We have a slow well. We have a well manager that consists of the following:
- a 210 gallon storage tank
- a controller that allows us to set:
--how long the well pump will run each cycle
--how long the well pump will set idle between cycles
--how long the well pump will run before being shut down because water is not flowing into the storage tank
- a pump and pressure tank to provide water to the house.
For years we have had the well manager set to run 90 seconds each cycle, to set idle for 58 minutes and 30 seconds between cycles, and to stop a cycle if water is not flowing into the storage tank after 6 seconds.
Yesterday afternoon we had no water pressure in the house. I found the storage tank was very low and the low water light was on. I found that it now takes about 12 seconds for water to flow into the storage tank.
I set the well to run for 60 seconds, set idle 59 minutes, and wait 20 seconds before shutting down for no flow. This seems to work for now.
What do you think caused the change?

 

Could there have been a voltage drop?

 

Has the water table gotten lower?

When the pump kicks on, do you notice that it stops before the 60 second or so time allotment due to the well's running dry?

Try a shorter idle time (like 39-40 minutes), and return to the 6 second stop after pumping air.

This may help if the water rises just as fast within the well but stops at a lower level that it did before.

 

The well pump is 230 volt two wire 10 horse 10 GPM. The well is about 50 feet deep. It is about 450 feet from the power disconnect at the well to the well manager in the house. With the pump running, the voltage at the well manager is 250 volts. With the pump running, the voltage at the power disconnect at the well is 245 volts.

 

The water table probably has dropped a little. I have not noticed if the well shuts off before the 60 seconds is up. I will check this and if not, I will kick the time up to 90 seconds and see if it shuts off before the 90 seconds is up. If it shuts off before 60 or 90 I will see how long it takes it to shut off. I will report back.

 

The well did not go dry after 60 seconds and after 90 seconds. I have an outside faucet that is between the well and the well manager. Tomorrow I will close the input valve to the well manager, open the outside faucet, manually turn on the well, and see how many gallons a minute will come out of the faucet.

 

New theory: A worn check valve or worn other part may have resulted in a delay before the water started. If the delay was too long then the pump shut off for pumping only air.

Simply lengthening the run before shutdown is not the permanent solution as that could shorten the life of the pump. You need to find out why it takes so long for water to appear.

Also the water table can vary week by week.

If the well did not go dry then the well pump, assuming it got as far as pumping any water, should not have shut off prematurely and then you should not have ended up with a nearly empty atorage tank.

 

The well is currently producing 3.5 gallons per minute at the faucet near the house. I do not believe the well is going dry during a 90 second pump cycle. I believe the problem is that the water is some how draining back down the line when the pump turns off. This could be a defective one way (check) valve in the pump or a leak in the line or some other cause. The line is over 400 feet long, is galvanized pipe, and has been in the ground for over 50 years. The soil is very sandy. Before installing the well manager, when the pipe was under constant pressure, we discovered a leak in the pipe and had it fixed. After installing the well manager we have found no more leaks, probably since the pipe is no longer under constant pressure and is only experiencing flow pressure during pumping and gravity pressure when not pumping.

Is 3.5 gallons per minute at the 4 foot bury depth hydrant near the house (over 400 feet from the well head) a reasonable flow from a 1/2 hp 10 gpm pump at a depth of about 50 feet flowing through a 50 year old galvanized pipe?

Is my assumption that water is draining back down the line after the pump turns off a reasonable assumption?

I think my next test will be to see how long it takes for water to flow at the well manager 10 minutes after a pump cycle completes, then 20 minutes after a pump cycle completes, then 30 minutes after a pump cycle completes. This might give me an idea of how fast the water is draining back down the line.

Any other ideas?