4” SUBMERSIBLE WELL PUMP TROUBLESHOOTING
 

4” Submersible Troubleshooting

 

 

 

4” Submersible Well Pump Troubleshooting

Use caution when checking anything electrical.  Pumps use 230 or 115 volts AC which can injure or kill. Always shut off all power to the pump before servicing or inspecting it (except as specified).  Some testing of live electrical power may be required. Hire a professional electrician if you are not comfortable with this.

Symptom
Pump won’t start or run

Possible Cause


Voltage being fed to the pump does not match its rated voltage

Corrective Actions To Check/Try


Confirm that the voltage you have connected to the motor is what the motor is rated for

 

Fuse or circuit breaker in your fuse/circuit breaker box has tripped or blown

Inspect wiring, pressure switch, etc. for a problem that caused fuse/breaker to blow and repair as needed. After that is fixed, reset breaker or replace fuse.

 
Voltage at pump motor is too low

Measure voltage at motor when it is trying to run. Compare to base voltage that is being fed to it. If running voltage is 5% or more below the base voltage check wiring for poor connections or wiring that is too light in gauge for the pump’s horsepower and wire length.

 
Power wires are loose / disconnected

Check power at pressure switch, and then at motor, to determine which wire(s) need to be repaired.

 
Starting component of motor has failed

In a 3-wire pump system, there will be a control box above ground which contains a capacitor, etc. Test components and replace as needed. In a 2-wire pump system, the starting components are in the motor and cannot be repaired. Replace pump.

 
Pressure switch not wired properly or has failed

Check voltage at pressure switch. Check if voltage on pump side of switch matches voltage on supply side. Replace switch if needed.

 
Motor has failed

If everything else checks out OK, the motor has failed. Replace motor if available separately, entire pump if not.

 
 
 
 
 
 

Motor hums but little or no water is moved

Motor is just humming – not running
Follow diagnostics above for “Pump won’t start or run”
 
Pump motor is running on wrong voltage

Make sure you have connected the voltage that the motor is built to accept

 

Depth-to-water in your well is outside the appropriate range for the pump you’ve installed

Every pump has a certain range of depth-to-water where it will work. If depth-to-water is too shallow, the pump may be cavitating or won’t prime. If too deep, it simply might not be able to get the water to the surface. Replace pump with one that is appropriate for your well.

 
Check valve is stuck closed or is installed upside-down
Confirm correct orientation of check valve. Replace check valve if necessary.
 
Drop pipe down to pump is split or otherwise leaking
Inspect drop pipe for leaks or joints that hve come loose. Repair / replace as needed.
 
Connector shaft between motor and liquid end is sheared or stripped
Replace connector shaft (if available) or entire pump unit.
 
Pump internals are worn or damaged

If pump is older, or has been pumping sand, etc. it simply may be worn out. Replace pump

Pump runs for a short time and delivers some water, but shuts off by itself

Voltage is too low, causing motor to shut off due to thermal overload

Check voltage at pump while it’s running. Compare to base voltage that is being fed to it.   If running voltage is more than 5% below base voltage, inspect wiring for loose connections and/or insufficient wire guage.

 
Circuit breaker has tripped or fuse has blown

Power wires are touching or grounded where they connect, touching steel well case, or touching steel drop pipe. Correct wiring.

 

Pump is free-flowing. Pump will draw higher amps if allowed to free-flow with little restriction against it. Need to restrict the output to keep the pump within its designed range.

 
Wrong size fuse or breaker supplying circuit. Check manual for proper size.
 

If 3-wire system, make sure control box is properly matched to pump motor.

 
If all other items test OK, pump may be blocked with debris.
 

Pump is being used in a cistern, lake, or other body of water and is overheating, tripping thermal overload.

When used in a larger body of water (not a 6” cased well) it is necessary to sleeve the pump. Call Customer Support for more information.

 

Pump moves water but not to its full capacity

Depth-to-water in well is not what originally thought

If depth-to-water (from top of well down to water’s surface) is too shallow for the specific model, it can cavitates. If depth-to-water is too deep, the pump’s performance will not be what it would at shallower depth.

 

230 volt motor has 115 volts connected to it causing it to run at half speed.

Check the rated voltage of the pump. Be sure you have connected proper voltage from circuit breaker box.

 
Drop pipe down to pump is cracked, split, or otherwise leaking

Leaking drop pipe will allow water to leave the pipe and go right back into the well. Repair or replace pipe.

 
Drop pipe to the pump is smaller (in diameter) than it should be

Always use a drop pipe that is equal to, or larger than, the discharge size of the pump. Replace as needed.

 

Drop pipe is partially blocked with corrosion, scale, mineral deposits, etc.

Any deposits in pipe will limit flow rate. Replace drop pipe
Pump starts too frequently

Pump turns on and off at proper settings of the pressure switch and pressure holds steady when water is not being used.

Nothing wrong with pump. See tank troubleshooting section as the problem is likely tank-related.

 
Pressure in the system drops by itself though nobody is using water.

Check valve has failed allowing water to leave the system and go back into well. Replace check valve.

 

Underground piping is leaking allowing water to leave the system. Repair piping.

Pressure switch “chatters” at beginning of pump cycle

Pump is not receiving proper voltage

Check voltage at pump while it’s running. Compare to base voltage that is being fed to it.   If running voltage is more than 5% below base voltage, inspect wiring for loose connections and/or insufficient wire guage.

 

Restrictions in piping between pressure switch and tank causing switch to get inaccurate reading

Too much length of pipe, too many elbows, pipe partially plugged with rust or scale, or other obstruction in piping is causing pressure at switch to be higher than in the tank. Switch should be within 10 pipe feet of tank. Try replacing 90 degree elbows with 45’s or flexible pipe.

 
 
 
 

Pressure switch chatters, or pump cycles at the end of the pump cycle (after system has come to, or close to, shut-off pressure)

Check valve installed in piping between pressure switch and tank

Relocate pressure switch or check valve. Check valve must be between pressure switch and well. Must NOT be between pressure switch and tank.

 

Restriction in piping between pressure switch and tank causing switch to get inaccurate pressure reading

Too much length of pipe, too many elbows, pipe partially plugged with rust or scale, or other obstruction in piping is causing pressure at switch to be higher than in the tank. Switch should be within 10 pipe feet of tank. Try replacing 90 degree elbows with 45’s or flexible pipe.

 
Debris in pressure switch fitting

Remove pressure switch and check its inlet fitting for rust, scale, dirt, etc. Clean as needed.

Pump won’t shut off and system shut-off pressure is NOT being reached

Pump is operating on wrong voltage
Confirm that correct voltage is connected to pump. (example: 230 volt pump receiving 115 volts will operate at half speed)
 
Pump is not moving water as it should

See corrective actions above in section labeled “Pump moves water but not to its capacity”

 
Pump is worn and needs to be replaced

If all else checks out OK, the pump is simply worn out and needs to be replaced.   To ensure good pump life, ensure that the proper horsepower is chosen for the depth-to-water in your well, and that pump is not set too low and is able to pick up sediment off the bottom of the well

 
 
 

Pump won’t shut off even though system shut-off pressure IS being reached

Pressure Switch is wired incorrectly

Check owners’ manual for proper connection of pump and power wires. Correct as needed.

 
Debris in pressure switch inlet

Remove pressure switch and check its inlet for rust, dirt, or other debris. Clean as needed.

 
Pressure switch is out of adjustment or defective
If other items check OK, switch is bad. Replace switch
Air is getting into water system. (air spits from faucets, shower, etc.)

Recently replaced a standard air-over-water tank with a pre-charged bladder tank. Bleeder orifices still in drop pipe.

Drop pipe down to pump still has bleeder orifices that are needed when using a standard air-over-water tank. Orifices need to be plugged.

 
Pump is drawing well level down low enough that it can suck in air
Options:

If possible, set the pump lower (not so deep that it picks up debris off the bottom)

Install an inline “Dole Valve” that will limit the GPM flow rate of the pump

Replace pump with one that has a lower GPM flow rate

Have well drilled deeper so it will hold more water. Then set pump deeper.

 
Drop pipe down to pump is cracked, split, or otherwise leaking

Leaking drop pipe will allow water to leak out of drop pipe between pump cycles and allows air into it. Next time pump runs that air is pushed up into tank. Repair or replace drop pipe.

Pressure at faucets, etc. drops to nothing before pump starts again

Air charge in the pre-charged bladder tank is incorrect

Air pre-charge in the tank is probably too high. Adjust tank pre-charge (according to tank manufacturer’s directions) to 2 psi less than the cut-in (turn on) pressure of your pressure switch.