JET PUMP TROUBLESHOOTING
 

Jet Pump Troubleshooting

 

Jet Pump Troubleshooting

Please use caution when checking anything electrical.  Pumps use 115 or 230 volts AC which can injure or kill.
Always turn off circuit breaker (or remove fuse) that feeds the pump before servicing or inspecting it.  Some of these troubleshooting items will involve voltage testing.  If you are not comfortable doing that, hire a professional electrician.

Symptom
Possible Cause
Corrective Actions To Check/Try
Pump won't start or run

System pressure has not dropped to switch's "On" or "Cut-in" pressure

Run more water out of the system until pressure drops to the "On" point of the pressure switch

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

Inspect wiring, pressure switch, and motor for a problem that would have tripped the breaker or popped the fuse.  Repair problem then replace fuse or reset breaker

Motor is set to incorrect voltage, or, voltage being fed to motor does not match the motor's rated voltage.

Many pumps have dual voltage motors.  Consult owners' manual to find how to set the pump to the correct voltage according to what the voltage is that it will actually be connected to.

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

Hose from pump body to pressure switch is blocked / clogged / frozen or has come off one end.

Relieve pressure from system.  Remove hose from pump body and pressure switch and see if you can blow through it.  If clogged, remove whatever is clogging it.  Reinstall hose

Pressure switch contacts are dirty or burned

Measure voltage on motor side of the switch to see if proper voltage is getting through.  If not, replace pressure switch

Power wires are loose / disconnected

Check voltage at pressure switch to determine which wire(s) are loose and repair as needed.

Starting component of motor has failed

Test motor's capacitor and start contactor to see if they are good.  Replace as needed if not.

Motor has failed

If everything above tests OK, the motor may have failed.  You will need to replace the motor or pump unit.

Motor runs but no water is delivered at all

Pump has not been primed

Follow the directions in your owners' manual regarding priming the pump

Pump is sucking air

Your suction pipe may have small leaks at joints, etc. where air can be pulled in.  Entire length of suction pipe and all fittings must be completely air tight.  (One test method is to use plastic cling wrap and wrap every joint to temporarily seal air leaks.)

Depth-to-water in well is too deep for the particular model of pump you have

Depth-to-water is depth from where pump is down to surface of water. For shallow well jet pumps this distance cannot exceed 25'.  For convertible deep well jet pumps, consult the manual for proper setup and limitations.

Check valve is installed upside-down or is stuck closed

Check valve must be installed in direction of water flow according to the arrow on the valve.  Ensure the valve is able to open and allow flow.

Pump motor is running on wrong voltage

For dual-voltage motors, confirm that motor is set to same voltage that you have it connected to.

For single voltage motors, make sure you have connected the voltage the motor is built to accept.

Too much restriction in suction pipe

Using a suction pipe that is too narrow, too long, or has too many elbows in it can cause too much restriction for the pump to be able to pull through. Never use pipe that is narrower than the suction port.  Limit the number of elbows.  Keep the suction pipe as short as possible.  If you do have a long suction pipe, increase pipe size from that of the suction port size.

Check valve, tee, or elbow installed too close to inlet of pump

We recommend a straight section of pipe at the pump's suction port (between pump and first elbow, tee, or check valve) that is a minimum of ten times the pipe diameter.  Use 24" to be safe. Having an elbow, tee, check valve, or other disruption too close to the inlet of the pump can cause cavitation inside the pump.

Suction pipe is not far enough down into the water

Ensure that end of suction pipe is into the water far enough

End of suction pipe is down too far into source of water and is buried in mud or dirt

Make sure suction pipe is not too close to bottom of well, lake, etc. so that it cannot pick up mud, etc.

Suction pipe is frozen

Make sure suction pipe is not frozen due to exposure to cold.  Thaw pipes for the pump to work now.  Bury the pipes below frost line for permanent solution.

Pump runs for a short time, delivers water, but shuts off before system pressure is reached

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

Check voltage at pump while its running.  Compare to the base voltage it is being fed.  If voltage the pump is receiving is more than 5% below the base voltage inspect your wiring for loose connections or insufficient wire size (gauge).

Pressure switch is out of adjustment

Adjust pressure switch properly or replace switch

Circuit breaker (or fuse) powering the pump has popped off or blown out

Inspect pump for jammed impeller or other damage

Ensure that wire from breaker (fuse) box to pump is heavy enough gauge.  Replace as needed.

Pump is free-flowing.  Motor will draw more amps when pump is allowed to flow lots of water with no back-pressure.  Need to restrict the output to keep the pump within its designed performance range.

Pump moves water but won't shut off

Power supply wires connected to wrong screws in pressure switch

Power supply wires need to be connected to the two connection screws that do not already have the motor wires connected to them.  If the power wires are on the same screws as the motor wires, the switch cannot shut off power to the pump

Pump is not building to the shut-off pressure of the pressure switch

See next troubleshooting item below: "Pump won't build to shut-off pressure"

Pressure switch is out of adjustment, points are welded closed, or it's defective

Adjust pressure switch properly or replace switch

Water level in well is dropping below pickup pipe or below pump's lift capability

Make sure bottom of suction pipe is below maximum depth that pump is capable of and/or deepest level that water is dropping to during operation..  Check production of well and make sure surface of water in well is not dropping below pump's capability when pump is removing water from well.  If water level is dropping too low it may be necessary to switch to a deep well pump.

Water is being used somewhere in system at a rate equal or greater than what the pump can provide

Shut off faucets, etc.  If using pump on a sprinkler system and the sprinklers are operating properly, there is no problem. It is better for the pump to run continuously rather than cycle on and off.

Pump won't build to shut-off pressure

Pump is sucking air

Your suction pipe may have small leaks at joints, etc. where air can be pulled in.  Entire length of suction pipe and all fittings must be completely air tight.  (One test method is to use plastic cling wrap and wrap every joint to temporarily seal air leaks. If pump is then able to come to pressure, you have covered the leak and now must find which joint it is.)

Water level in well drops too low

Make sure bottom of suction pipe is below maximum depth that pump is capable of and/or deepest level that water is dropping to during operation..  Check production of well and make sure surface of water in well is not dropping below pump's capability when pump is removing water from well.  If water level is dropping too low it may be necessary to switch to a deep well pump.

Debris partly blocking pumps' nozzle & venturi or impeller

Inspect & clean nozzle, venturi, and impeller

Wrong nozzle/venturi in use (for convertible deep well jst pumps only)

Check owners' manual for pump to determine proper ejector package to use.  Check ejector package instructions to determine which nozzle and venturi to install in the package for your particular model of pump.

Motor is operating on wrong voltage

If motor is set to run on 230v but is only being fed 115v it will run at half speed and cannot build proper pressure.  Check motor label for proper voltage.  If dual-voltage motor, set voltage selector to match voltage that is actually connected to the motor.

Impeller and/or diffuser is worn

If all items above check as OK, overhaul pump:  Replace impeller, diffuser, and necessary seals & gaskets

 

Pump moves water but not to its capacity

Pump is sucking air

Your suction pipe may have small leaks at joints, etc. where air can be pulled in.  Entire length of suction pipe and all fittings must be completely air tight.  (One test method is to use plastic cling wrap and wrap every joint to temporarily seal air leaks.)

Depth-to-water in well is deeper than thought

If the water's surface level in the well is down further than what was thought, the pump will not perform as though.

Motor is operating on wrong voltage

If motor is set to run on 230v but is only being fed 115v it will run at half speed and cannot move as much water.  Check motor label for proper voltage.  If dual-voltage motor, set voltage selector to match voltage that is actually connected to the motor.

Impeller and/or diffuser is worn

If all items above check as OK, overhaul pump:  Replace impeller, diffuser, and necessary seals & gaskets

 
 

Pump cycles too frequently

Wrong pre-charge air pressure in bladder style pressure tank

Check that pre-charge in the bladder pressure tank is set to 2 psi less than the pressure switch's turn-on setting.  Follow tank manufacturer's instructions to check tank pre-charge and adjust as needed.

Standard pressure tank is water-logged

Shut off pump, empty the tank, and restart pump. Inspect air volume controls to ensure they are working.  Check fittings and top of tank for air leaks.

Check valve or foot valve is leaking

If valve is not holding the water in the system, the water will go back into the well and pressure will drop to the switch's 'on' point.  Pump will cycle to rebuild system pressure.  In this case, replace faulty check valve or foot valve.

Pressure switch is out of adjustment

Adjust pressure switch properly or replace switch

Tank is too small for your application

We recommend minimum tank size to be enough so that the pump will run for a minimum of 60 seconds every time it runs.  If tank is small enough so that can't happen, replace tank with a larger one or install a second tank.

 
 

Pressure switch "chatters" at the end of a pump cycle

Wrong pressure in pressure tank

Check that pre-charge in the bladder pressure tank is set to 2 psi less than the pressure switch's turn-on setting.  Follow tank manufacturer's instructions to check tank pre-charge and adjust as needed.

Pump (or pressure switch) is too far away from pressure tank

We recommend the pressure switch be within ten (10) piping feet of the pressure switch.    If pump (which has switch mounted on it) cannot be that close, re-locate the switch to the piping near the tank.

Too many elbows or other restrictions between pressure switch and tank

Too many restrictions will create a pressure differential that will "fool" the switch.  Use fewer elbows, 45's instead of 90's, flexible pressure hose instead of pipe and elbows, etc.

Check valve installed in wrong place in system

Check valve needs to be in piping between the pump and the source of water (well, lake, etc.).  It cannot be in piping between pump and pressure tank.  Re-locate check valve as needed.

 
 

Pressure switch "chatters" at the beginning of a pump cycle

Pump (or pressure switch) is too far away from pressure tank

We recommend the pressure switch be within ten (10) piping feet of the pressure switch.  If pump (which has switch mounted on it) cannot be that close, re-locate the switch to the piping near the tank.

Wrong pressure in pressure tank

Check that pre-charge in the bladder pressure tank is set to 2 psi less than the pressure switch's turn-on setting.  Follow tank manufacturer's instructions to check tank pre-charge and adjust as needed.

Voltage to pump is too low

Check voltage at pump while its running.  Compare to the base voltage it is being fed.  If voltage the pump is receiving is more than 5% below the base voltage inspect your wiring for loose connections or insufficient wire size (gauge).

 
 

Pump cycles on by itself even though nobody used any water

Check valve or foot valve is leaking

If valve is not holding the water in the system, the water will go back into the well and pressure will drop to the switch's 'on' point.  Pump will cycle to rebuild system pressure.  In this case, replace faulty check valve or foot valve.

Water is leaking from system somewhere

Inspect piping, tank, toilets, household fixtures, etc. for water leaks and repair as needed

If system was "JUST" above turn-on pressure when water was last used, and an ice-cube maker ran, or toilet leaked a bit, pump will run.

Occurrences like this would be rare but could happen.  If pump runs more often by itself, see items above.

 
 
Air spurts from faucets
Pump is sucking air

Your suction pipe may have small leaks at joints, etc. where air can be pulled in.  Entire length of suction pipe and all fittings must be completely air tight(One test method is to use plastic cling wrap and wrap every joint to temporarily seal air leaks. If pump is then able to come to pressure, you have covered the leak and now must find which joint it is.)

Water level in well drops too low

Make sure bottom of suction pipe is below maximum depth that pump is capable of and/or deepest level that water is dropping to during operation.. 

Recently changed from air-over-water standard pressure tank to bladder-style tank

Pump and piping is still equipped with air volume controls and/or bleeder valves.  Remove those items.