worn part of the motor shaft. For severe wear, use welding followed by turning to repair.

[DiJack]

Last time my self-priming pump kept buzzing while drawing water, and after much effort, I finally realized the cause wasn’t complicated. First, check if the pump is drawing water properly when powered on. If the water flow from the hose is intermittent like an old man coughing, chances are the filter screen is clogged with river mud. Once, when I opened the bottom cover of the pump, I found rotten leaves as big as a palm stuck to the filter screen. If the pump suddenly starts running dry and overheating, focus on checking the pipe joints—that time at my place, a plastic joint had cracked a tiny gap, letting air sneak in and preventing the pump from fully priming. If all else fails, just touch the pump casing—if it’s hot enough to fry an egg, cut the power immediately; that’s usually a sign the mechanical seal is shot.

[DelBradley]

I'm quite familiar with repairing self-priming pumps. I've basically handled pump failures for over twenty households in the village. The most common reason for non-stop operation is a stuck check valve. Just open the pump housing and wiggle that small metal flap with your hand. If it's jammed by sand, poke it with a screwdriver. I remember when my cousin built his new house, the pump ran all night—turned out the valve was installed backwards, causing backflow that disabled the pressure switch. Another hidden culprit is impeller wear. One household's pump had been running for seven years, and when opened, the impeller was worn down to a thin slice—no wonder it couldn't pump efficiently enough to shut off. Most importantly, after every repair, always apply a layer of dish soap on the rubber seal before tightening it back, otherwise leaks will cause even bigger trouble.

[LaVanessa]

Don't panic if your self-priming pump keeps running non-stop. Follow this troubleshooting guide: Wear gloves and feel the temperature difference between inlet and outlet pipes—if it exceeds 10°C, it indicates dry running. Then, turn off the power and listen for the check valve's clicking rebound sound. Finally, check if the pressure gauge is stuck at a certain reading. Last week, I helped a neighbor fix their pump and discovered a bizarre situation—a seemingly intact pipe actually had a pinhole-sized air leak at a buried elbow joint, only audible as a hissing sound during quiet nights. In fact, 80% of faults can be resolved by simply replacing that $15 rubber diaphragm, so don't let repair shops trick you into buying a whole new unit.