Cycling of Well Pump

wsmm

Member
I have about a 13 gallon pressure tank on my well pump. The tank is about 30 years old. It seems from time to time the pump cycles on, runs for awhile and then turns off even if water is not being used. It's not that frequent, amybe once or twice in an hour or two. Maybe even longer. Is my pressure tank going bad?
Thanks,
Bill
 
Make sure you don't have a leak anywhere. Sometimes they can be hard to find. If that's not the case it sounds like your check valve is bad and letting the water go back down the well. It shouldn't come on ever if you're not using water.
 
had something similar happen to me -- as it turned out it was the pitless(?) adapter - bad O ring - letting the pressurized line spray inside the well casing. That caused a loss of pressure, and pump cycling. Agree with the davpal about that possibility too. And I've replaced the bladder tank, and two submersible well pumps here since 1987.
 
Probably not the pressure tank, unless you can see a leak. I don't know what kind of well setup you have but it could be the pitless or the check valve. If you can open the top of the well and listen you might be able to hear it.
 
If there is a valve after the tank, close it.

Then open a down stream faucet to verify the valve did seal closed.

Watch the pressure in the tank, or monitor the well, see if it cycles on. If it holds pressure, and doesn't cycle, the leak is somewhere after the valve. If it continues to cycle with the valve closed, there is a leak somewhere down the well or the check valve.
 
Your tank could be water logged and if so you need to add some air to the tank. Water does not compress so if it does not have enough air in the tank it will do just what your having a problem with
 
I would check pressure in tank also

If not, is typically the foot valve (known commonly as the pitless adapter)
 
1. Is this a simple water and air tank, or does it have a bladder in it? Either way get the right amount of air or the right amount of pressure in it. ( If a simple tank just adding air is the fix 95% of the time. The air absorbs into the water over time and the tank gets waterlogged.) it's possible the bladder in a bladder tank ruptured, but that often has other symptoms. I'm guessing you told us you have a bladder pressure tank, but have to ask.....

2. Do you have a leak? Others covered how to check. Either the back flow/check/foot valve from the hole to the tank or a pipe or valve anywhere along the line could be leaking.

2.b toilet leak. That flap in the tank can leak so lightly you never notice it. But it pulls away enough water your pump runs every few hours. It's hard to believe unless you put food coloring in the tank and see what happens to the bowl in an hour.......

3. If your pressure switch is on a little skinny pipe, I've had them plug up with sediment/minerals and the pressure switch gets erratic pressures as that little tiny pipe is plugged.

4. The pressure switch can get flakey on you over time.

Paul
 
Hello wsmm,

If there are no leaks in the house, toilet bowl is a good place to start, then the well piping or the check valve is letting pressure back down into the well. You can shut the main valve to the house to determine which one is at fault. Short cycling though is another issue. Bladder tank 30 years old probably should be replaced. Low Pressure on the bladder will make it short cycle, one minute or less on and off. Bladder pressure should be 2 Lb. less then the cut off pressure.

Guido.
 
My guess, if no water is truly flowing out plumbing somewhere would be the check valve is faulty and you are losing water backwards down the well pipe. A water logged tank won't cause what you're experiencing. A water logged tank will cause the pump to run when water is flowing out through the plumbing, but it won't cause a pump to just start up to replace water that isn't going down...unless its going down. If it's replacing water, it has to either be out through your house plumbing, or back down the well pipe...faulty check valve between the pump and the well pipe isn't closing completely, water back filling the well pipe by either pressure in the tank, or gravity if the tank is water logged...two separate problems.

Mark
 
Look for this guy or one like it. They do go bad...quicker with hard water.

Good luck.

Mark
a238618.jpg
 
When mine get water logged the pump will run for a good while then shut down. It does it that way because water will NOT compress so what little air is in the tank takes a lot longer to compress so a long run time and a short off time
 
Hello Dpendzic,

Bladder pressure shold be 2# less the cut out pressure, not a misprint,

Guido.
 
+1 on a "...pipe or valve...." 35 yrs ago, had the very same thing happen as you describe. I pulled the pump, replaced the foot valve, no change. Replaced the pitless adapter O-rings...nada. The 3rd time that I pulled the pump (getting really tired of doing it by that time), I happened to notice a wet spot on the ground a foot above the pump. A section of pipe had blown out a pinhole and allowed the 60' column of water to slowly drain back into the well. Fixed that and no more cycling...until a year or so later, when the cycling started again. Yep, pulled the pump again...no faults. I ended up finding a 2" long section of the black plastic tubing from wellhead to the house split where the builder/plumber had kinked it & then unkinked it before covering the trench, and the weakened spot failed...which I finally found after tunneling/hand-digging a 4' deep trench underneath our deck.
 
Yep, vertical so the spring loaded valve falls naturally by gravity. Here's a picture of a shallow well in one of my barns. If you visually trace the piping, as it starts down can see the gold colored check valve in the actual well pipe that goes down into the ground. Vertical. With my well I have a "T" below the check valve with a cap so I can open it to drain the pipe (lose prime) and drain the tank for winter. I also stuck a valved gate between the pump and the check valve so if I ever have to change out the check valve, I can close off the tank so as not to empty it. Had I been smart, I would have run another gated pipe parallel to the check valve that bypasses it so if my well pipe ever loses prime, I could open the gate bypassing the check valve and dump the tank into the well to prime it. Oh well, I screwed up.

Mark

Mark
a238628.jpg
 
I have a filter on mine due to sand and iron in the water here and when the filter stops up it will make my pump short cycle.
 
perhaps i used the wrong terminology---its also called the cut on pressure---this is from my operation sheet for the tank

Prior to operation, with the tank, empty of water, the pressure should be 2psi below the cut-on pressure. So, for example, with a 30-50 pressure switch (factory default setting), air pressure in the tank will equal 28psi. If the pressure switch is adjusted to 40-60, the cut-on pressure will be 38psi.
 
Hello dpendzic,

That is not correct. My latest well is a submerged one. IH.P. 25 gallons per minute. With six sprinklers heads and a garden hose full blast the pump cycles on and off. It is a 34 gallon tank. I think the pressure is set about 30 PSI on and 50 or 55 PSI off. Look at the picture and read the label. It came from the factory at 38 PSI not 28. I did not needed to put more air to it, as it has been doing just fine......

Guido.
a238665.jpg
 
(quoted from post at 18:19:28 09/27/16) Hello Dpendzic,

Bladder pressure shold be 2# less the cut out pressure, not a misprint,

Guido.

If turn on pressure is 30 lb. and turn off is 50 lb. and pre-charge is 2 lb. less than 50-2 = 48 , then how is the is the pump ever going to come on because the working pressure will never get below 48 ?

Dusty
 
Hello dpendzicl,


I don't remember the cut in pressure, but it cuts out about 55#. Buf you are right! It is the cut in pressure that determines bladder pressure. I know my tank bladder came with 38# and was originally set to go off at 60#. The tank certainly never had 58#. Again you are right......I stand corected,

Guido.
 

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