Goulds water pump excessive cycling

[Eric Scantlebury]

Hello All,

I have an issue with my goulds well pump recently cycling on and off in an excessive mannor. By excessive I mean the pump will kick on and off several times a minute while water is being used in the house.

The specifics: I have a 1/2 horse power goulds Jet water pump model J5S installed in my basement that is pulling water from a point in my front yard (no well). This pump feeds a Wellmate WM-6 bladder water tank. The pump is around 4 years old and the tank is around 10.

I think the pump is working fine as when an upstream valve is turned on the preasure gauge on the pump falls like a rock from 60lbs to 40lbs kicking the pump on which makes the preasure fly like a rocket back up to 60lbs kicking the pump back off. This then repeats over and over. The manual for the pump indicates 4 things may cause this. 1 - a bad foot valve (I don't think this is the case as the pump holds preasure when not in use). 2 - the pump is more than 5 feet from the water tank (it is 2 feet away). 3 - there is a valve between the pump and water tank causing resistance (there is no valve placed there) and 4 - a waterlogged water tank.

Ok - I also have had the service panel in my house upgraded one week ago so power was off to the whole house for about 5 hours last wednessday. Yesterday I ran a new line to the pump so had power off to that for an hour. I don't think that rewiring the pump could have caused this but I throw it out there as a coincidental thing anyway.

Anyone have any ideas as to what may be happening? I'm suspecting something with the tank but I'm open to expert opinions.

TIA

[Don Young]

You already have the most likely cause: #4 - waterlogged tank.

Don Young

[Eric Scantlebury]

But the tank has a bladder. How do I determain if it is "waterlogged" which should be impossible under normal circumstances?

Eric

[RBM]

I'm suspecting the tank too. Sounds waterlogged

[EXT]

Air leaked out of tank: bad fill valve. OR Leak in bladder: water filled the air half of the tank behind the bladder.

[Eric Scantlebury]

So how does one test for this? The tank, when the pump has cycled to it's normal 60 lbs high point, has 36 lbs of pressure at the air valve. I've read a little about this and apparently it should read 4 lbs less than the low kick in win no water. Does the 36 lbs translate to anything non drained and fully preasurized?

[Eric Scantlebury]

Right, I sort of agree just trying to figure out how to test for that with a tank that has a bladder. Ideas?

[dpb]

Drain the tank entirely. If it's waterlogged, you'll be able to tell it from the weight left in the tank from the water and the air pressure will still be higher than it should be which normally would be 2-lb below the cut in pressure.

If the leak isn't too bad, reset to the proper pressure and it will give you a fair period of time before it gets excessively waterlogged again, but a new tank is in your future sooner than later.

If you can do w/o water for a period, you can try to pressurized the air side by a few pounds over the setpoint and see if that will force a small amount of the water back across the barrier. This works better for diaphragms than bladders, but sometimes can help. Needs a long time for it to manage to make any real difference, however, unless the hole is quite sizable, in which case the time of satisfactory operation will be measured in days at best rather than weeks before the exercise must be repeated.

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[Harry K]

You are checking your pre-charge at the wrong time. Correct is to totally drain the tank, and set the pre-charge to 2 psi below the cut in pressure. Then turn pump back on.

I find it more than passing strange that the guage is reading 60 psi but checking at the air valve only shows 36 psi. There is something more than odd there, I would have said impossible prior to your post. There should be no difference between the guage and air valve...well, other than instrument vagaries.

Cause of pump short cycling can, in almost all cases, be traced to the pre-charge (incorrect), a malfunctioning pressure switch (not all that common), a water logged tank caused by a blown bladder or diaphragm.

If it is the bladder or diaphragm, I believe it was dpb who gave a possible short-term fix for it but tank replacement is the proper cure.

Harry K

[Paul Franklin]

You said in your original post that when you run water after the pump has cycled the pressure drops like a stone to 40 lbs. This isn't right, the pressure should drop gradually as you run water; that's what the tank is for. This combined with your measurement above makes me think your tank has lost its air charge, or most of it. If the bladder had failed, you probably would have had water leak out the air valve when you checked the pressure. But if you just put a gauge on there you might not have noticed. take the cap off the valve, and depress the stem with a small screwdriver and see if any water comes out at all. If so, replace the tank. If not, try draining the tank and with the water drain valve still open, recharge the tank to 2lbs less than cut-in pressure. If this works, great, but it probably won't last, since whatever caused the air to leak out will probably happen again.

Another (remote) possibility is that you've got sediment and debris totally blocking the tank inlet so that it is effectively out of the picture. If you don't see the air pressure change while the pump is cycling on and off, I would suspect this as the cause.

HTH,

Paul F.

[David L. Martel]

Eric,

The bladder will slowly "leak" air even when everything is fine. Haven't you noticed that tires and balloons go flat after a while? Get an air gauge and check the bladder. With the tank empty of water the air pressure should be a few psi below the cut-on pressure

Dave M.

["Blattus Slaf]

I've seen tires still up on vehicles in the woods for 20 to 40 years. Air should not leak unless there IS a leak.

["Blattus Slaf]

There is or should be an air stem on the top of your tank. put some air into it. Liquid does not compress, air does.

[Bubba]

Usually, but not always, if the bladder is leaking you will get water coming out of the precharge port when you push on it. Also, if you press on that port to test it and you get no water but some really foul smelling odor, you can pretty much consider the tank toast. Its hard to describe the smell. It is just a really foul nasty smelling rot. If all that doesnt help, unscrew the tank from the boiler and visually check it and test it for water and/or air. If there is no valve to shut off the system to keep water from coming out, then drain the system first. When you reinstall the tank, make sure you add a shut off valve for the next time. Bubba

[dpb]

Bubba wrote: ...

???

This is a potable water system pressure tank, not a heating system...

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[Stormin Mormon]

Would it make too much sense, for those expansion tanks to have a valve stem on top of the tank? When your tank is waterlogged, get your air compressor, and pump some air into the top of the tank.

[Eric Scantlebury]

Correct. I am talking about my incomming potable not my hot water tank.

[timbirr]

SNIP

Hey, folks I am guessing an EASY reason for this. He had the power turned off quite a bit so he says. If, like at my house, the kids and wife ignore me when I say DON'T USE WATER when the power is off, that's what happened....Drained the tank, no input from the pump.....yahda yahda yahda.....

Solution, turn off the main water cut-off when you cut the power. Wife and kids ain't happy, but saves me hassling with the tank later.....

[Eric Scantlebury]

For anyone who is interested and just for the postarity of the post I figure I'd update what I've done.

Ok, I drained the wellmate - seemed like more than 20 gallons came out, but not much more. I then presurized the tank to 45lbs of air and left it for an hour.

When I came back I still had "close" to 45lbs but not quite. I think the bladder has a very small leak and over the last 4 years or so has caused the "waterlog".

I put 38 lbs of pressure in the bladder (I let some air out) and put power on the pump. Now everything seems to work "normal". My short cycling has gone away - though since it has I guess I have "decided" I need a new water tank in my future.

Thanks all for the suggestions - It was a great help.

Eric