View Full Version : Water well pressure unreliable recently, any ideas?
welllady
Sep 23, 2011, 04:06 PM
I've noticed in the past two weeks my water pressure was been continually changing. If I flush the toilet it takes a while to fill up. But then at times my pressure is where it should be. I could do a load of wash, and have the dish washer on with no problem.
One evening, I did a load of wash, but the next morning during a shower the water ran out. I checked the pressure on the pressure switch, and it read 20. A few minutes later the water came back, rebuilding the pressure to 50.
Unfortunately, now, the water has stopped again, but this time it's not getting any pressure to come through the faucets. I went out to check the pressure switch, and it was reading zero. I checked the pressure in the water tank, and it read 10psi. I added air pressure to the tank to test if it was my tank (diaphragm tank), it added some air, but the pressure reading will not read past 27psi for some reason.
My pressure switch is 30/50. Not sure what would cause that. I've turned on my faucet a few times today. I get water, but only for a very short time, and only in drips. Not sure what could be the problem.
Is it my pressure switch, my tank or could it be my pump.
I would appreciate any help in the matter.
ballengerb1
Sep 23, 2011, 06:38 PM
This very well could be a failing pressure switch. Open the switch box and wath to seal if you can hear and see the switch kick on when the pressure falls below the set point.
hkstroud
Sep 23, 2011, 09:25 PM
I added air pressure to the tank to test if it was my tank (diaphragm tank), it added some air, but the pressure reading will not read past 27psi for some reason.
How was that pressure measurement taken. That pressure measurement must be taken with a tire pressure gauge at the valve stem where you added air. What you are measuring is the air pressure of the bladder pre-charge. At that time the pressure gauge that is measuring water pressure will read zero if the tank is empty.
If your pump switch is set to come on at 30 lbs. then 27 or 28 lbs. of pre-charge is correct. If you mean that air pressure at the valve stem would not go above 27 lbs. that would indicate a ruptured bladder and that the air charge is escaping either down the well or out a faucet.
If you are saying that you added air to the bladder and could only get the water pressure gauge to go to 27 lbs. that would indicate that you had a small amount of water in the tank and increasing the air in the bladder created addition pressure on that water which promptly disappeared as soon as that water was used.
Other symptoms you describe indicate a faulty pump switch, faulty pump or a failing well.
What type of pump do you have surface or submersible?
Right now I assume a submersible since you did not mention whether the pump was running.
As Bob has advised, remove the switch cover and see if the points of the switch are closed. That would be the first step. The next step, if the points are closed, would be to take a reading of the amperage draw of the pump with an amp probe to determine if the pump is indeed running.
If the pump switch points are not closed the switch itself could be faulty or more likely the piping to the switch is clogged with rust, debris or sand.
First tell us how you got the 27 lb. reading. Remove the switch cover and see if the points are closed.
welllady
Sep 24, 2011, 08:55 AM
Thanks for responding. @ Hkstroud the pressure measurement was taken with a tire pressure gauge at the valve stem where I added air. My thinking was maybe due to it being low in pressure, if adding more pressure it would then give me water. It did not. In reading some things on the internet I concluded it might be best to take that air out down to where it read the first time (10) before replacing the pressure switch. All the wiring is fine, cleaned the area of any debris. There is electricity coming into the pressure switch, but the reading is zero. Sorry but I don't know what you mean by point of switch. If that is the contact that pivots than yes I checked that and when trying it out manually (without the electricity on) it still pivots fine. If it is my tank, would the pressure gauge read zero? Wouldn't it still read some kind of pressure from the pump to the pressure gauge, yet not have any water coming into the house due to a faulty tank? My well is about 80 feet from my house, it is a submersible pump. I guess the only way I can find out if the pump is working is take the concrete top off, and see if I hear it running. If it's working than it's replacing the pressure switch today, and see if that's the problem. Since my tank is self pressurized would I still need to put air in the tank (it's reading 10 now) to get it working or will having a new pressure switch (if that is the problem) kick in the tank to start pressurizing, begin bringing water into the house? Again thanks for your help.
hkstroud
Sep 24, 2011, 12:59 PM
Bladder tanks should be pressurized to 2 lbs below the pump switch setting. That way the pump comes on just before you run out of water.
The pressure gauge only shows the pressure on the water in the tank. It does not show the pressure of the air in the bladder.
To explain let me go back to the older style galvanized tank which is commonly called a pressure tank. It is simply a sealed water tank with no bladder.
If you take a seal tank, no matter what the size, which is empty except for the air in it and begin pumping water into it. When the tank is approximately 1/3 third full of water the air in it will be compressed to approximately 40 lbs. Note that the air is compressed, not the water. You cannot compress water. Note also that you have compressed the air to 2/3 thirds its original volume. When the tank is approximately 2/3 full of water the air will be compressed to to 2/3 its original volume and will have a pressure reading of 60 lb. It is the compressed air that exerts the pressure on the water.
Note also that the usable volume of water in the tank is between the 1/3 mark and the 2/3 mark or approximately 1/3 of the total tank size.
One problem with pressure tanks is that over time, the water in the tank will absorb the air when under pressure. When all of the air is absorbed by the water there is of course no air to be compressed. Your tank is then what is known as "water logged". When your tank is water logged and you open a faucet and use a small amount of water, the pressure will drop dramatically and the pump will come on. When you close the faucet the pressure will shoot up rapidly because you cannot compress water. This is known as short cycling and is very hard on the pump motor. When a tank becomes water logged you must turn off the system, drain the tank and allow it to refill with air.
To solve this problem, the bladder tank was invented. The bladder keeps the air and water masses separate so that the air is not absorbed by the water.
Note that when you went from 1/3 to 2/3 water levels in the pressure tank, you further compressed the air which was already under 40 lbs of pressure to 1/2 half its volume and created 60 lbs of pressure.
So now take the bladder tank. When you add air you are blowing up a balloon in side the tank. When you start pumping water into the tank you are compressing the bladder which has 40 lbs of air pressure. When the tank is approximately 1/2 full of water you will have reduced the air volume in the bladder by 1/2 and created approximately 60 lbs of pressure. That means you get to use 1/2 the tank as opposed to 1/3 as you did with the pressure tank.
So a bladder tank does two things for you. It keeps the water and air separated so that you tank does not become water logged and it allows you to store a larger volume of water between the pump cycles.
Granted this is probably more than you wanted to know about well systems.
I'll repeat something I said in my first post. If you are unable to pressurize the tank more than than 27 lbs as measured with a tire gauge at the valve stem you have a leaking or ruptured bladder. The air is escaping the bladder. The air may find its way down the well pipe or it will come out the first faucet that is opened.
Usually a rupture bladder is determined by pressing the needle of the valve stem. If you get air the bladder assumed to be OK. If you get water the bladder is leaking, you have lost the air pressure and water has entered the bladder. This will not be true in your case because you have recently added air.
The points of the pressure switch are the places where movable and non movable parts come together to make electrical contact. Water pressure from the piping causes these to open and turn off power to the pump. A spring causes them to close and send electrical power to the pump when the water pressure is relieved. The surfaces of these points should be smooth. Over time the making and breaking of the points can cause pitting due to arcing. When that happens they may not make good contact. Rough, pitted points can be made smooth again with sand paper or a small file.
Another thing that can cause a pressure switch to fail is clogging of the pipe or tubing to which it is attached. The water pressure is usually strong enough to cause the switch to open but the spring is not strong to push the water pressure back and allow the switch to close and turn the pump on. The easiest way to tell if you have good contact is to do a voltage check of the wires on the pump side of the switch.
If you have voltage on the pump side wires you must then determine whether the pump is actually running. The easiest way to do that is to remove either the switch or the pressure gauge, turn the breakers on and see if the pump pumps water out the pipe.
If you determine that the pump is running and actually pumping water and yet the problems continue, you will have to determine whether the water level in the well has dropped below the pump level.
Sorry didn't mean to write a book but wanted to pass along as much information as I could.
jlisenbe
Sep 25, 2011, 06:27 PM
Frequently people post on this site about trying to add pressure to the pressure tank to see if that will solve their problem of not having sufficient water. It never does since that doesn't really relate to the purpose of the air in the tank. As HK explains very well above, the air in the tank simply is there to provide a gas which can be compressed to store water under pressure. The deal about being 2# under the cut off point is primarily done to preserve the life of the bladder in the tank, but it's not going to prevent you from getting water.
Your problem has to be the pump either not cutting on or cutting on but with not enough well water to meet your needs. Changing the switch is a relatively cheap and easy first step. If you do it yourself, you buy the switch for about twenty five bucks.
If you can see the switch points are closed (together) on a new switch, then you can reasonably assume the pump is on or at least should be on. In that case, if you are still not getting water, then you would know the problem is in the well.
welllady
Oct 13, 2011, 02:57 PM
Sorry for not getting back to all who have tried to help me out. After trying the simple things, it turned out to be my well pump. I found a really good plumber by accident, while driving to my job. Turned out to be a hard working honest man (they're still out there). I now have water, and all is well at the home front. So thanks again to all who tried to narrow it down for me, it is much appreciated!