Questions & answers help diagnose and fix water pump short cycling on and off:

Frequently asked questions about rapid on-off cycling of a well pump or water pump or its pressure control switch.

This article series explains how to diagnose all of the various causes of well pump short cycling - what causes the well pump to run too often or to turn on and off too rapidly.

Common Causes of Well Pump Short Cycling: how to diagnose & fix well pumps turning on and off too often

These recently-posted questions & answers about diagnosing a short-cycling well pump or pump control switch were originally discussed at WATER PUMP SHORT CYCLING CAUSES - be sure to read that article.

Short cycling of a water pump which is defined at SHORT CYCLING WATER PUMP means that the water pump or "well pump" turns on and off too rapidly or too frequently when water is being run in the building.

If this is the problem with your water pump, this article (below) describes the most common causes of this problem.

The most-common cause of pump short-cycling is loss of air in the water pressure tank.

If you have no water flow (no water pressure) at all, see NO WATER PRESSURE

Or try these three water and pump diagnostic guides

• 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

On 2016-11-29 9 by (mod) - water flows back into cistern after pump stops

Check for a bad foot valve in the well

On 2016-11-29 by Jared

My pump operates normally, but once the tank is filled with water and the pump shuts off, the water is pushed back into the cistern and the pump turns back on when it reaches the proper low end pressure.

On 2016-11-27 by (mod)

IF your tank uses an internal bladder AND IF the air valve is mounted on the tank (not on water piping) THEN yeah, if water comes out that suggests a leaky or torn internal bladder.

On 2016-11-27 by Rick

I checked the pressure in the bladder tank. When I checked it was 43psi but water came out as well. Shouldn't it only be air?

On 2016-11-08 by (mod) pressure drops after pump turns off

John:

Check for a leak in well piping or foot valve if you can by shutting off a valve between well and pump (don't let the pump keep running or it'll be damaged). If the pressure drops then there's a leak on the house side. If pressure doesn't drop but does when you open the valve again then there's a leak in well piping or foot valve.

On 2016-11-08 by john

I have lotsa water but immediately after pump shuts off at 50 it drops to 30 n refills my tank, this happens a few times every minute. And no water is running anywhere in the house. Where's goin,bad check valve? Or is this a bad bladder?

On 2016-10-22 by (mod)

Anon

In a separate article found by searching InspectApedia for WATER PUMP INTERMITTENT CYCLING you'll find the diagnosis and repair for this problem at https://inspectapedia.com/water/Intermittent_Water_Pump_Cycling.php

On 2016-10-21 by Anonymous

My pump keeps coming on and off all the time even at night when everybody is in bed

On 2016-10-12 by Toever

My well pump was short cycling. Changed the switch and gauge. Seemed to help except, when the pump cut in the hose and well cap would jerk and jump violently.

Pressure jumped instantly to 70 and cut out. Today I checked pressure in tank - Cut in is 40 psi and the tank was 45 so I dropped it to 38. Still short cycling. Stitch is 40/60. I would empty the tank and start over but afraid of the way the pump will react (jumping violently).

On 2016-09-28 0 by (mod)

Anon: your well pump is short cycling as described in the article above.

On 2016-09-28 by (mod)

David:

"Dry" may be a relative term. But if you can only pull 45 -50 gallons before running out of water, that's close to "dry" in well-world.

Take a look at the recovery time: how long do you have to wait before you can pull another 50 gallons? You might be able to install a holding tank that gets filled at a very slow rate, overnight, thus surviving a bit longer with an inadequate well.

Search InspectApedia.com for WELL FLOW RATE to read about how to make an accurate, objective measure of the well's ability to deliver water.

On 2016-09-28 by Anonymous

water pump runs in a short cycle. if i open the faucet the pump will in short and off like pulse

On 2016-09-04 by David

Yesi have a question because the well guy I had come out and look at it says the well is dry. I don't beleave that reason being the water will work I can use about 45 to 50 gallons and then it quiets working

I can go flip the breaker and wait about 30 to 45 min and flip breaker back on and poof I have water again but I use 45 to 50 gallons it will cut off so I left it on this time did not flip breaker another water will flow through the sink and stop for about 5-8 min then the water will flow again and cut off it will burn my pump up so I keep going to flip breaker so it want burn my pump up does any one have a suggestion

On 2016-09-03 by (mod)

If water comes out of an air valve on the tank itself then the tank is waterlogged or if it's a bladder type tank the bladder has probably leaked or burst.

On 2016-09-03 by Anonymous

My pump runs for about 2 seconds and then shuts down. It turns on about every minute or so. Can I test the air pressure by pushing the pin on the air inlet valve? If water comes out is that an indication of no air pressure? And should air be leaking out when I press that pin? The tank does build up pressure if no water is used for awhile.

The short cycles will eventually build pressure, but obviously doesn't hold because the pump will only run for about 2 seconds, regardless if the water is running or not.

Both the tank and the switch aren't that old. Maybe 4-5 years, 6 at the most.

On 2016-07-05 by (mod)

If you are pumping into a closed system, that is there are no fixtures running water and no piping leaks, then if the pump can't reach cut-off pressure I suspect that the pump impeller is clogged or damaged.

On 2016-07-04 23:32:22.950801 by David Witham

Pump system feeds camp from lake (non-potable). System 40 yrs, old been updated in Spring often. This year could not get to raise pressure to 50. Bought and installed new pressure switch, gage and bladder tank; still can not get pressure above 26 lbs. Pressure drops to 0 them pumps again to 26 and recycles.

On 2016-06-30 by Anonymous

Can iflush pump and 1line pipe by taking hose from house to flush and prime pump at the same time

On 2016-06-21 by (mod)

5-20 years - check the water tank warranty;

Having to force the pressure switch on to run the pump sounds like a switch problem.

On 2016-06-20 by dave wolfenden

does have an idea of the life span of air tank with a bladder replaced the pressure switch . switch will not hold if i hold the lever on the side it comes on and shuts right off any ideas would be helpful

On 2016-05-23 by (mod)

Check for

= debris in the tube conducting water pressure to the pressure sensor port on the switch base
= a slow leak in a check valve or foot valve
= water running in the building

On 2016-05-23 by Don

1/2 HP Water pump Goulds New switch 30/50. Pump kicks on and then goes off and then a minute later kicks on and goes off

On 2016-05-22 by Chris

I installed a new 1/2 horse shallow well pump and 20 gallon tank. Water is not from a well but gravity flow from a 10,000 gallon elevated tank 300 feet away

The pump runs fine until it builds up pressure to 55 lbs and then starts to turn on and off rapidly until it blows the breaker if not shut off. Replaced the new pressure switch.

Lowered the tank pressure to 28 lbs of air as reccomended by the pump instructions. No luck. why won't it stay off when pressure is reached?

On 2016-05-10 by (mod)

Anon:

The pressure tank for your system may be waterlogged.

On 2016-05-10 by (mod)

Re-posting a comment made on an older .htm version of this web page

AUTHOR:Anonymous (no email)
COMMENT:Why does the pump come on as soon as you flush the toilet? it goes off right away, but shouldn't you be able to run a few gallons of water before the pump kicks on

On 2016-04-11 by (mod)

Lonnie,

I don't think that a well pump that's short cycling (turning on and off rapidly) would be likely cause the hot water temperature to vary rapidly: I'd look for a sticking or defective anti-scald device.

On 2016-04-08 by Lonnie

My water in my house is getting cold then hot when we take a shower we have a well and we have never had this problem before anyone have a answer to this problem?

On 2016-03-13 by (mod)

Kristina the pump gauge should not contain water - it's leaky and needs to be replaced.

Watch out: left in place the leak could become worse and could enter the building. Basically you remove water pressure from the system - you don't have to drain it dry if you don't mind getting wet and spilling a little water - then you prepare a new gauge, then remove the old one and put in the new one in the same spot.

Details are at https://inspectapedia.com/water/Water_Pressure_Gauge.php

On 2016-03-13 by Kristina

Hi, my pump gauge is full of water. It's new. The pump is not cutting in properly. Not much water. What can I try to fix this.

On 2016-02-29 by André

I have a 80 liters tank horizontal with a bladder type.
It seems that I do not get a lot of water in reserve.
My system starts at 40 and shuts off at 60 pds.

I have the air pressure at 38 pds.

I still do not understand why it should be lower by 2 pounds and not the opposite , like 42 pounds for 2 pounds extra.
Because I guess that before the tank empties itself the pump starts to operate before the water gets out???

because the water pressure is higher and keeps the water inside the tank.

On 2016-02-06 1 by (mod)

Ron,

Thank you for a great question, one I've never heard. I don't know the answer. Please let me know what your plumber finds.

It sounds as if the pressure tank is simply totally ineffective - as if it is blocked from the water piping system.

On 2016-02-06 by Ron

Had a new jet pump installed about 1.5 years ago. All was well until about a month ago. Everytime we turn on a faucet, use the washer, flush, etc., the pump comes on for a few seconds. Never happened before.

Used a tire pressure gauge and the psi on the old WELL-X-TROL reads 45. Any ideas before I call the plumber.
Great site

On 2016-01-07 by (mod)

John, unless the water tank is a special model it is not intended to be installed on its side and doing so makes failure likely. It's possible that the internal bladder of this tank has been damaged or burst.

On 2016-01-07 00:07:38.144624 by John Miller

I have a friend who has a weltrol tank on it side outside and there is an air leak ..it is also short cycling...it was installed laying down ,,not sure how long its been that way atleast 4 years ....Could it be a hole in the tank or bad bladder it is a weltrol wx 202

On 2016-01-06 by (mod)

When the water tank is a type that uses an internal bladder, you can't let the air out of the tank unless you do so through the air valve on the tank top. So if the pump is short cycling the problem may be that the bladder is burst or stuck to itself in the tank.

Sometimes we can push the bladder open again by briefly pushing the pressure up a bit at the tank - but take care not to exceed the maximum rated pressure the tank can contain or it could burst and kill someone nearby.

On 2016-01-06 by Courtney

Sorry for so many of these it is a Well-x-troll WX203.

Sorry is cycles 4 times for every time the toilet is flushed.

Last week we replaced both of our hot water tanks. My husband let ir out of our well tank accidentally. I noticed the well short cycling.

So we added air to 28 psi we have a 30/50 switch. But it is still short cycling if we flush a toilet it clicks on/off at least twice. Any help would be greatly appreciated.

On 2016-01-03 by (mod)

Sharon:

As the pump itself doesn't know where water is being run, I suspect that it is the flow rate that is affecting the short cycling you describe. In any case check for a waterlogged pressure tank.

On 2016-01-02 by Sharon

OUR pump kicks on about every 20 seconds when we are running water upstairs in the bathroom...including sink, bathtub and toilet...this does not happen in the laundry room or kitchen..this is a tri level.,can you help

On 2015-12-08 by (mod)

Joey: in the article above we list common causes of short cycling water pumps; the most usual cause is loss of air charge in the pressure tank.

But if a pump is cycling on and off rapidly but at each cycle increasing the final pressure in the tank I suspect that the tank inlet is blocked.

On 2015-12-07 23:10:14.477935 by joey

Sorry didnt put my name in last comment.

On 2015-12-07 by Anonymous

Oh yea this is a new 3/4 horse submersible pump with new check valve, 30/50 pressure switch, and bladder tank with 28 psi.

On 2015-12-07 by Joey

Pump is short cycling constantly while building pressure and my pressure switch is about 25 feet from presssure tank. Could this be the problem?

On 2015-09-19 by (mod)

IF the pump is turning on and off every few seconds it is short cycling - the common causes with links to repair procedures are in the article above. Check first for a waterlogged pressure tank.

On 2015-09-19 by Larry

I replaced water pressure valve switch and now when the water is running it kicks on and off until the water is cut off.What do I need to do to fix this issue? Thanks

On 2015-09-19 by Anon

Thanks for this information.

On 2015-09-15 by Valarie

Hi,
Last night in the shower the water turned completely off for about 30 seconds and then would come back on for 30 seconds.

It did this maybe 10 times. Is that what is called short cycling? I have water today, but when I turned the washer on and the sink at the same time, the sink water did not come on.

My husband took a fine shower this morning, so he's thinking I'm crazy. Please help us to start somewhere, we're not extremely knowledgeable about our well pump. Thank you!

On 2015-09-15 by nylan

Hi.
I recently installed new water lines, pressure tested to 60 psi and held fine before the pump. It's picking up water but keeps rapidly kicking on and off without any water being discharged? (Out of the tap) Besides the pressure control switch what should I be checking?

On 2015-08-11 by (mod)

Very good going, Dave, that problem can be tough to find.
A gate valve knob will spin and it's not always obvious if the velve internal body is moving or not.

Thanks so much for the feedback, that will help other readers. I'll be sure to merge your finding into our tips.

DF

On 2015-08-11 by Anonymous

Thank you I checked the gate valve and found the gate had come off the stem. I replaced it with a ball valve, No more problems.I will be telling my frends about this site.

On 2015-08-10 by (mod)

Dave:

I'd be looking for an obstruction such as a nearly closed or blocked valve.

But even better, watch the pressure switch. It's possible that water is not entering the tank or that your tank is waterlogged and includes a pressure gauge that's stuck, giving a false reading. Gently rock the tank (don't break any connections) and you can usually tell if it's empty (it'll be light), and similarly, if no water is entering the tank its pressure and temperature and weight wont' change.

On 2015-08-10 by Dave

My water pump is cycling on and off,every 2-3 sec. when a tap is opened. I have replaced the switch with a 20-40 psi switch and checked that the pressure tank ( bladder type ) has 18 psi in it.. any ideas would be helpfull. Tks

Question: I got rid of my pressure tank and now am having trouble with short cycling.

(July 5, 2015) Mike Lambadarios said:
Have had problems with water supply ended up doing away with the header tank and pressurised the system directly to the house.

Ran fine for quite a while but is now constantly short cycling,I removed the bladder tank and blocked off the fitting again ran fine for a while but now back to short cycling again. Was it a mistake to pressurise directly to the house and shoul;d I reinstate the header tank?

Reply: either install a water pressure tank or install a pressure-sensitive water pump system.

MIke

Pressure-sensitive water pumps

You need either a pressure tank installed to prevent short cycling of the pump, or you need a special hydropneumatic pump control that combines the pump with a pressure switch - shown at left. This is essentially is a switch that can turn a pump on and off when needed without short cycling.

In our photo at left that silver domed gadget above the red pressure-sensitive water pump works with the silver micro-pressure tank to provide a boost to water delivered (typically) from a rooftop water tank. No water pressure tank is used with this system.

These systems are typically used as water pressure boosters and not as the primary water source pump.

The little silver dome dome is a miniature pressure tank itself, pre-charged to 7 psi and the whole system is calibrated to avoid short cycling of the water pump.

This equipment is distributed by bombasrowa.com and is widely distributed in Mexico where often we want simply to boost the pressure delivered by a rooftop water storage tank. Keep in mind that the total flow rate and building water service from this sort of system is of limited capacity.

Often we see pressure sensitive water pumps or inline pump controllers used with rainwater harvesting systems and cisterns or rooftop water tank systems serving small buildings. Submersible models of these pumps are also available for installation in the water tank.

Similar devices are sold by Aqua Group in India: the Aquatex APS hydropneumatic system. This approach floats a very small internal-bladder type pressure tank atop the water pump. Other models are used in marine applications such as the Shurflo and the Jabsco.

Inline pump controllers to avoid using a pressure tank

A third option might be to use an in-line pump controller. An inline pump controller can be added to an existing system and works with most water pumps. The inline pump controller senses pressure changes similarly to the pressure-sensitive water pump system we described above, and turns the pump on or off as needed.

Some inline pump controllers include an additional sensor to shut off the pump if the water supply is lost, thus protecting the pump from damage.

Pressure sensitive pump references & sources

• Arnette, Henry K. "System for protecting a liquid pump." U.S. Patent 5,244,351, issued September 14, 1993.
• AQUASUB ENGINEERING (Corporate Office) Thudiyalur (post) Coimbatore - 641 034. Tamilnadu, India Phone: 0422-2642484 Fax : 0422-2642128 Email : aquasub@vsnl.com
• Bynum, J. "Pressure sensitive control for pump regulator." U.S. Patent 3,794,789, issued February 26, 1974.
• Bell & Gossett: commercial grade and sized inline pumps, http://bellgossett.com/pumps-circulators/in-line-pumps/
• e-LNE in-line pumps, capable of higher flow rates than the small systems we discussed in the article above,Xylem Water Solutions UK Limited Main Office Millwey Rise Industrial Estate Axminster Devon EX13 5HU – UK Tel: (+44) 01297 630210 Fax: (+44) 01297 630295 E-mail: lowaraukservice@xyleminc.com http://www.lowara.co.uk/
• Grundfos high efficiency in-line pumps: http://net.grundfos.com/Appl/WebCAPS/Grundfosliterature-3847.pdf
• Rainwater Harvesting Ltd Unit A Harrier Park Southgate Way Peterborough Cambridgeshire PE2 6YQ General enquiries call +44 (0) 1733 405 111 Fax: 01733 230 996 info@rainwaterharvesting.co.uk

Question: pump keeps stopping

(July 5, 2015) Peggy said:
we just had a new pump and pressure switch on Saturday, it is doing the same thing. It will run for so long and then just stop, no water at all but when it comes back on, it full force no trickle....any ideas?

Reply:

Peggy

If we are sure that the pump is good and it runs but no water is delivered the pump may not be primed properly. If you leave it running it can be ruined - even though new.

Then see if there is a disconnected or leaky well pipe or there is no water in the well. Perhaps a blocked well screen or foot valve could also be at fault.

Question: water pump is cycling on and off,every 2-3 sec. when a tap is opened

10 Aug 2015 Dave said:
My water pump is cycling on and off,every 2-3 sec. when a tap is opened. I have replaced the switch with a 20-40 psi switch and checked that the pressure tank ( bladder type ) has 18 psi in it.. any ideas would be helpfull. Tks

Reply:

Dave:

Watch the pressure switch. It's possible that water is not entering the tank or that your tank is waterlogged and includes a pressure gauge that's stuck, giving a false reading.

Gently rock the tank (don't break any connections) and you can usually tell if it's empty (it'll be light), and similarly, if no water is entering the tank its pressure and temperature and weight wont' change.

If you are dead certain the pressure tank accepts water and is being pumped up I cannot imagine why you'd have sort cycling every 2-3 seconds. I'd be looking for an obstruction that lets water into the tank such as a bladder stuck on itself or a nearly closed or blocked valve.

Our complete diagnostic list of all known causes, diagnostic steps, and repair procedures for well pump short cycling is

at WATER PUMP SHORT CYCLING DIAGNOSIS TABLE

If you are not sure what "water pump short cycling" means or how it is recognized, see

SHORT CYCLING WATER PUMP.

Intermittent water pump cycling which is discussed at

INTERMITTENT WATER PUMP CYCLING When No Water is Running means that the water pump comes on for no apparent reason.

Loss of water pressure means that the pressure with which water enters a plumbing fixture has become too slow, or is sometimes too slow or weak in water flow rate, or water flow may stop entirely.

See WATER PRESSURE LOSS DIAGNOSIS & REPAIR

...

Continue reading at WATER PUMP SHORT CYCLING CAUSES or select a topic from the closely-related articles below, or see the complete ARTICLE INDEX.

Or see WATER PUMP SHORT CYCLING CAUSE FAQs-2 - more-recent Q&A about rapid on-off cycling of a well pump

Or see these

Recommended Articles

• WATER PUMP SHORT CYCLING CAUSES
  • WATER TANK AIR CHARGE LOST
  • WATER PUMP PRESSURE CONTROL SWITCH
  • WATER PUMP WIRING REPAIR - separate article
  • WATER SUPPLY PIPING BLOCKED
  • WATER FILTER CLOGGED
  • WATER TANK AIR OVERCHARGED
  • WATER TANK BLADDER DAMAGED
  • WATER TANK BLADDER STUCK to ITSELF
  • WATER TANK LEAKS
  • WATER TANK LOCATION DISTANCE & SWITCH CHATTER
  • WATER TANK or TANK TEE FROZEN
  • WELL PIPING / CHECK VALVE / FOOT VALVE
  • WELL PIPE LEAKS
  • OTHER CAUSES of WATER PUMP SHORT CYCLING
• WATER PUMP SHORT CYCLING DIAGNOSIS TABLE

Suggested citation for this web page

WATER PUMP SHORT CYCLING CAUSE FAQs at InspectApedia.com - online encyclopedia of building & environmental inspection, testing, diagnosis, repair, & problem prevention advice.

Or see this

INDEX to RELATED ARTICLES: ARTICLE INDEX to WATER SUPPLY, PUMPS TANKS WELLS

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Citations & References

In addition to any citations in the article above, a full list is available on request.

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