Slow drop in well tank pressure


  #1  
Old 05-31-16, 01:37 PM
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Slow drop in well tank pressure

I joined the forums today to look for answers - so far I'm at a loss. I had a leak in our well line fixed last week. The old well tank was going bad too and that was replaced today. I found the cycle on this site earlier and pasted it here so I can highlight my problem (if it is one).

My tank pressure goes up to 60 and the well pump switches off. With no water running anywhere in the house, the tank pressure starts to slowly drop to 40 and then the pump kicks on the raise the pressure back to 60 - but no water has been taken from the well tank. I'm having trouble figuring out what is going on. Shouldn't the tank pressure stay at 60psi until water is called for?

There are no visible leaks. I've read a lot of things the past few days, but am no closer to finding out the problem. Is it possible that water is leaving the tank and going back down the well pipe? We have a 300ft artisian well that overflows because we have great water supply. I was going to time the minutes between the 60 --> 40 psi drop, but haven't done that yet.

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Any and all suggestions are welcome. I did not do any of this work myself - had professionals do it, but it just doesn't see right to me. Thanks for any advice.

Here's the cycle I found - it is exactly what I expect my system to do, with the exception of a pressure drop while no water is being drawn. Our water pressure is always good and doesn't fluctuate either.

1. The system is at rest. The pump is off. The pressure is at the highest value, 50 or 60 is that value depending on what the pressure switch is set for. For purposes of explanation, we will assume that the switch is set to 40/60, so the gauge reads 60 at this point.
2. A tap is opened. Water begins to exit the tank. Pressure begins to go down. You can see the pressure go down by watching the pressure gauge.
3. The pressure passes the midway point. The gauge reads 50.
4. The pressure is now down to 40. The pressure switch clicks and turns the pump on.
5. Now pressure is dependent on the pump. The tank does nothing since it is receiving and sending water at the same time. Depending on how much water is exiting the tank, the pump may start catching up and the pressure will rise such as if a kitchen tap was open, or it may decrease if a large amount is leaving, like a shower or washing machine is being used. Whatever happens though, it is only the pump that supplies any pressure.
6. Tap is turned off. Pump keeps running. Pressure rises.
7. The pressure passes the midway point. The gauge reads 50.
8. Pressure is at 60 and the pressure switch clicks again, turning the pump off. It should not turn on again unless a tap is opened and the pressure drops to 40.
9. The system is at rest. The pump is off. The pressure is at the highest value, 50 or 60 is that value depending on what the pressure switch is set for.

And the cycle repeats.
 
  #2  
Old 05-31-16, 02:31 PM
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Water is leaking somewhere. Possibly through some of the components down at the bottom of the well if this is a submersible pump or a jet pump.

There should be a check valve in the cold water incoming pipe or in the pump itself. This could be worn so as to let water seep the wrong way which can also give you the symptoms you have..
 
  #3  
Old 05-31-16, 03:40 PM
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I agree. There is a leak somewhere. It's possible that you have another leak in the water line from the well. It could be the foot valve (check valve) at the pump. You could have a leak somewhere in the house you have not discovered.

If your house has a crawlspace go underneath and check for leaks. Get some food coloring and put several drops in the tank of your toilets and see if the color appears in the bowl. Also don't forget that things like water softeners and RO filters can use water without your knowledge.

If you can't find any leaks in the house then I'd install a check valve in the line coming in from the well. Put it before the pressure tank and switch. If the pressure drop continues after installing the check valve then there is probably a leak somewhere in the house. If the check valve stops the pressure drop then the leak is somewhere before the check valve.

In general I don't bother fixing a leak in a water line between the well and house. All too often that first leak is just a warning of things to come especially if you have copper or steel pipe and ground settling and rocks can put a strain on black poly. If there is a leak I usually just replace the entire line... but I have a excavator so it's relatively quick and easy.
 
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Old 05-31-16, 05:06 PM
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Shut off the ball valve to the right of the tank (your main water valve) and watch the pressure gauge. If it drops like before, as the others above said, you either still have a leak in the piping, or the check valve at the pump is bad and allowing water to drain back out.

If the pressure doesn't drop when the ball valve is closed you have a leak somewhere in the house.
 
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Old 05-31-16, 05:11 PM
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That looks like there might be a check valve right before the drain - or is that something else?
 
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Old 05-31-16, 05:52 PM
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Thanks

Thanks everyone for the input. The problem is on the well side of things. Turning off the house water does not see the pressure stay stable. You asked if that is a check valve - yes it is. My theory is that when they fixed the pipe in our driveway that the valve was either damaged or wedged slightly open when the dirty water came through while flushing the pipe. The check valve is the original from 1999. I will most likely replace that and hopefully that will do it.
 
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Old 05-31-16, 08:57 PM
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There is supposed to be a footvalve at the pump to stop the water from draining back into the well. Apparently that was no longer holding and that one in the picture was installed.

Definitely try changing it. Also.... the clamp(s) on the well side of the check valve is(are) critical. It could be tight enough to keep water from escaping but it could allow air in when the pump shuts off. Make sure the new ones are tight.
 
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Old 06-01-16, 04:12 AM
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Originally Posted by toller99
". . . There are no visible leaks . . ."
Then where's all that water surrounding the Pressure Tank and Switch originating ?

It looks like a virtual Reflective Pool . . . . and a great place to get yourself electrocuted !

Dry it up; You've been lucky so far . . . . if you're still there !
 
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Old 06-01-16, 11:43 AM
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The water on the basement floor is from all the work and water that was spilled. It dries up - there's no leak in anything there.

They replaced the check valve today and the old one was all clogged with pebbles and grit - so not exactly closing to hold the pressure.

One would think that would have fixed the problem. It appeared to be holding the pressure fine, but I was just down there and the pressure is still slowly dropping with no water being drawn in the house. No need to reply - just posting an update. Am getting frustrated with the lack of answers from the local guys.
 
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Old 06-01-16, 02:19 PM
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hi toller Ė

Iím no expert but something doesnít make sense here. If you break the entire system up into 3 segments, they are:

1) well pump to check valve at tank

2) check valve at tank to ball valve shut-off for house

3) ball valve shut-off for house through all house piping

If the new check valve at the tank is working properly water cannot flow from the house back to segment 1. So a leak(s) in segment 1 will not cause a pressure drop. But there is a pressure drop. So the leak must be in segments 2 or 3.

If the leak is in segment 2 you would see water on the floor but that does not happen. So the leak is not in segment 2.

If the leak is in segment 3 you would not have a pressure drop when you shut the ball valve leading to the house piping. However, you do see the pressure drop when the ball valve is closed so the leak is not in segment 3.

So there is no leak in segments 2, or 3, therefore, there is no leak that would cause a pressure drop. Yet there is a pressure drop. There is something screwy here.

It is very hard to believe a new check valve would leak and also very hard to believe a ball valve would leak.

OK, just thought of something. When you say
They replaced the check valve today
do you mean the one at the tank? Thatís the one I assumed you meant. If they replaced the check valve at the pump, and the check valve at the tank is not working properly, then a leak in the line anywhere from the pump up to the tank would cause the problem.

If they fixed the pipe in the driveway because it was in bad shape and leaking, many times the rest of the pipe is also in very bad shape and will be continually problematic. My old galvanized steel water service pipe was so bad when I picked it up it was breaking all over the place.
 
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Old 06-11-16, 05:02 AM
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It's possible the new check valve isn't sealing 100%. Another place to look for a leak is at the pitless adapter (where the underground pipe enters the well casing). Good luck, Steve
 
 

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