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This website answers just about any question you may have about pumps, wells, and drinking water. Even before performing water quantity, quality, equipment function tests, there is an enormous amount we can determine about
a building's water supply just by looking at the equipment.
Articles here provide details on water pumps, tanks, controls, and wells and water supply inspection, diagnosis, and repair.
The photograph shows a one-line jet pump, the water pressure tank, and a water softener. We know from the fact that this is a single line jet well pump that the well is a shallow one, probably less than 27' deep. Well depth may have implications
for water quantity and quality and vulnerability to surface water contamination.
Watch out: the first thing to do to protect your pump from damage if it simply wont' turn off is to shut off electrical power to the pump. If the building has no water pressure, turn off the water pump immediately. Running a water pump "dry" risks causing internal damage to the pump. If there is no water pressure, see WATER PRESSURE LOSS DIAGNOSIS & REPAIR.
If your building has some water pressure (check at a nearby faucet) but the well pump keeps on running and won't shut off, that's what we are discussing here. Several problems can cause a water pump to keep running instead of shutting off when it should, and each of these suggests its own diagnostic step to finding out what's happening with your well pump.
Water may be running somewhere in the building. Check for a running faucet or fixture indoors, including checking for running toilets. Remember to check outside garden hoses and watering systems. If all fixtures are turned off, make sure that you don't have a burst pipe somewhere. Remember to check heating boilers and water heaters for leaks too.
The well pump may have lost prime. See WELL PUMP PRIMING PROCEDURE for two methods that almost always work to get a dry well pump going again. Make sure that you have adequately primed the pump and do not let a well pump run dry - you are likely to damage it.
The pump pressure control switch may be set to a higher pressure than the pump can achieve - this is more likely if someone has been fooling around with the switch. See Water Pressure Adjustment how to adjust the water pressure in a building.
The well water level may have dropped and the pump is unable to pick up and deliver water in sufficient volume - this is possible if the well piping has a low-water tailpiece installed to protect a submersible pump from burnup. In this design if water level in the well drops too low the tailpiece causes water to re circulate through the pump rather than being sent up the piping to the building served by the well. See these articles: Well Flow Rate, Well Yield, Well Water Quantity: How Much Water is In the Well? Well Flow Rate, Yield Improvement Methods How to Get More Water From a Well without drilling a new well, and see Well Life Expectancy of Wells how long should a water well and its components last?
The pump may have suffered internal damage to a seal, bearing, or impeller. The motor will keep running but the pump is unable to develop normal pressures. See Life Expectancy of Water Pumps - Well Pumps: how long should a water pump last? What affects pump life?
The well piping may have a leak. This includes "hidden" leaks such as a leak in the piping inside the well or between the well and the building. If such a leak is present you may observe that water pressure in the system drops when the pump is turned off even though no water is running in the building.
A leaky foot valve in the well or a hidden running water source in the building such as a running toilet can also cause this symptom. See Repeated Loss of Pump Prime for a discussion of well piping foot valves and the relation to loss of well pump prime.
A failing well piping low water cutoff control or well tailpiece intended to protect the well pump from damage by a low-flow or poor recovery rate well may have failed or may be needed. See WELL PIPING TAIL PIECE for details.
The well pump output rate may have exceeded the well's safe flow rate, or a well drawdown cutoff device or tailpiece in the well may have failed (or may be needed and missing). See WATER PUMP TYPES & LIFE EXPECTANCY where we describe these conditions and parts.
Table of Diagnostic Steps for a Well Pump that Won't Shut Off
Watch out: the first thing to do to protect your pump from damage if it simply wont' turn off is to shut off electrical power to the pump. If the building has no water pressure, turn off the water pump immediately. Running a water pump "dry" risks causing internal damage to the pump. If there is no water pressure, see WATER PRESSURE LOSS DIAGNOSIS & REPAIR. Some of the well pump troubleshooting suggestions in this list can be found at the Betta-Flo Jet Pump Installation Manual from the National Pump Co.
What to Check if the Well Pump Will Not Stop Running
Pump Won't Stop Cause
Diagnostic Procedure
Repair Procedure
Water running in the building
If water is running somewhere in the building water supply system (don't forget outside garden hoses and lawn sprinklers) at a rate faster than the pump can deliver from the well, the pump will run continuously.
Turn off the main water supply to the building, typically found at the water pressure tank. If the pump continues to run the problem is not likely to be a running fixture or pipe leak downstream (in the building) from this point.
If you have turned off water at the water pressure tank and the well pump is still running, before blaming the pump, controls, piping, well, lookonce more for water supply piping that may be ahead of the valve where you turned off water.
Turn off or repair running toilets, outdoor garden hose hook-ups or lawn sprinklers, or supply piping that is leaking.
If this was the problem source the well pump will continue to run until pressure builds up to the pressure control switch cut-out level and the pump should stop.
If the pump runs on, check the remaining diagnostic steps below.
Lost prime at the well pump
If the above-ground (jet pump) pump has lost prime the pump may be running "dry" continuously.
Watch out: turn off the pump immediately to avoid damage.
If no water is being delivered and the pump is running and it's an above ground pump, turn off power and inspect the pump cavity for the presence of water by removing the priming plug.
If the pump is a submersible unit in the well, loss of prime is not normally an issue.
A bad check valve or failed foot valve can lead to loss of well prime.
Improper switch adjustment can cause too-rapid pump cycling
If you or someone else has tried "adjusting" the cut-in or cut-out settings of the pressure control switch, it may be set improperly.
Check / change pressure switch pressure settings to correct adjustment for cut-in and cut-out. Normally we see about 20 psi between cut-in and cut-out pressures.
Lower the pump cut-out pressure setting. If the pump stops, this was the problem.
If the switch is not responding consistently to changes in building water pressure the pressure-sensing component of the switch or the tubing connecting it maybe defective.
Try removing the tubing and blowing air through it.
Check pressure switch tubing for leaks or clogging. Clean or replace the tubing.
The clog could also be debris in the orifice on the bottom of the pressure switch sensor, or inside the sensor requiring that the switch be replaced.
Water pressure switch contact points burned/welded
Arcing may have burned the pressure control switch contacts. In some cases the contacts may become "welded" together in the closed (power on) position.
Turn off electrical power (for safety) and examine the contact points. If they are stuck together and burned this may be the problem.
A bad leak anywhere in the well piping between the building water pressure tank and the bottom of the well can leak enough water when the pump is running that the pump cannot raise pressure in the pressure tank up to the cut-out level and the well pump will continue running.
Close the main building water supply valve between the pressure tank and the rest of the building.
Turn off the well pump electrical power.
Watch the water pressure gauge. If pressure continues to drop there may be a leak in well piping. If the gauge does not move, tap it to be sure the gauge is not itself stuck.
Also air coming out of building plumbing fixtures can be caused by air leaks into the same well piping when the pump is not running.
Leaks in well piping will usually require pulling the piping in the well and if no leak is observed there, it may be necessary to excavate along the path of the well line between well and building. Start excavation by looking for wet spots on the ground that could be caused by a well piping leak.
If the well water level has fallen too low or the well recovery rate is too poor, or if the well pump is oversized for the well flow rate, the pump may run continuously.
Other symptoms of this problem include air discharge at plumbing fixtures.
Install a properly-sized well pump matched to the well flow rate.
Install a tailpiece and/or low water cutoff device to protect the pump from damage.
Investigate and fix the cause of a poor flow rate or low-yield well.
Plugged ejector assembly, tailpiece,or foot valve or well screen in the well
Debris clogging the screen at the water pickup in the well can reduce the water flow rate.
To diagnose and correct this problem it is necessary to pull the well piping and inspect the ejector, tailpiece, foot valve or well screen for clogging
A well pump that cannot pump water pressure up to the pressure control-switch cut-off point.
If you are confident that none of the explanations above diagnose a well pump that runs on, check that the pressure gauge is itself accurate - that's how we make sure that the pressure control switch is not set above pump capacity.
Having eliminated all of the explanations above, we suspect the pump may have become internally damaged and it will need repair or replacement.
Turn off electrical power to the well system, remove system water pressure (save water for pump re-priming if necessary).
Remove and inspect the well pump and pump motor for proper operation. Check the pump impeller assembly for mechanical damage, broken internal parts, or mineral deposits or debris clogging that reduce water flow through the pump.
Replace the impeller assembly and other pump parts as needed or replace the entire pump assembly.
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Betta-Flo Jet Pump Installation Manual, National Pump Co., LLC., includes helpful well pump troubleshooting tips as well as basic jet pump installation details. Web search 07/15/2010, original source: http://www.nationalpumpcompany.com/Documents/OIM/Betta%20Flo%20IOM%20Jet%20Pump.pdf
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