Water Pump Won't Stop Q&A #8

Why a pump can't reach cut-off pressure or won't stop running

Well Pump Doesn't Pump Above Tank Air Pre-Charge Pressure

New Water Tank and Pump Won't Reach Above Water Tank Pre-Charge Pressure

I have had low water pressure for a while. Doing some trouble shooting I found that my foot valve was in need of replacement.

I put in a new valve system as well as a new pump. The foot valve is place at 65 feet down in my well.

There are no leaks in the piping either inside the well or coming into my home.

Unfortunately now my new pump will not build pressure past 28 psi.

My new pump is set for 30/50 psi so the amount of air in my air tank is set at 28.

That's 2 psi lower than my CUT-IN point.

I can’t figure out now what’s going on. Any suggestions? On 2020-05-23 by Mary

by (mod) - List of possible causes when the pump can't reach CUT-OUT pressure

Mary

Starting diagnostic point: measure water pressure at the tank and also elsewhere.

The fact that you see NO water pressure above the pressure tank's air pre-charge level tells me that

EITHER the pump is not working at all - not running or not developing any pressure

OR no water is entering the water pressure tank, so the pressure, measured at the water tank air valve stays at the pre-charge pressure of 28 psi.

So with the pump on and running open a faucet: are you getting good water flow? If so the the problem may be that no water is entering the pressure tank.

Next diagnostic point: with the pump turned on, does it run continuously (so we know the pressure switch isn't turning it off) or does it run for a time and then stop?

If the pump runs continuously then yes, and provided that the pressure control switch is monitoring pressure at a water pipe or at the tanktee (that is, it's not monitoring water tank pressure), then the problem is in the pump or well piping or well - not the pressure tank.

So we'll proceed with the diagnoses below:

Water pump damage: The relationship between a bad foot valve and poor water pressure is indirect.

If a foot valve leaks that can cause frequent loss of prime at the pump or pump frequent cycling. Either of those can ultimately damage the pump motor, bearings, even pump impeller, such that the pump might have trouble reaching CUT-OFF pressure.

Well Piping leak: a burst or leaky well pipe in the well or between well and house can lose so much water that even a pump in good condition may not be able to build to higher water pressure. When you turn OFF the pump, does water pressure FALL? If so there's a leak somewhere to be found and fixed.

Poor well flow rate: Very little water in the well and/or a poor well recovery (flow) rate, combined with a pump protection device like a tailpiece or a pump protection switch can also leave the pump running but not delivering much water.

Debris: Crud clogging anywhere in the pump assembly, particularly in the pump impeller assembly can also give low pressure.

Low voltage or improper pump wiring: can cause a pump to run but without sufficient power to build pressure, such as wiring a 240V pump with only 120V.

More detailed diagnostic suggestions for the case you describe are in these three tables:

• WATER PRESSURE TABLE 1: PUMP WON'T RUN, WON'T STOP, or CYCLES
• WATER PRESSURE TABLE 2: PUMP RUNS, WEAK or NO WATER PRESSURE
• WATER PRESSURE TABLE 3: PUMP RUNS, NO WATER or INSUFFICIENT WATER

Poor water pressure (weak flow at fixtures) can be caused by those conditions I list above or actually also by other snafus.

For details about other low water pressure causes see

WATER PRESSURE DIAGNOSIS

Driven point well & pump, pump can't get over 28 psi; possible air leaks?

I have Myers 3/4 hp pump that is hooked to a well point that is 13 foot down in the basement of my house.

The pump is hooked up to an 85 gallon holding tank from that I water my lawn and it all has worked fine.

Usually it can run at 40 psi and the pump shuts on and off at 30 then will pump up to 50psi.

All has worked fine in the past however, now the pump will not get over 28 psi (tank pressure and will not go high enough to cycle on and off.

The pump is fine: I just took it to the shop and had it checked out. There was a new sleeve they put in and cleaned it out etc.

I hooked it back up and no luck. I would suspect there is an air leak down in the point that is causing the problems.

I have taken the point up many times in the past and don't want to have to go through it again. Question is there any kind of sealant etc. that I can use to eliminate the air problem is that is the problem. thanks for the help 5/20/2014 howard

Reply: air leaks into well piping or low well water can cause air cavitation in the pump; find & fix the leak

Howard there may be such a product for sealing leaks in well piping by injection through the pipe interior but I haven't found it. There are putties, epoxies, mechanical devices and ven liquid coatings and sprays intended for sealing leaks from an exterior surface, and there are interior sealants intended for automotive and similar applications, not for water supply systems.

Watch out: trying to seal well piping leaks with an internal sealant product (like radiator stop-leak) has a number of risks:

• if the material is not rated for potable water containers it may be toxic to the drinking water supply
• the sealant may clog other water system components and prevent the system from working at all
• the sealant may enter and damage the pump, water tank, or water pressure control, causing unsafe conditions, even a burst water pressure tank - a dangerous event.

Using a driven point well and 85g storage tank to water a lawn sounds like an iffy design to me, unless the lawn is tiny and the watering infrequent. More likely you're over-taxing the well, which speeds the rate at which the driven point strainer tends to clog.

When a pump can't reach cut-off pressure and you suspect there's cavitation due to air in the system indeed you'd want to find and replace the leaky part.

With frequent pulling and replacing of the well point and piping I'd look out for leaks at ABS/PVC pipe connectors that have been re-used.

Sometimes we can fix such a leak by adding a second stainless steel hose clamp on both sides of the fitting; experienced plumbers don't like to re-use those connections just for this reason - they leak.

Other causes of a pump not reaching cutoff pressure include a worn or damaged impeller and even low voltage.

Water Pump Can't Pump to Higher Pressures Q&A

Water pressure is at 60 psi and my pump won't stop

My pump keeps running and pressure is at 60 psi. Help please. On 2020-11-23 by Eric

by (mod) -

Sure Eric

Here are some basic diagnostic steps:

1. Be sure that NO water is running anywhere in the building
2. Watch the pump and tank: if the pump still keeps running and never stops TURN OFF the pump - to avoid damage.
   
3. Check the water pressure switch: if it is not responding to the increase in water pressure then the switch or its pressure tube or both need to be replaced.
4. If the pump cannot get pressure over 60 psi AND if your pressure gauge CUT-OUT is set above 60 psi then the problem could be limited water flow rate at the well or a pump motor impeller assembly that's damaged.
5. Step through the diagnostic and repair procedure given at
   
   WATER PUMP WONT STOP RUNNING- topic home, and let me know what you find
   

Watch out: everyone: if a well pump runs continuously when you are not using any water you should shut it off at its power switch. It may be too late but continuous running can damage the pump parts.

Why Can't My Water Pump Reach the Pressure Switch CUT-OUT set at 40 psi?

I have a 3/4 jet pump hooked up to a 36 gallon pressure tank , 500 gallon water tank.

The pump kicks on but will not reach shut off pressure at 40psi.,

The pump stops at 25psi for a few seconds then kicks back on.

It keeps repeating this.

Seems to thermal overload; the pump is new, pressure tank is new , all new plumbing in pump house , no leaks visible.

Any ideas why pump will not reach pressure , house is getting a little water but it just runs out and pump will not kick back on until safety switch lets it . If you have any idea it would be greatly appreciated, thanks On 2020-02-28 by Jonny

by (mod) - pump won't reach 40 psi cut-off pressure

Jonny

That pump stopping at 25 psi and kicking back on could be itself triggered by

• a leak in well piping
• a pump that can't get ahead of the leak
• a pump that can't deliver water as fast as you're running it (e.g. with several faucets open at once)
• or for other reasons can't reach the cut-off pressure - given in detail in the water pump won't stop running article linked-to below.
  
  Let's start with the diagnostic suggestions

at WATER PUMP WONT STOP RUNNING

take a look and let me know what you think

Installed New Pressure Control Switch: now pump won't get above 40 psi and pump won't turn off

I replaced a 20 - 40 pressure switch with a 40 - 60. During the removal process and water removal I depleted the air supply from the tank to reduce the pressure of the water. The line pressure wont get above 40 and runs continuously. Was that an oops to bleed the air off? How do you restore proper pressure for the tank? On 2020-01-03 by Dan

by (mod) - be sure your water tank air charge is set, while empty, to the right pre-charge pressure

Bottom line: if your pump runs continuously and can't get above 40 psi I suspect that there's a problem with the pump or well or well piping.

It's okay to have removed air from a pressure tank since I would expect that the same valve that you use to remove it would allow you to pump the air charge back in.

Typically we release pressure on the system by shutting off the pump and simply draining water pressure by opening nearby faucets.

With the pump off and having run water until there's no pressure in the system you want set the tank air pre-charge to 2 PSI below the pressure switch CUT-IN pressure.

After Flooding the Pump Runs & Won't Shut Off

Could a leak at the water pump or a pump that ran so long it flooded the basement now cause the pump to not turn off?

I have a shallow well with a jet pump. Just replaced pump and it won’t shut off.

Water coming from the well flooded my basement, so I did not prime the pump as it should have primed it self.

Now the pump will not shut off. And I see a small leak on discharge side of pump. Could this be the problem? On 2019-11-14 y Marty

by (mod) -

Yes, Marty a leak in the well piping or anywhere else at the pump, when the well pump is off, can cause the pump to lose prime. So yeah that could be the trouble.

But I have some other concerns here:

Watch out: the pump having been "under water" - by your description - could well have damaged the pump's electrical components. Safest advice would be to leave the pump off and have the motor checked out by a motor repair shop. There are shock risks here.

Watch out: But also if you ran enough water previously to flood the basement of your home, and if the pump burned-out from that unfortunate event, then IF your new pump went in quickly - say in hour THEN it's possible that also the well was exhausted and needs more recovery time.

Or it's possible that you needed to prime the pump. Being "under water" doesn't prime the pump, as its interior chamber is not open to your basement.

Water Pump Won't Stop: Failed Well Q&A

My Pump Wouldn't Stop Running: the tech says I need a new drilled well

My pump began running non stop and when the well person came out they said they were able to set psi to 38 and the pump would shut off correctly however most likely the jet is plugged or a hole in casing for it to change suddenly and It will eventually just quit.

Does this sound correct. It is now functioning fine at 38 psi but I am concerned since winter is coming and I shoul get a well drilled now. I am not planning in investing in repair if it needs repair because it's an old 2" - Amanda 8/26/12

Reply:

A hole in a well casing may admit dirt and contaminants and might speed up clogging of the well screen on a foot valve or pump pickup;

But some more accurate diagnosis is needed before drilling a new well.

For example: if the problem is a damaged well casing, there are well sleeves that often can fix that problem without going to the much greater expense of a whole new well.

Well Pump Could Not Reach CUT-OUT Setting, Pump Died

I increased water pump pressure switch settings, pump kept running, then quit entirely

Last week I increased the cut-in cut-out pressure switch setting on my well.

The system was running at 20-40 and after making the pressure switch adjustment it has been running at 40-60 just as I planned. I checked the cut-in and cut-out over several days after the change and it was working fine.

Today we found that we had zero water pressure. I looked over our system and found there is no water flowing into our pressure tank so no water is being pumped.

I tested for power at the pressure switch and it is getting power but I did not check the voltage. The well pump was here when we bought the house about 10 years ago so the pump is at least 10 years old.

I don't know the specifics of the pump but the control box for the pump states 1 hp, 230 volt, single phase and includes a capacitor and some other blue device. I assume my increasing the pressure switch seating has lead to a pump failure. Anything else I should test before running out to buy a new pump? - John M 8/34/11

Reply:

John M:

Changing a pump pressure control switch from 20/40 all the way up to 40/60 has an understandable appeal: much higher water pressure, faster flow rate.

But the risk is that you set a cut-off pressure that the pump simply cannot maintain. If that happens the pump might just keep on running - never reaching that 60 psi.

If your pump overheats it could be that its motor tripped off on thermal overload.

If your pump was a submersible you might not know that the pump is spinning itself to death down in the well. Until it stops working or until the pump overheats and shuts down on thermal overload. Some, but not all, electric motors have a resettable ELECTRIC MOTOR OVERLOAD RESET SWITCH

A second possibility is that sometimes when we start pumping water out of a well faster than before we can exceed the well's flow rate (especially if the well is not very deep- doesn't have a big static head). Even if the well later recovers, we can lose prime and lose water pressure, or in some cases run the pump dry and damage it.

Sorry about the bad news, but those are the worries that occur to me from your description.

Followup:

Thanks for the reply Dan,

The pump is working fine now, the following morning after my post I replaced the thermal protection device, turned on the pump and it immediately started pumping and has been running fine since.

Just for clarification and as I explained in my original post, the pump is cycling properly (cutting in and out) with the higher presser setting of 40~60 psi.

I suspect the problem occurred due to my extended continuous use of water while I was working on a landscaping project which had the water running continuously for 8 plus hours. It appears the thermal protection device which is designed to protect the pump from burning out did its job.

Happy to report the pump and well are working great.

Reply:

Thanks John M - I will add "replace the thermal protection device" to our list of diagnostic suggestions when a pump motor won't run. Can you send along photos of the parts and pump? Use the CONTACT link found at page top, left, bottom.

Water pump takes a long time to reach the cut-off pressure

Once faucets are shut off, pump will run 10 to 15 minutes, then shut off. Shallow well one line system - (Feb 3, 2014) Mike

Reply: set the CUT-OUT pressure down a bit

Mike, that's a bit long just to re-pressurize the water tank. Could be that the well yield has diminished or there could be a well piping leak. Or you could have a huge water storage tank.

Before messing with anything else I'd check that the cut-out pressure is not set just a little too high. If we set the pressure control switch cut-out at the very edge of what the pump can deliver then we might get a long on cycle. Try just backing off the cut-out to a few psi lower - OR tell us the pressures you're seeing on the gauge.

Tankless Water Pump System: Pump Won't Stop Running Q&A

ZDS pump in my bore hole with no pressure tank: pump won't turn off when we turn off water

I've got a ZDS pump in my bore hole and it requires no pressure vessel. We have had the filter and back wash system moved. Since the move the pump will not switch off when we turn the water off. If I turn the incoming stop tap off then the pump stop. If I turn the stop tap off to the backwash tank it carries on.

The pipe work has been fitted with an inverted " U". Could it be air any ideas I think it may be air trapping in the "U"? 1 Feb 2015 Anonymous

Reply:

I suspect the pump's pressure and flow sensing control is debris clogged or has failed.

ZDS Innovation sells pumps throughout much of U.K. Europe, and some of Scandanavia. You might want to contact the company - nearest office to you or through their contact information I can give just below:

ZCS Innovation pumps: ZDS srl - Via Grecia 8 - 35127 Padova Z.I. - Italy - Company Registration Number: PD – 402204 - Tel: +390497994854 - Email: info@zdsgroup.com
Wegsite: http://www.zdsgroup.com/

More diagnosis and repair details are at

• WATER PRESSURE BOOSTER PUMPS 
• GRUNDFOS SCALA 2 PUMP GUIDE - field reports on performance of a Scala2 booster pump

This article series 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.