Low / Variable Well Water Pressure

Reply

  #1  
Old 02-10-18, 05:18 PM
Member
Thread Starter
Join Date: Aug 2006
Location: Columbus, OH
Posts: 149
Low / Variable Well Water Pressure

Hello, I just moved into this house a little over a year ago. Our previous house had city water, this has a well.

Our main issue is low water pressure. Actually, it does occasionally have good pressure, just not often. I need to do a test where I check to see at what pressure the pump kicks on and off, but I have seen pressures as low as 10-12 PSI and as high as 50 on the gauge at the base of the pressure tank. The label on the pressure tank (Wellmate) says it should have been pressurized at 40 PSI from the factory, but I have no idea how old it is.

My thinking is that I need to shut off the pump and drain the pressure tank to verify that it is pressurized properly and then set the kick on / kick off pressures.

I'm curious about a couple of things.

1 - What do I need to look out for when turning the pump off & draining the pressure tank? The line from the well is higher on the wall than the tank so I'm concerned about draining all that line too and then getting the pump restarted again once I set the pressure tank.

2 - Why would the kick on pressure be set so low? From what I've read it's typically 20 PSI between kick on and kick off. Mine seems to be more like 40. Is there any issue that they may have been trying to work around by setting it that far apart?

Thanks!
 
Sponsored Links
  #2  
Old 02-11-18, 04:36 AM
Group Moderator
Join Date: Mar 2003
Location: NC, USA
Posts: 17,597
1. What type pump do you have? If you have a submersible then you don't need to do anything. Just turn off power to the well and open a faucet until the flow of water stops. When it's time to re-start the pump just turn the power back on.

2. Pressure switches are adjustable. Maybe someone who didn't know what they were doing adjusted the pressure down. It's also possible that the switch is set higher but the pipe nipple connecting it to the water system is clogged.
 
  #3  
Old 02-11-18, 08:52 AM
Member
Join Date: Dec 2006
Location: Canada
Posts: 526
You need to figure out what your true cut in and cut out pressures are. I don't think there are any pressure switches with a 10 psi cut in and a 50psi cut out, so figure out that issue and get some proper readings. Once you know that, then you need to drain the pressure tank and verify what air pressure is currently in there. The fact that it might have been set at 40psi at the factory does not confirm that it is the correct pressure for you. The air pressure in the tank needs to be below the cut in pressure of your pump's pressure switch. 2 or 3 psi below cut in is optimum.

If the air pressure in the tank is in between your cut in and cut out you will have problems, some of which like you are seeing. For example, If the air pressure in the tank was at 40psi and your pump never starts up until it is well below that, then you should be able to see that the air pressure will be pushing ALL of the water out of your pressure tank. A pressure tank cannot exert pressure on water that is not in the tank. So you will get a drop in water pressure when this event happens. In order for a pressure tank to work there will always be some water left in the tank when the pump switches on again, to refill the tank.

As for draining the tank. Turn off your pump. Find a tap in the house that is hopefully below the output pipe of your pressure tank and open it up until it stops flowing. Keep that tap open. Now measure the air pressure. If you can't get any reading at all then it means your tank's diaphragm is ruptured and the tank needs to be replaced. If you do get a reading, if it is higher then the cut in pressure of your switch, let air out until it is 2 or 3psi below the cut in pressure. Add air if it is the reverse.
 
  #4  
Old 02-11-18, 10:46 AM
Member
Thread Starter
Join Date: Aug 2006
Location: Columbus, OH
Posts: 149
Originally Posted by Pilot Dane View Post
1. What type pump do you have? If you have a submersible then you don't need to do anything. Just turn off power to the well and open a faucet until the flow of water stops. When it's time to re-start the pump just turn the power back on.
I don't know, frankly. The well is in the front yard (pressure tank & softener are in the basement). I have a pipe coming out of the ground with a cap on it just outside the front of the house which I assume is the well. I assume the pump is down in there, because where else would it be? The pipe going into the pressure tank comes from that corner of the house. Does that tell you what kind of pump I have?

Originally Posted by Pilot Dane View Post
2. Pressure switches are adjustable. Maybe someone who didn't know what they were doing adjusted the pressure down. It's also possible that the switch is set higher but the pipe nipple connecting it to the water system is clogged.
I'm assuming the switch got adjusted, but what I can't figure out is why? How would I check if the pipe nipple is clogged? Where is that?
 
  #5  
Old 02-11-18, 10:57 AM
Member
Thread Starter
Join Date: Aug 2006
Location: Columbus, OH
Posts: 149
Originally Posted by OptsyEagle View Post
You need to figure out what your true cut in and cut out pressures are. I don't think there are any pressure switches with a 10 psi cut in and a 50psi cut out, so figure out that issue and get some proper readings. Once you know that, then you need to drain the pressure tank and verify what air pressure is currently in there. The fact that it might have been set at 40psi at the factory does not confirm that it is the correct pressure for you. The air pressure in the tank needs to be below the cut in pressure of your pump's pressure switch. 2 or 3 psi below cut in is optimum.

If the air pressure in the tank is in between your cut in and cut out you will have problems, some of which like you are seeing. For example, If the air pressure in the tank was at 40psi and your pump never starts up until it is well below that, then you should be able to see that the air pressure will be pushing ALL of the water out of your pressure tank. A pressure tank cannot exert pressure on water that is not in the tank. So you will get a drop in water pressure when this event happens. In order for a pressure tank to work there will always be some water left in the tank when the pump switches on again, to refill the tank.

As for draining the tank. Turn off your pump. Find a tap in the house that is hopefully below the output pipe of your pressure tank and open it up until it stops flowing. Keep that tap open. Now measure the air pressure. If you can't get any reading at all then it means your tank's diaphragm is ruptured and the tank needs to be replaced. If you do get a reading, if it is higher then the cut in pressure of your switch, let air out until it is 2 or 3psi below the cut in pressure. Add air if it is the reverse.
Makes sense, I'll get some real readings and report back.
 
  #6  
Old 02-11-18, 12:01 PM
Member
Thread Starter
Join Date: Aug 2006
Location: Columbus, OH
Posts: 149
OK, cut in was about 11 PSI, cut off about 53 PSI.

However, it didn't maintain the 53. After a few minutes it had dropped below 50 PSI and seemed to be still dropping. It was hard to tell as it drops so slowly. Could that mean a leak somewhere or a bad check valve?

It did take about 1:18 seconds between tuning the faucet off and reaching 53 PSI.

Is my next step to verify my tank pressure?
 
  #7  
Old 02-11-18, 12:22 PM
Group Moderator
Join Date: Mar 2003
Location: NC, USA
Posts: 17,597
If you can't see a pump anywhere and have only one pipe coming from the well you likely have a submersible pump. That means you don't have to worry about priming.

11 pounds is a very low cut in (turn on) pressure. Most switches will not even adjust that low. I suspect that the pipe nipple or orifice into the pressure switch may be clogged. You can remove the switch and nipple and look to see that they are clear. But, since you are having problems I would get a new switch and pipe nipple so you only have to take things apart once.

The pressure dropping is a concern. First. Make sure nothing in the house is using water. Check for RO water filters, leaking toilets, ice makes... When no water is being used the pressure should hold and not drop. The dropping pressure means water is getting out somewhere. It could be a leaking toilet, leaking check valve at the pump or a leaking pipe. Start with easy stuff first. Quite often it's a toilet or RO water filter.

First though I would address the cut in pressure. I would get the system working in a range from 30-50 or 40-60 psi first so you can have a decent shower. Then I'd start investigating why the pressure is dropping when the pump turns off.
 
  #8  
Old 02-12-18, 07:32 AM
Member
Join Date: Dec 2006
Location: Canada
Posts: 526
There is also a possibility that your pressure gauge is malfunctioning. Usually a malfunction there is constant so most likely even if the gauge is faulty, you probably still have a leak somewhere, when you see the numbers declining when you are not using any water.

If you want to see if the water pressure gauge is giving you a relatively accurate reading you can do so by measuring the pressure from your pressure tanks air schrader valve with an air pressure gauge. With no one using the water, look at the water pressure gauge. Now measure the air pressure on your pressure tank. They will never be exactly the same because you will have some elevation differences and pipe bends and no two pressure gauges are ever exactly the same but the numbers should be within a few PSI of each other. If they are not, I would change out the water pressure gauge as well. That is a very important device in maintaining a properly working home water system, as you have noticed.

If water comes out of the schrader valve, when you take this measurement, it is also an indication of a breached diaphragm inside your pressure tank and again, the tank would need replacement.

A note : When you measure the air pressure when the pressure tank has pressurized water in it, you are actually measuring the water pressure, not the air pressure. That is why you were instructed to empty the tank, to get an accurate measurement of air pressure. I just wanted to add that point, to avoid any confusion.
 
  #9  
Old 02-12-18, 06:29 PM
Member
Thread Starter
Join Date: Aug 2006
Location: Columbus, OH
Posts: 149
I did check the tank pressure at one point and found that it was the same as what the gauge read, which I believe was about 15 PSI at the time.

However, the fact that it read that low means that it likely isn't pressurized properly, right?

I'm going to order a new switch and pipe nipple and replace both this weekend. While the tank is drained (and before taking anything apart), I'll make sure the tank is properly pressurized.
 
  #10  
Old 02-13-18, 09:19 AM
Member
Join Date: Dec 2006
Location: Canada
Posts: 526
No, it just means that your water pressure gauge is working properly. The air pressure will equal the water pressure when the pressure tank has pressurized water in it. So your reading does not tell you much about the condition of the tank. The fact that water did not come squirting out the schrader valve indicates that your pressure tank is still in tack. Until you drain it and measure the air pressure you will not know if it is pressurized correctly with air.
 
  #11  
Old 02-13-18, 10:05 AM
Group Moderator
Join Date: Mar 2003
Location: NC, USA
Posts: 17,597
The pressure tank does not make water pressure. It is only there to minimize the on/off cycling of the pump. Focus on it if you start noticing odd pressure fluctuations.

Since you mentioned that your system can get up to 50 psi that is a good sign that your pump is good and capable of developing that much pressure. That leaves the pressure switch which is responsible for turning the pump on and off.

You will need to make sure you have an accurate and working water pressure gauge on the system and an accurate air pressure gauge. The air in the pressure tank should be 2-3 psi less than the pump cut in/turn on pressure. The exact pressures are not important as long as the air is 2-3 psi less then the pump's cut in pressure. New pressure switches are close but not always 100% dead on so don't assume that your new switch will turn on the pump at exactly 20 or 30 psi.
 
  #12  
Old 02-13-18, 01:01 PM
Member
Join Date: Dec 2006
Location: Canada
Posts: 526
Just so that you understand better how your water system works. As Pilot Dane has suggested, the water pressure is created by the pump. The pump pressurizes the pressure tank. You may or may not know that liquids do not compress, but gases compress very well. So to make your water system work well, you put air, which is a gas, into the pressure tank. When your pump pushes water into that pressure tank, the air inside it compresses. When the pump turns off and no other taps are open the air and the water in the tank will always be at the same pressure. If air was at a higher pressure it would push out the water and if the water was at a higher pressure it would push in the air. So, as I said before, when pressurized water is in your pressure tank, if you read the value of the air pressure, you are actually measuring the water pressure. If you want to know the actual air pressure in the tank you MUST remove the pressurized water.

Now when you open a tap, that compressed air now pushes the water out of the tank to provide you with the water you need. The pump is not required at this time. As the tank pushes our the water, the compressed air expands in the tank, because you now have less water, and therefore that pressure reduces. The same air in a larger volume will equal a lower pressure. The law of physics says that the pressure that a gas exhibits is inversely proportional to its volume. So again, as the volume for air increases (as water leaves the tank) the pressure the air exhibits decreases. Eventually it decreases to the point of where your pressure switch turns on the pump and the pump now refills and re-pressurizes the tank.

So as Pilot Dane has indicated, the pressure tank does not create the pressure but it does maintain it while the pump is not on. This system is designed so that you do not need your pump to come on for every little bit of water you need. The less your pump cycles on, the longer is will last. Pumps are not cheap and they are certainly not easy to replace.

I hope that makes sense. All that being said, I strongly suspect your problem is a clogged up tube going to your pressure switch or the pressure switch itself. It sounds to me, from what you have said, that your tank, your pump and your water pressure gauge is all working fine. Let's hope that ends up being the case. Good luck to you.
 
  #13  
Old 02-13-18, 06:17 PM
Member
Thread Starter
Join Date: Aug 2006
Location: Columbus, OH
Posts: 149
Thanks for the additional info.

One more question:

The switch I have now is a 30/50 PSI switch. I'd like to replace it with a 40/60 PSI switch for a little extra water pressure, should I be able to that without issue?

The pressure tank is a Wellmate WM09 which has a max rating of 100 PSI and was initially pre-charged at 40 PSI, so it seems that it should be fine. I don't know anything about my pump, however, which I suspect is going to be an issue for determining if it'll be OK.
 
  #14  
Old 02-13-18, 06:33 PM
Group Moderator
Join Date: Mar 2003
Location: NC, USA
Posts: 17,597
Yes, you can use the higher pressure switch. If it's actually turning the pump on at 40 psi set your pressure tank to 37-38 psi air pressure. Don't rely on your tank's initial 40psi charging at the factory. Check it with a tire pressure gauge while you have the system bled down to install the new pressure switch.

Unless your pump is totally shot it should easily get up to the slightly higher pressure. I wouldn't worry about it and go ahead and put in the higher pressure switch.
 
  #15  
Old 02-18-18, 01:08 PM
Member
Thread Starter
Join Date: Aug 2006
Location: Columbus, OH
Posts: 149
OK, here's the update.

I purchased an Everbilt 40/60 switch and new 3" long nipple. I cut the power to the well pump, closed the valve between the pressure tank & the house and then opened the spigot below the pressure tank to drain the tank. Once no more water was coming out, I checked the pressure in the tank. It read less than 10 PSI. Also, there was a constant hiss from the open spigot like air escaping. It stopped, or at least the volume went down, when I put my thumb over the open spigot.

I removed the old switch and pressurized the tank. It took a lot of air to get it to about 33 PSI. I then installed the new switch and closed the spigot. The tank now read only about 23 PSI. Also, the pressure gauge read the same amount. That struck me as odd as I hadn't yet turned the power on to the pump, I had only closed the spigot. I wouldn't think that should pressurize the lines, only the air side of the diaphragm or bladder.

At any rate, I re-pressurized the tank to 37 PSI, turned on the well pump and opened the valve between the tank and the house. The pressure rose to 60 PSI before the pump cut off. I ran water in the sink until it cut back on at just under 40 PSI, cutting off again at 60 PSI. It seems that I have good pressure now.

The pressure seems to be holding now, but I intend to check it periodically to be sure. I did check each toilet by flushing it and lifting the float to see if the water cut off and it did. It doesn't seem like I have a leaky toilet.

I'm concerned that I have a pressure tank with a small leak, based on the lack of pressure in the tank, the hissing when the spigot was opened and that it pressurized the lines before I turned the pump back on. Is that something I should be concerned about?
 
  #16  
Old 02-19-18, 05:31 AM
Member
Join Date: Dec 2006
Location: Canada
Posts: 526
Over time air tends to leave pressure tanks. I have a cottage on a 20/40 system where I set the air in the tank, each spring, to 18psi. Each spring a year later it reads maybe 12 or 13psi and I add more air. Not sure where it goes. I know my diaphragm is in tack, so I just shake my head and add more air. I should add, that this cottage is allowed to get to freezing temperatures over the winter. It is in Canada.

If you want to know if air is constantly escaping, at a rate higher then you would like, you can measure the amount of water you get from your pressure tank, from cut out to cut in (drawdown). A couple months later, measure it again. If air is missing your drawdown of water will reduce. To measure the drawdown, let the pump fill up the tank and then take any known volume container and fill it up, as many times as needed, until the pump kicks on again.

One last law of physics. The volume of water you get will increase with the amount of air in the tank. The volume of water you get will increase with the amount of water in the tank. To maximize this equation, the theoretical perfect amount would be a tank, where half the volume was water and half the volume was air. Since you need to leave some water in the tank and you have various different pressure switch levels, you will find that almost nobody gets more then 33% of the volume size of their tanks, in drawdown and anything above 25% of the tanks volume, in drawdown, is considered excellent.

If your drawdown decreases, overtime, it is an indication that air is being lost in the tank. That could be due to an air leak but usually is due to a ruptured diaphragm. The diaphragm is there to keep the air and water separate. If they come in contact with each other, the air will slowly dissolve into the water and your drawdown will decrease. Eventually most of the air will be gone and your pump will be cycling on just about every time you turn on a tap. That is really hard on a pump and its life gets shortened very quickly. So you should be keeping an eye on your systems water drawdown anyways.

As for the pressure change when you closed the spigot. Another mystery of the mind. Trust me. There are a lot more. Always good stuff to remember if a new problem arises. Maybe others can shed more light on it. My first thought was pressures from elevations. In other words if the upstairs water was now allowed to flow to the basement, where your gauge was, that would increase the pressure measured, but doesn't sound like that happened, It was my first thought.
 
Reply

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Thread Tools
Search this Thread
Display Modes
'