Water Pump Short Cycling Diagnostic FAQs

Well pump short cycles on and off even when our water is turned off

The water well turns on and off rapidly even when no water is in use, the pressure gauge slowly drops when we are not running water; what's wrong ? On 2017-04-22 by Margaret

by (mod) re: signs of a leak in well piping or a bad foot valve PLUS a waterlogged water pressure tank

Sounds like you have two things to fix:

1. 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.
   
   See the repair advice at WELL PIPING FOOT VALVES
2. You also have a waterlogged pressure tank - that would cause the short cycling when the pump is running. Without an adequate air charge in the water pressure tank, when the pump turns on it very quickly reaches the CUT-OFF pressure, but as your foot valve is leaking (or there's another leak somewhere), water runs out at the leak point, quickly dropping tank pressure and thus turning the pump on again.
   
   After first turning off the pump and draining pressure from the system, set the water tank air pre-charge pressure to 2 psi below the pump CUT-IN pressure
   
   Detailed diagnosis and repair advice are at WATER PUMP SHORT CYCLING

Pump Short Cycles if I force it on - wrong pre-charge pressure?

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 2017-03-19 by cheri walker

Explanation 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.

In other words, if the tank's air pre-charge pressure is above the cut-in pressure, the pump pressure switch will never turn on the pump.

Now besides that, I suspect that your pressure gauge is not reading the actual water pressure accurately: if the gauge is debris clogged it will be way off in reporting the actual water pressure.

Turn off the electrical power to the pump

Drain all water pressure from your system (open a nearby sink tap)

Set the water tank's air pre-charge to 2 psi below teh pressure switch cut-in pressure. So for a 30/50 pressure switch (CUT-IN / CUT-OUT pressures) set the tank's air charge to 28 psi.

Electrical & Switch Failures vs Short Cycling Water Pump

When I tap the pressure switch it turns off the pump

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 2016-10-23 by Fred

Explanation by (mod)

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.

Can Short Cycling melt the pump motor capacitor?

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

by (mod) re:

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.

Loud Pop noise then pump stopped working: bad pressure tank?

Sorry 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 2015-07-12 by POP

Safety Warning by (mod) re: turn off power to an unsafe well pump: replace failed motor capacitor?

A burst water tank bladder would not normally make the very loud pop sound you heard; more likely a pump motor capacitor exploded or there was another electrical malfunction.

Watch out: 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 but as I said I suspect it's an electrical problem at the pump motor or wiring or pump control switch, possibly a short circuit or a seized pump motor.

Also see POPPING SNAPPING NOISE DIAGNOSIS - Daniel Friedman