Well pump on-off rapid cycling diagnostic FAQs:

Questions & answers about the cause & cure of a water pump or well pump that kicks on and off too frequently - posted originally at our table of well pump short cycling causes.

This article series explains why a well pump or water pump may be turning on and off rapidly - annoying building occupants and ultimately damaging the pump or its controls.

Well Pump Short Cycling Diagnostic FAQs

These questions & answers were posted originally at WATER PUMP SHORT CYCLING DIAGNOSIS TABLE - topic home.

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,
SHORT CYCLING CAUSES describes the most common causes of this problem.

If you are not sure what "water pump short cycling" means or how it is recognized,
read SHORT CYCLING WATER PUMP.

Intermittent water pump cycling which means that the water pump comes on at intervals for no apparent reason is discussed
at INTERMITTENT WATER PUMP CYCLING

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

Questions & answers about well pump short cycling posted originally at WATER PUMP SHORT CYCLING DIAGNOSIS TABLE

On 2017-05-23 by (mod) re: why is sprinkler system pump cycling rapidly and then running continuously

Tim

I'm not sure but the fact that the pump keeps running suggests that your well is running out of water.

On 2017-05-23 by Tim

I have a 1 1/2 hours Gould pump for my yard sprinkler system. The pumps send to run for a bit. Then the pressure switch starts to rapidly move to the engaged unengaged position. I have turned the system off but the pump continues to run until it is turned off... Can you please point me in the right direction

On 2017-05-22 by (mod) re: why pump runs for no apparent reason

Denise

It sounds as if you are describing what I call INTERMITTENT WATER PUMP CYCLING - when a pump seems to run from time to time for no apparent reason. There is, of course, a reason. Start with that diagnostic article found by using the search box above or go directly to WATER PUMP INTERMITTENT CYCLING

Keep me posted.

On 2017-05-22 1 by Denise

Why is my water tank pump switching on and off. Water level in tank is fine

On 2017-05-16 by (mod) re: how do I fix a short cycling well pump ?

The most common repair is in response to the most-common cause: a waterlogged pressure tank.

To fix that you need to add air to the tank, by draining it for example. If you use the search box just above to fine our article WATER TANK AIR HOW TO ADD you'll see some simple procedures for doing that.

Other causes of short cycling pumps listed in the table in the article above have, in the right column of the table, links to diagnosis and repair articles keyed to each of those short-cycling causes.

On 2017-05-16 by Linda

How do you fix a short cycling pump

On 2017-05-06 15:21:31.690570 by (mod)

Your pressure control switch may not be sensing the drop in water pressure that should cause it to turn on the pump. That may happen due to debris clogging. Try replacing the switch.

On 2017-05-06 14:55:59.201167 by Cheryl

Good pressure then no pressure then turn the water off and back on then the same thing

On 2017-04-26 by (mod)

I'd look through the list of causes of pump rapid on-off cycling in the table above as that's a succinct list of the causes and cures.

On 2017-04-26 by Delia duke

I have a bladder tank and its marginal pump sommerjubel home and it keeps shutting off and on rapidly when it shuts off it slammed shut

On 2017-04-23 by (mod)

Michiel what you describe sounds like the problem addressed by the diagnostic checklist in the article above.

On 2017-04-23 by Michiel

My pump drops slowly pressure from 3 bar to 1 bar, but when a tap is opened in the house it drops to 1 bar switch on and moves quickly to 3 bar. It switches off and fall fast to 1 bar, it switches on again and moves to 3 bar again where it switched off and stayed until it begins to fall slowly again. I believe on the last one the tap has been closed again.

On 2017-04-22 by (mod) re: signs of a leak in well piping or a bad foot valve

Sounds like a leak in well piping or a leaky check valve or perhaps foot valve in the well - that would cause the pump to run when for certain no water is running in the house - combined with a waterlogged pressure tank - that would cause the short cycling.

On 2017-04-22 by Margaret

The water well turns on and off rapidly even when no water is in use, the pressure gauge slowly drops when well is not running?

On 2017-03-19 by (mod) re: wrong air pre charge in pressure tank

Cheri

If the tank pressure is at 32 pre-charge AND if the tank is open to the pump where your pressure gauge is mounted, AND if your pump gauge says 15, somebody's wrong- maybe your pump gauge is clogged or jammed.

Your tank pre-charge should be 2 psi BELOW the pressure switch CUT-IN PRESSURE - so if you're using a 30/50 switch your tank pressure is 4 psi too high.

On 2017-03-19 by cheri walker

I just installed a precharged pressure tank which has 32 lbs. My pressure gauge at the pump says 15 lbs and I cant sync the switch to come on without rapidly switching on and off.

On 2017-01-20 by Pat Brown

Pump comes on and kick out rapidly

On 2016-11-17 by Kerr

I have a pump attached to house and a tank. When filling the tank from the city main water supply system, do I need to switch off the pump

On 2016-10-31 20:33:47.925684 by (mod) re: waterlogged pressure tank indicator

Sounds like the pressure tank is waterlogged, Bruce.

On 2016-10-29 by Bruce

ive got a pressure tank that holds pressure but when water is used my pump cycles a lot to keep up. The tank is a 42 gallon and just started this a week ago. Any thoughts?

On 2016-10-24 by Anonymous

Sounds like a defective pressure control switch. Perhaps the switch has become clogged with silt and debris or its contact points are burned and and failing. I would try replacing the switch.

On 2016-10-23 by Fred

Hello. Woke up one morning and the pump in my aerator was running. Went out and tapped the pressure switch and it stopped. The moment water is run, the pump kicks on but then runs for too long. Once again, tapping the switch makes it stop. Obviously a switch problem, right?

On 2016-08-29 by (mod) re: how to find if a leak is inside or outside the building

Cynthia if you shut off water into the building and pressure continues to fall I suspect a sticking or leaking foot valve or check valve on the well side of the pump and tank.

You may also be getting confusing data from a pressure gauge that's sticking.

On 2016-08-29 by Cynda

My pressure drops suddenly. Holds at 50 then suddenly drops to 30 which is kicking on the pump every 10 minutes or so. Thoughts?

My well pump is kicking on about every 10 minutes. I tried to drain the pressure tank and put air in it but it didn't work. Tank is holding pressure. So I shut off the valve from the pump to the tank and killed the power to see if my pump would loose prime. Left for over an hour and still had prime. I checked the tank pressure again. It went down a little but not much. Is the pressure tank my problem?

On 2016-08-24 16:45:04.150320 by (mod) re: melted pump motor capacitor

A melted capacitor sounds like a shorted wire or failed electric motor; sure a motor might fail due to short-cycling, but a 5 minute draw down isn't what I'd consider short-cycling.

Your pump could also overheat from being run "Dry" without water, or if being supplied with too-low voltage.

I'd ask for help diagnosing those conditions before spending on more equipment.

IN general you'd install a very large water pressure tank to obtain a long draw-down cycle. But once the water usage rate is close to the pump's delivery rate you'll still be taxing the pump with long on-cycles.

On 2016-08-24 by Gerald Whitehurst (whitehurstgm@aol.com)

My system runs on a 28# to 65# cycle. This takes approximately 5 minutes total from draw down back to full charge when watering site. I have replaced the pump and controls within the last six months. The system has now melted the "start" capacitor. I believe that this was due to the "short" cycling of the system. Is there a way to increase the amount of time between cycles so as to give the controls time to "cool off".

On 2016-07-18 by (mod) re: wild pump shut down

If by "wild shutting down" you mean chattering at the pressure control switch, look for burned switch contacts (replace the switch), debris clogging of the switch pressure sensor port (replace the switch), or a clog or blockage at the pump or water outlet (such as a clogging debris filter).

On 2016-07-18 by Anonymous

what causes a irrigation pump to Cycle
pressure switch wild shutting down

On 2015-11-18 by Bonnie Guillen

Our water pump is cycling on and off every few seconds. The water pressure is our shower keeps changing high and low every few seconds as well. This just recently started after having shut the water off to install a new toilet. Any ideas what it could be? Thanks

On 2015-09-01 by (mod) re: well pump comes on and off at odd times

GD

See the diagnostic article
at INTERMITTENT CYCLING WATER PUMPS at https://inspectapedia.com/water/Intermittent_Water_Pump_Cycling.php

On 2015-08-31 by Gdalpha

Well Pump Short Cycle

Need help determining why my sprinkler system well pumps. My pump short cycles under the following conditions:

1. Cycles every 25 minutes with no sprinkler system operating.

2. Cycles every 30 seconds when my sprinkler zone 4 is operating. Sprinkler zone 4 has 2 heads on it.

3. Does not cycle on off, stays on when sprinkler zones 1, 2, and 3 are operating.

Pump on at about 28 PSI. Pump off at 52 psi. Bladder tank with 28 PSI air charged when pump power disconnected and water discharged from piping.

On 2015-07-17 by (mod) re: turn off power to an unsafe well pump: heard popping noise

I'd turn OFF electrical power to the well as it sounds as if there may have been a short circuit or burned-up control. We don't want someone to be killed by electrical shock.

With power off your well or plumbing company can diagnose the problem; from just your email I'm not sure what failed.

Also see POPPING SNAPPING NOISE DIAGNOSIS

On 2015-07-12 by POP

Sry about that it could be the switch popped change it now cant hold water pressure it goes up to 50 psi turns off kicks in at 30 psi then the pressure goes down to zero need help plese

I heard popping noise like a >22 cal going off form my well system after 10 min later I had no water did my pressure tank blew up ? Some one told me

On 2015-07-06 by No Leaks

Not required Thermal expansion safety tanks installed on "open systems" water heaters when the home is on a well / bladder system may cause problems with water hammer bouncing back and forth... definetly lawn sprink zone valves cause hammering from low air x-tanks.

On 2015-06-16 by Anonymous

I just replaced my bladder tank with the same size that was there for years. I added a check valve to the system along with pressure gauge and hooked everything back up and now the pump short cycles about every 2 minutes. I went back and check the air pressure in the bladder tank and reduced it according to manufactures spec. 18 for a 20/40 rating. There are no leaks any where and just have to shut the power to the pump so it does not burn up.

Question: well pump seems to be short cycling while other readers say pump seems to come on for no reason

(Oct 11, 2014) Shawn said:
I have a deep well pump that seems to be short cycling? I have a peroxide system tied into it which brought the problem to my attention. I could hear that system coming on and off. I thought that was my problem and had the company out here to service it and
they noted that the pressure would come up and drop off immediately and then recycle a number of times till it finally held. This happened after they drained some water from the line. They suggested it might be the well pump or check valve. Pump is a submersible.

I have changed the filter in the whole house filter seeing if that would solve the problem. It did not seem too. My next thought is to change the pressure switch. I don't believe that has been changed since house was built in 2006. But because of the nature of my water supply (heavy sulfur content) the pressure tank has been changed out 3 times. The current pressure tank is now a fiberglass and not a metal and was changed out 2 years ago. Do you have any thoughts on this problem?

(Dec 3, 2014) linda said:
If there is a 2 year old well pump and there are no leaks what causes a pump to keep kicking on?

Reply:

An explanation and suggested solutions are in SHORT CYCLING WATER PUMP. Please take a look there and then let me know if questions remain. Thanks.

(Oct 22, 2014) Sherry said:
Thanks so much! Well pump was short cycling and getting hot. I shut off the breaker to cool motor down and googled you. I saw the suggestion for the clogged filter on you problem table.. I had filters so swapped it out and ......it seems to have solved it. Thanks so much for helping solve the problem and saving me the money of a repairman.

Linda: you'll want to see INTERMITTENT CYCLING WATER PUMPS

Question:

(Oct 25, 2014) Tony said:
We have a 4 kw pump for a sprinkler system, we have recently added a new connection to the water supply to fill a tank if we run the sprinklers and fill the tank simultaneously or the sprinklers on their own no problem. If we try to fill the tank without the sprinkler system the pump short cycles

Question: water comes out of the air fill valve on an internal bladder tank

(Nov 6, 2014) Bob said:
Water comes out of air fill valve when pushed does that indicate bladder broken inside?

Reply:

Most likely yes, Bob. You'll need to replace the bladder or the whole tank assembly.

Bob as long as your water pressure tank tank is a typical internal bladder model that stores water in the bladder and air around it.

Question:

3 March 20915 Scott said:

I'm having an issue with my pump pressure switch bouncing at the end of the pump cycle (after reaching the cut-off pressure). It cuts on and the pump works to refill the tank/lines, but once it reaches the cut-off pressure, it stops momentarily, then begins to turn on and off repeatedly and rapidly (I disconnect the power when this happens to avoid further damage to the pump).

I suspected a bad pressure switch and replaced it, but the issue remains. I've drained the pressure tank of water, and adjusted the pressure to the recommended 28PSI. I've also checked the small tube that connects to the switch for debris build up, but it's clean. What's the next step for troubleshooting?

Reply:

Scott

When I see this I check for burned pressure switch contacts - which means replace the switch if that's what you find. If the switch is not burned then check for debris clogging in the mounting tube or switch sensor input port. Last and least likely is a water hammer problem.

Scott said:
Thanks for the info, Dan. I've already replaced the pressure switch and checked the mounting tube and switch sensor input port. Can you describe the water hammer problem?

Scott

Water hammer is discussed at

inspectapedia.com/plumbing/Water_Hammer_Noise.php

sometimes a pump shutting off can cause water hammer in the pipes that might cause a bit of pressure surging - but frankly I suspect the trouble is elsewhere.

CHeck that there's not a nearly-clogged water filter on the system or a blockage into the pressure tank.

Double check wiring throughout to be sure there's no loose connection.

Scott said:
Yes, I don't think I'm seeing any of the other symptoms of water hammer, so most likely another issue. I do suspect there might be a blockage into the pressure tank... is that common? When the problem first occurred a few days ago, I was able to leave the pump unplugged and had enough water and pressure to take a quick shower.

Now, the water is running out much faster. When I rock the pressure tank, it doesn't seem as full as it was a few days ago, even after running the pump until it reaches the cut off pressure. I had someone else looking at it, and they thought the problem might be a bad check valve between the aerator tank and the pump (water from the aerator tank is drawn to the pump and then sent to the pressure tank and on to the house plumbing).

Which direction should the check valve be preventing the water from flowing? It should stop water from flowing back into the aerator tank, correct? There is also another check valve on the line from the pump to the pressure tank. The person I had looking at it said that it was unnecessary and recommended removing it.

...

Continue reading at WATER PUMP SHORT CYCLING DIAGNOSIS TABLE 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

WELL PUMP SHORT CYCLE DIAGNOSIS 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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