Water pump short cycling diagnostic FAQs:

This article provides answers to frequently-asked questions about how to diagnose short-cycling problems with a water pump or well pump.

If the well pump runs too often or cycles on and off rapidly these diagnostic questions should help troubleshoot the problem.

Questions & answers about well pumps or water pressure pumps that run too often (short cycling)

On 2018-10-01 by Nick

I have a 1/2 hp GE 5KC36HN2934AX well pump with a SQUARE D Pumptrol 20/40 low pressure cut off switch.

There should be 18psi in the pressure tank WM-9. I haven’t checked. For some reason the cut in switch is kicking in at 30psi and cutting out at 40psi.

Also there is a very faint squeal while running and the guage is jumping up and down until it hits 40 psi and stops. Could the bladder in the bag have a leak and the bearing be going in the pump?

On 2018-10-01 4 by (mod) - squealing noise at the pump is a failing bearing.

Nick

I suspect that the squealing noise at the pump is a failing bearing.

I hate hate and dislike suggesting that there are multiple problems at once - (Occan's razor says the simplest explanation is the most-likely)
but still

I also suspect that the pressure control sensor port might be debris clogged - causing it to fail to cut in and out when it's supposed-to.

A burst tank bladder will cause the tank to become waterlogged or for other reasons will cause short on-off cycling of the pump but not the other symptoms you cite.

These questions and answers about troubleshooting and fixing a well or water pump that keeps turning on and off rapidly were posted originally

at SHORT CYCLING WATER PUMP - home - be sure to read the procedures and repairs discussed there.

On 2018-10-02 by Nick

Thank you! A photo of my pump with a GE motor is shown here.

On 2018-09-23 4 by DiAnn

Pump kicKS on for about 30 seconds and shuts off and then come back on about 15 minutes later and won't pressure up over 10 pounds we have replaced the pump and tank

On 2018-09-24 by (mod) - pump shuts off for 15 minutes

Di

I generally stay away from guessing Ed problem causes that involve to false at the same time, but this sounds as if there may be a leaky foot valve or check valve or water running somewhere in the building, combined with a inadequate water in your well

On 2018-08-21 by Amanda - Short cycling pump keeps burning up pump switches

We are having a terrible time trying to figure out what is going on with our well pump.

We have gone through 3 to 4 pressure switches put in a new well pump and out pressure switch keeps kicking on and off every 1/2 sec. We run our pump during the day but have to shut it off at night to keep from going through another pressure switch.

The pressure switch we normally use is a 20/40 but even after shutting off the pump and water supply the pressure switch still cuts in and out 1/2sec till we manually stop it. We don't know what else to do or replace. Can you help?

On 2018-08-21 by (mod) -

at the live link

Continue reading at SHORT CYCLING WATER PUMP - home

 

On 2018-07-06 by KenV - Pump failure diagnosis for cistern water system

I have a cistern system that is supplied by delivered, hauled water.

I replaced the pump a couple of months ago with a stronger pump and higher pressure switch and water pressure to the house improved.

2 months later my pump runs twice as long to bring pressure switch back to 50 PSI and cut off.

Water tank capacity is much lower now due to consumption over two months. Could weight of the water decreasing cause less suction side pressure? Any suggestions?

On 2018-07-06 by (mod) -

Ken

I don't think so. Is your pump combined with a pressure tank or are you using a pressure-sensitve pump with no pressure tank ? - as we often do with cistern systems like yours.

I'd look for a damaged pump impeller or debris clogging.

The weight of water in the cistern or its down-pressure on a bottom outlet does decrease as water is used. That's why in many cistern systems we elevate the tank above the building's roof.

But the pump ought to have a capacity well beyond that difference in pressure.

At WATER PRESSURE MEASUREMENT https://inspectapedia.com/water/Water_Pressure_Measure.php we explain the weight or pressure of water in a vertical column such as in a cistern, pipe, or well.

Let's be sure that we have the right type of pump and pump controls, properly set.

On 2018-07-06 by KenV

The pump is brand new. It has a cut in @30 and cutout @50 psi switch built in. I have a WaterWorks pressure tank attached with air bladder set to 28 PSI.

On 2018-07-06 by (mod) -

That data sounds quite reasonable.

But something's odd. Any pump and pressure tank combination ought to be able to get you to 50 psi with water supply from a cistern, completely independent from the water level in the cistern itself, unless the pump is not the right one for the application.

On 2018-07-07 by KenV

I will check my filters and see if those are causing the problem. New pump went from 45 seconds to hit 50 PSI to now taking 4 minutes. It is a Pentair 1HP SNE-L 1 HP 115/230 shallow well pump.

On 2018-07-07 by (mod) - Pentair 1HP SNE-L pump specifications

Ken the specs on the Pentair 1HP SNE-L pump give it a lift capability of 25 ft. As long as your Cistern storing water is above the pump level, lift should not be an issue. That's why it makes sense to look for a blockage somewhere. Do keep me posted.

Specs for the Pentair 1HP SNE-L 1 HP 115/230 shallow well pump shown below

Shallow Well Jet Pump (Suction lift less than 25 ft) with Max Operating Pressure at 67 psi / 154 ft Total Dynamic Head

1 hp motor that can operate on either 115 or 230 volts, with factory set 30/50 Pressure Switch

Self-priming after the priming chamber has been filled with water.

Close-grained cast iron body. Drain port provided for easy winterizing.

Specifically designed for water systems & sprinkling for residential homes, farms and cottages

On 2018-07-13 by KenV

OK DanJoe I replaced my filters and pump cycles for about 10 seconds to bring pressure back to 50psi.

I replaced the filters when I installed the new pump so I didn't think they would clog that quickly. But I am in West Texas where the wind blows all the time and I suppose dirt and dust gets in my tanks since they have an air breather cap on them (although the breather has a screen, primarily to keep mosquitoes out.)

This is our ranch house and ground water is contaminated due to oil well production over the last 50 years.

Too far away from the county water line to get municipal water so Stan the Water man delivers it to us. All is now working and I guess I will have to replace the filters on a more regular interval.

They are installed on the suction side to keep dirt and dust from clogging my pressure switch orifice.

On 2018-07-13 by (mod) -

Ken

I INFER from our discussion that while your water source is an open cistern, your water pressure is delivered by a combination of pump (drawing from the cistern) and a pressure tank (floated on the water line common with the water pump).

On a typical residential pump and pressure tank water system, regardless of where the water originated, if a pump gets from CUT-IN to CUT OUT pressure in just 10 seconds, then the water pressure tank has lost its air charge. That's part of the definition and explanation of short cycling given in the article SHORT CYCLING WATER PUMP.

Silt and debris in the water supply can indeed clog the pressure control switch for a water pump. But that clogging will usually result in the pump's failure to turn on or off when it should in response to use of and a drop in water pressure in the system.

I can't quite figure out how a clogged switch sensor would cause the switch to turn off too fast.

But you can watch for such a weird situation by watching the pressure on the system as water is turned on and off. If pressure on a reliable gauge drops below the cut-in and the switch doesn't cut on when it should, that'd be an indicator of clogging. (or something else like damaged relay parts).

Wind-blown dust could certainly get into an open-top cistern or water storage tank where it might foul water, contaminate it (manure-contaminated dust around cattle, for example).

In contrast (and for other readers), windblown dust would have no easy way to get into a water pressure tank- a pressure tank is not open to the atmosphere.

On 2018-07-13 by KenV

Well maybe a little longer than ten seconds but not the 5-6 minutes it was taking. Timed it and takes 36 seconds.

The holding cisterns are black poly tanks for potable water. I have two; one is 1100 gal, the other 600 gal. I have them T'd into the suction side of my pump with valves to shut off the flow from either one with a backflow in front of the valves.

Checked my pressure tank which is a horizontal Water Worker 20 gal actual (40 gal equivalent) and with the system empty and no pressure in the lines the tank bladder is sitting at 28psi. This is 2 psi below my cut in switch setting.

On 2018-07-13 by (mod) -

36 secs. after 5-6 minutes is an argument for loss of air charge in the tank. The tank pre-charge pressure you cite however is right for a 30 psi cut-in.

On 2018-06-30 by Jenni - lose water pressure if we run it too fast

If I turn on the water at the barn too fast we lose all water pressure at the house. We have to close the main line, reset pressure tank, let it build up pressure than reopen line.

The pressure tank trips its circuit, I think. We can take multiple showers at a time, run washer alliances at same time and or sprinkler, without problem.

Makes no difference if water is not being used at the house. If I turn water on too fast we lose water at the house. Been that way for years.

Pressure Tank is Gould V140 installed in 1988. Ink about well pump. Well is 50 yards from house, across flat ground. Drives me crazy. The water pressure at the house is not as good as it used to be, as well..
Thank you,
Jenni

On 2018-06-30 by (mod) -

Jenni

That's an interesting complaint and one I've not heard before.

I would station someone at the pump and/or pressure control switch to watch what happens when you shut off barn water.

Does the pressure on the gauge continue to fall?

Does the pump refuse to re-start?

If so I suspect

- a sticking check valve at the pump or in the well - replace the valve(s)

- a pump that doesn't respond reliably to changes in water pressure - debris clogging - change the switch

- or of course something else we've yet to discover such as the problem that if your well has limited flow and you pump water out faster than the well's recovery rate, you'll lose some or all water pressure in the system.

Keep us posted. What you find will help others.

On 2018-05-31 by Sean Fagan - pump short cycles when we use water outside at the hose

Well is 165 feet deep according to county records. Well is approximately 100 feet deep (sting and plumb bob so it's approximate at best).

New pressure switch 40/60. Tank drained and aired up to 38 lbs. We have had no problems over the 4 years owning this home until now. The pump, when using water hoses out side, has begun "short cycling" (?).

On a consistent basis it runs for 15 seconds then turns off for 105 seconds. I've metered the wires in, at the well casing, and the demand power stays at 240 until the pressure is satisfied. The pump will continually run for 15 seconds and off for 105 seconds until the switch turns off. We have not noticed any issues with just the in house use.

It's only since the I opened the outside lines this summer. One problem I did see, there is are two wire nuts about 18 inches down inside the well casing.

While metering the voltage and timing the cycles, for a few hours, one of these lines shorted against the case a few times causing a loud pop and tripping the 220 breaker.

I have yet been able to figure out how to get down in there to properly repair them. This has been an incredible system, any advice would be greatly appreciated.

On 2018-05-31 by (mod) -

Sean

When the pump runs at regular intervals for "no reason" (no water is being used in the building) then you would look for a leak somewhere - in the building (eliminate that by turning off water into the building) or in the piping between the building and the bottom of the pipe in the well.

But you've identified a different problem: an unsafe electrical wiring or control serving the pump. You should TURN OFF the power to the system and ask for help from your electrician.

She will perhaps check for damaged pump wiring or a problem in the pump or control itself.

Yes the problem could be at wet twist-on connectors on wiring in the well - DO NOT try fixing that with power on - you are likely to be shocked or killed.

You wouldn't reach into the well to fix such wiring, you'd pull the whole assembly.

 

On 2018-05-18 by Colleen - Our pump runs when no water is being used

A second residence is using my pressure tank. It is going off and on when water in the homes are not being used. Is there a problem

On 2018-05-19 by (mod) -

yes there's a problem. If you use the ARTICLE INDEX at the end of this page you can find out article on

WATER PUMP INTERMITTENT CYCLING

Where you will find the diagnostic procedure for the case you need.

 

On 2017-12-30 by Paul

I just replaced my pressure switch in my crawl space. It turns on and off rapidly and then stops until I reset it

On 2017-12-30 by (mod) - pump turns on and off rapidly and then stops until I reset it

Paul,

I suspect your pump is short-cycling until it overheats and is turned off completely by a thermal protection switch in the pump motor.

See the diagnosis and repair steps at SHORT CYCLING WATER PUMP - and let me know what questions remain

On 2017-11-30 by Sabrina - if my pump cycles 6 times when the toilet is flushed, is the pump failing?

My pump kicks up and down 6 or more times to fill my commode. Is my pump going bad?

On 2017-01-05 by Kate - short cycling pump when the toilet tank fills

I believe that I have a short cycling issue but it only seems evident when the toilet tank is filling... I have had the kids run the tub and the kitchen sink and don't get tge same 'on/off' repeat that happens after flushing I just counted 7 cycles for one flush?

On 2017-11-30 by (mod) -

Sabrina,

I don't suspect a bad pump - at least not at the outset, from the description you give. More likely the short cycling is because by one of the problems discussed in the

article SHORT CYCLING WATER PUMP.

On 2017-01-05 by (mod) -

Kate: Very interesting, and I agree a bit unusual. In a normal well pump short cycling problem case, the faster you run the water the shorter it will be the pump on off-cycle period.

Therefore I would look for something else. After all your toilet tank fill rate is surely much less than the flow rate when someone is running water into a bathtub.

Perhaps there is a partly clogged water filter that is causing short cycling when the flow rate is slow.

Another possibility is simply that you are noticing the short cycle rate at the end of a pump on cycle. So check again to be sure that if you run water at other fixtures the pump never short Cycles.

On 2017-08-19 by Johnny Chapman - pump stops for 45 xeconds, then continues

I put a new pressure switch on and new tank today and water pumps good and strong for 3 to 5 min then stops for 45 seconds then nacj on strong then off I need help

On 2017-08-19 by (mod) -

Johnny

Watch the pressure gauge: the pump should turn on when pressure drops below the CUT IN - typically 20 or 30 psi.

If it is not turning on at that point and pressure drops further, then even though there's a new gauge there may be a blockage or clog that prevents it from properly sensing the water pressure - such as a debris clog in the pressure tube that conducts water pressure to the switch bottom.

OR

You are pumping water faster than the well's in-flow rate, causing the pump to run out of water, and it's being shut off by a pump protection devicve.

On 2017-03-24 by Nina M. - The water pump cuts off wayt below the CUT OUT pressure that we set

We just replaced an older 20 gallon water tank with a 32 gallon water tank in a home we just purchased.

We are still using the jet pump (shallow well) and pressure switch (Square D single post switch located at pump).

At the current adjustment, the pump kicks on at 28 psi and we deflated the empty tank to 26 psi.

The issue is that the pump kicks off at 35 psi (not 48 like its supposed to), and we feel like the tank is not at its full capacity.

On 2017-03-24 by (mod) -

Nina

Searching (in the search box just above) InspecApedia for "adjust pressure control switch" finds WATER PRESSURE CONTROL SWITCH ADJUSTMENTS at

Please take a look at that procedure and let me know how that works for you

If proper switch adjustment doesn't fix this pump cut-out problem we'll look further at different problems like pumping water out of the well faster than its recovery rate.

On 2018-10-16 by Jessica - when it rains our pump doesn't seem to work right

We keep having a problem with our pump kick9ng on and off. Sometimes we can go weeks without and issue.

Normally when we lose water pressure, we have to go prime the pump by holding the pressure switch half way between on and off until the pump kicks on by itself. Sometimes we have no water at all.

I have noticed lately we seem to have to go down to the wellhouse and prime the pump more often when it is raining. Is it possible that the rain is affecting the pressure switch?

We just replace the pump and the pressure switch last year. Any ideas? Cause I am tired of not having water.

On 2018-10-18 by (mod) - sometimes we lose prime, pump kicks on and off

interesting question.

I would fix the problem causing loss of prime and replace the pump switch.

see PUMP PRIME, REPEATED LOSS

On 2017-05-03 by Tammie Moore - can water softener regeneration affect pump short-cycling?

My well pump started short cycling several weeks ago at the same time my water conditioner started regenerating much more often. Could these two issues be connected?

On 2017-05-06 by (mod) - yes

Tammie,

I suspect that there may be one or several problems going on producing the symptoms that you described. Short cycling of the pump, that is pump turning on and off too frequently, occurs when the water pressure tank has lost its air charge - we call this a waterlogged pressure tank.

you can use the search box just above to search this website for

WATER TANK AIR, HOW TO ADD

If your water softener is regenerating very frequently, and if no one has adjusted its controls, then it's possible that your building has a water leak somewhere that you haven't noticed and you are actually consuming more water.

If your water softener is one of the more sophisticated models that monitors water usage that would cause it to go through a regeneration cycle more often.

The relation between these two events might be that an increase in water usage would speed the loss of air charge from my older traditional steel water pressure tank.

Another explanation is that when we significantly increase water usage at a building AND if the water pressure tank isn't one that keeps its water and air charge separated by a bladder, the air charge may be lost (absorbed into the water) and the pump will start short-cycling.

On 2016-09-13 by Tracey - water pump short cycles only when we run hot water

Hi, Our pressure pump cycles only when the hot water tap is on. Cold water is fine. I can see your tips for blocked pipes and valves not fully turned on. Any other reasons why only hot water would be affected? We have a storage tank for the hot water. Thanks, Tracey

On 2016-09-13 by (mod) -

Tracey

Like the Poughkeepsie police told Anna M when she complained that the trains running along the Hudson River were blowing their horns too loud, "Well that's one I've never heard before!"

I can but guess that when you are running hot water, maybe with cold on too, or not, that water is running at a faster GPM flow rate and the pump has to cycle more often.

Question: Drastic water pump short cycling every 3-4 seconds, sometimes pump won't come on at all, loss of house water pressure

Mark said: Ok so I have a few problems here. First off my pump is short cycling drastically as in I flush my toilet and within 3-4 seconds I hear the pump kick on. Second, when it kicks on it only stays on for a few seconds before turning off then it only stays off for a couple more seconds before turning back on.

And recently about once a day or once every couple days the pump wont come on at all and I have to go down and tap the pressure control switch housing for it to come on.

By the time I realize that, we have pretty much lost all pressure in the house due to normal use.

I haven't quite nailed down any tying reasons or times when this happens like my wife doing laundry or something along those lines. When the pump is working we have plenty of pressure, almost too much (water sprays out hard and makes a mess when doing dishes - "lol").

I have looked through this site and have found a bunch of useful information but am overwhelmed and don't have a clue where to start. Any guidance in this matter would be greatly appreciated. - Mark

(Jan 27, 2013) Hunter said: We have a cistern filled by city water and a submersible pump which pumps to a bladder tank, which supplies the house with pressured water. The water flow from faucets has began to pulse so inspected the pump setup outside and observed the pump shorty cycling.

I purchased and installed a new pressure switch thinking it would be a cheap,easy repair, but afterwards, the pump continued to switch on and off, every second. Does this sound like something is clogged?

(Apr 2, 2014) firstclasslimo said: My pump keeps cycling every 1/2 second for about 10 to 15 pulses( on/off/on/off etc.)when it reaches its cut out set at 58lbs psi.with a differential set at aprox. 63 to 65 psi. I can't find a happy medium to shut this thing off.

When it does shut off, pressure is stable with no loss,that is IF all faucets are closed: but if shower or faucet is running;the pump won't shut off.

I have a new pressure tank with bladder, new pressure switch, new pressure gauge(0/100 range).What do I do? Not sure if I have any valves like a check valve or foot valve etc.installed.

Should I ? This is not a new system it used to work fine then started acting up,so I replaced pressure switch as contacts were carboned bad. Didn't fix. Now I can't get thing set right.

Reply: Your pump is rapidly short-cycling and may be overheating, this can lead to a submersible pump motor going off entirely then back on under control of a built-in thermal overload switch

Mark and Hunter:

You are describing a classic well pump rapid short cycling problem. Eventually that condition can actually damage the well pump, resulting in less water pressure and flow than previously.

You should be able to obtain satisfactory water pressure with the factory settings of your pressure control switch, typically 20/40 or 30/50 cut-in/cut-out.

Mark I suspect that the reason you sometimes lose all water pressure under these conditions is that the rapid on-off cycling of the water pump is contributing to an overheating pump motor. Many electric motors include an internal thermal overload switch. When the motor is too hot, the switch turns off the motor.

Later when the motor cools down on its own, the thermal reset switch resets and the pump will run again.

The rapid on-off short cycling well pump may also have led to burning on the contacts of the pressure control switch. That's why sometimes you have to tap the switch to get the pump to run. There could be other pressure control switch problems such as clogging of its pressure sensor due to debris in the water line.

• Causes of pump short cycling are at WATER PUMP SHORT CYCLING CAUSES.
• Procedures for replacing lost air in the water pressure tank (a common cause of short cycling pumps) are at WATER TANK AIR, HOW TO ADD
• Procedures for adjusting or repairing a bad water pressure control switch are at WATER PUMP PRESSURE CONTROL SWITC

...

Continue reading at SHORT CYCLING WATER PUMP - topic home, the home page for this water pump topic, or select a topic from the closely-related articles below, or see the complete ARTICLE INDEX.

Or see these

Recommended Articles

• WATER PUMP SHORT CYCLING - home
  • WATER PUMP PRESSURE CONTROL SWITCH CHATTER
  • WATER PUMP SHORT CYCLING CAUSES
  • WATER PUMP SHORT CYCLING DIAGNOSIS TABLE
  • WATER PUMP SHORT CYCLING - PIPE LEAK
  • WATER PUMP SHORT CYCLE STOP VALVE

Suggested citation for this web page

WATER PUMP SHORT CYCLING FAQs-5 at InspectApedia.com - online encyclopedia of building & environmental inspection, testing, diagnosis, repair, & problem prevention advice.

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

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