Troubleshooting Water Well Pumps

Troubleshooting Water Well Pumps

Got water pump problems at your place? Coming up next you’ll find troubleshooting information for the main types of pump systems, alerting you to the most common sources of trouble and how to identify and fix them. You’ll find complete instructions for each of the three main types of water pumps, so some wording is repeated.

For Jet Pumps

Pump runs, but does not move water:

Air in the system – This is the usual source of trouble. If your well runs dry even for a moment, a jet pump will suck in air and stop pumping. Even when water returns to the well, a jet pump still won’t move water with air in the system. Add water to the pump casing through the top plug to displace the air. Look for air leaks if system worked fine before and water has always been plentiful in the well. Pipes, especially the typical black polyethylene pipes, can develop splits, allowing air to enter the system.

Pump won’t start:

No power to pump – Check power supply with multimeter and re-establish power if needed.
Failed pressure switch – If power is supplied to the pressure switch, but the pump doesn’t run, you could have a bad pressure switch. The contacts get worn and pitted over time. Shut the power supply OFF, double check that power really is OFF, then clean contacts or replace pressure switch. Cleaning might keep you going for a while, but replace the switch as soon as you can. They don’t cost much. All three main types of pumps use the same kind of pressure switch.
Bad capacitor – Capacitors are energy storage devices. They give electric motors a little kick start to get them rolling from a standing start. When capacitors go bad, you can often see physical signs of damage on the end of the capacitor itself. Full featured multimeters can assess the capacitance of a capacitor. More on this coming up.

For Submersible Pumps

Since submersible pumps are hidden within the well, you don’t know whether lack of flowing water has happened because the motor is bad or there’s some other problem. Here’s what to check and the order in which to check them:

Pump won’t start:

No power to pump – Check power supply with multimeter and re-establish power to pump if needed.
Failed pressure switch – If power is supplied to the pressure switch, but the pump doesn’t run, you could have a bad pressure switch. The contacts get worn and pitted over time. Shut the power supply OFF, double check that power really is OFF, then clean the contacts or replace pressure switch. Cleaning might keep you going for a while, but replace the switch as soon as you can. They don’t cost much.
Bad capacitor – Assess capacitor (see video up next), replace if necessary.
Broken or shorted power wires within the well – This problem is not uncommon with submersible pumps. Wires inside the well rub against the side of the well as the pump turns ON and OFF. This rubbing eventually wears through the insulation, allowing a short circuit that shuts down the pump. The pump is actually still good, but can’t run because of the short. Pull the pump from the well (more on this later) and fix the broken wires.
Burned out pump motor – Sometimes the motors of submersible pumps just go bad. They can last 20+ years of hard use, but much less time if a submersible pump is allowed to run dry for any length of time. Pull the pump from well and replace with a new one.
Damaged pump impeller – The impeller is a little internal propellor that moves water through the submersible pump. You can’t see it, but it’s there. Sometimes grit gets sucked up from the bottom of the well and damages the impeller. Other times running a submersible pump dry can damage the impeller. From above ground you can’t tell for sure if the problem is a bad motor or bad impeller. Either way, pull the pump from the well, find out and rectify why the impeller failed, then replace the pump.

For Piston Pumps

Pump won’t start:

No power to pump – Check power supply with multimeter and re-establish power if needed.
Failed pressure switch – If power is supplied to the pressure switch, but the pump doesn’t run, you could have a bad pressure switch. The contacts get worn and pitted over time. Shut power supply OFF, double check that power really is OFF, then clean contacts or replace the pressure switch. Cleaning might keep you going for a while, but replace the switch as soon as you can. They don’t cost much.
Bad capacitor – Capacitors are energy storage devices. They give electric motors a little kick start to get them rolling from a standing start. When capacitors go bad, you can often see physical signs of damage. See video up next for capacitor testing methods.

Motor running but pump not turning:

Drive belts too loose – Tighten drive belts. This is the usual trouble.
Seized pump – This is rare, but it can happen. Take the belts off, then try and turn the pump manually. If it can’t turn, the problem is a seized pump. You’ll need to replace your piston pump.

Pump running but not moving water:

Air in system – Piston pumps are less finicky about air, but enough of it can still shut them down. Prime system and retry. If your pump was working before, find source of air leak. It could be a split in a pipe somewhere, or it could be that your well ran dry for a time.
Failed leathers – Leathers act as valves in a piston pump. Unbolt the metal top part of the pump, replace leathers, reprime pump, then try pump again. Failed leathers are a rare thing, so ensure there’s no air in the system before you take the pump apart.

Watch the video up next to learn more about troubleshooting a submersible water well pump.

VIDEO: How to Troubleshoot a Water Pump