Pump cycles even with no water being drawn

Users who are viewing this thread

eltinnc

New Member
Messages
20
Reaction score
0
Points
1
Location
North Carolina
The problem here is a pump that constantly cycles on and off, even with all water to the house shut off. The cycle runs from on at 28 PSI to off at around 110 PSI (pressure gauge's scale only goes to 100 and it's off the scale), then drops back to 28 and starts over. Backing off the cut-off adjustment on the pressure switch has no effect on the upper limit. Closing the main shutoff on the house side of the pressure tank does not stop the cycling. Closing the shutoff on the well side does stop the cycling.

Any help in diagnosing this will be much appreciated. Thank you in advance!
 

Reach4

Well-Known Member
Messages
38,798
Reaction score
4,412
Points
113
Location
IL
Could be a bad pressure tank. Very likely. Check the precharge air with the water pressure at zero. If the air is gone or water comes out, replace the pressure tank.

If that does not seem to explain things, here are 2 questions:

Cycles how frequently?

How long is the pressure over 100 -- fraction of a second?

You should not shut off the path from the pump to the pressure switch because the pump will be building very high pressure. Something may be destroyed, plus without flow, the pump will overheat.
 

eltinnc

New Member
Messages
20
Reaction score
0
Points
1
Location
North Carolina
Could be a bad pressure tank. Very likely. Check the precharge air with the water pressure at zero. If the air is gone or water comes out, replace the pressure tank.
I did that, and the air pressure was indeed gone. I inflated it to 38 PSI, and the pressure appeared to hold.
If that does not seem to explain things, here are 2 questions:
Cycles how frequently?
Probably takes about 2 minutes to complete a cycle from 28 to 110 and back to 28. Starts over immediately
How long is the pressure over 100 -- fraction of a second?
Several seconds. Maybe 8-10
You should not shut off the path from the pump to the pressure switch because the pump will be building very high pressure. Something may be destroyed, plus without flow, the pump will overheat.
I did so only long enough to determine whether the pressure loss was on the house side or the well side. But thank you for that word of caution. I really do appreciate it.

Since the pressure loss is on the well side, would that indicate backflow to the well? Is that normal?

Thank you again!
 

Reach4

Well-Known Member
Messages
38,798
Reaction score
4,412
Points
113
Location
IL
Since the pressure loss is on the well side, would that indicate backflow to the well? Is that normal?
Not normal.

Now that you have the precharge air up, I presume that has changed your symptoms. what happens now?

Presuming that you have a submersible pump, there should be a check valve in the pump or a little above the pump. So your symptom would seem to either indicate a failure in that check valve or a hole in the down pipe.

If your pump is not down the well, then tell us more about your system.
 

eltinnc

New Member
Messages
20
Reaction score
0
Points
1
Location
North Carolina
Not normal.

Now that you have the precharge air up, I presume that has changed your symptoms. what happens now?
Actually it didn't change much. It slowed the cycle down just a bit and narrowed the range of the swing slightly (it had been more like 22 to 130 PSI, but that was about all that changed).
Presuming that you have a submersible pump, there should be a check valve in the pump or a little above the pump. So your symptom would seem to either indicate a failure in that check valve or a hole in the down pipe.
That's what I was wondering about. So does this appear to be a compound problem? Check valve AND pressure tank? And what about the pressure switch, since adjusting the cut-0ff did not affect the pressure?

Thanks again!
 
Last edited:

ThirdGenPump

In the Trades
Messages
184
Reaction score
29
Points
28
Location
MA
Not enough evidence to determine if there is a problem with the tank or not.

Tackle the issue with the leak first. Fix the leak. See that the tank empties when the system is off, see that it holds air when the system is off. If it's OK there change the switch and gauge.

It's still leaking when the valve to the house is closed. If that is a ball valve it's almost certainly on the well side. With gate vales it's always good to be sceptical and confirm it's not letting water past even when 'closed'

Reach4 has explained the possibility that it's leaking back into the well through a failing check valve or leak in the drop pipe. There is also the possibility it's leaking somewhere along the offset.

For trouble shooting at this point you move to the well. Depending on the system that could be in the realm of a proffesional.

You'd need to disconnect the drop pipe either at the top of the well or by means of a pitless adapter. The most sure fire sign the problem is in the well is if the water isn't holding at the top of the drop pipe. If the water is holding you'd want to pressure test both the offset and the drop pipe. If the offset is failing you're goin to be digging. If the drop pipe is failing you'll need to pull the pump.
 

Reach4

Well-Known Member
Messages
38,798
Reaction score
4,412
Points
113
Location
IL
That's what I was wondering about. So does this appear to be a compound problem? Check valve AND pressure tank? And what about the pressure switch, since adjusting the cut-0ff did not affect the pressure?
It is a strange set of symptoms. How can the pressure go up to over 100 PSI and stay there for several seconds while you have a pressure tank that should take a significant amount of water to raise the pressure? I would try to close your valve to the pump and turn off the power to the pump simultaneously while you have a high water pressure. Does the pressure stay up? If so, that points to one problem down the well, and you will need a well person to fix that.

And then while the pressure is up, measure how much water has been retained by filling up a bucket, or other measure, as many times as you can. That can tell how the drawdown of the pressure tank is. That can help diagnose the pressure tank.

And the pressure switch? And the gauge? Sigh.... maybe somebody will have a better analysis.
 

eltinnc

New Member
Messages
20
Reaction score
0
Points
1
Location
North Carolina
Not enough evidence to determine if there is a problem with the tank or not.

Tackle the issue with the leak first. Fix the leak. See that the tank empties when the system is off, see that it holds air when the system is off. If it's OK there change the switch and gauge.

It's still leaking when the valve to the house is closed. If that is a ball valve it's almost certainly on the well side. With gate vales it's always good to be sceptical and confirm it's not letting water past even when 'closed'

Reach4 has explained the possibility that it's leaking back into the well through a failing check valve or leak in the drop pipe. There is also the possibility it's leaking somewhere along the offset.

For trouble shooting at this point you move to the well. Depending on the system that could be in the realm of a proffesional.

You'd need to disconnect the drop pipe either at the top of the well or by means of a pitless adapter. The most sure fire sign the problem is in the well is if the water isn't holding at the top of the drop pipe. If the water is holding you'd want to pressure test both the offset and the drop pipe. If the offset is failing you're goin to be digging. If the drop pipe is failing you'll need to pull the pump.
Thank you (both of you!) very much. Helpful information.
 

eltinnc

New Member
Messages
20
Reaction score
0
Points
1
Location
North Carolina
If I were to install an in-line check valve on the well side of the pressure tank, does that alleviate the leak problem?
 

Reach4

Well-Known Member
Messages
38,798
Reaction score
4,412
Points
113
Location
IL
If I were to install an in-line check valve on the well side of the pressure tank, does that alleviate the leak problem?
Yes. That works around the problem, and it may work fine. You might hear a knock at pump start.
 

ThirdGenPump

In the Trades
Messages
184
Reaction score
29
Points
28
Location
MA
If I were to install an in-line check valve on the well side of the pressure tank, does that alleviate the leak problem?

Sure would. However it can create other issues.

The check at the tank can't hold a column of water more than 30 feet. If your water level in the well is or will be more than that it will prevent water from leaking back. Instead that difference will be filled with air, no connection in your system is capable of holding back against that vacuum. Then the next time the pump kicks on it will force that air up into your system.

Additiona checks can also cause water hammer when they open against each other but that's a minor issue on most residential systems.
 

eltinnc

New Member
Messages
20
Reaction score
0
Points
1
Location
North Carolina
The check at the tank can't hold a column of water more than 30 feet. If your water level in the well is or will be more than that it will prevent water from leaking back. Instead that difference will be filled with air, no connection in your system is capable of holding back against that vacuum. Then the next time the pump kicks on it will force that air up into your system.
Thank you both for your responses to my question. However, I am trying to get my mind wrapped around this one, and I'm afraid it's not quite making the stretch. Could someone please re-explain this issue? Hopefully rephrasing it will help me comprehend it better. Thank you again!
 

Valveman

Cary Austin
Staff member
Messages
14,599
Reaction score
1,296
Points
113
Location
Lubbock, Texas
Website
cyclestopvalves.com
In other words if the check valve on the pump has failed, adding an additional check valve higher up is just a Bandaid for the real problem. The BandAid will stop the pump from cycling when there is no water being used. But it will cause other problems like water hammer when the pump starts and possibly air coming out the faucets. If you want to solve the problem the check valve on the pump will need to be replaced.
 

eltinnc

New Member
Messages
20
Reaction score
0
Points
1
Location
North Carolina
Thank you for all of the above help.

Unfortunately, the real core problem, at least of the leak aspect, revealed itself in a most UGLY fashion this morning when my wife noticed water bubbling up like a fountain beneath one of the shrubs next to the house ... directly in line with the well, of course. So, I shut the pump off and called a local well service company to deal with the ruptured line. At least the source of the leak problem is identified.

Now, here's an additional question. A bit later when I temporarily turned the pump back on so my wife could shower, the bubbling fountain was now a powerful geyser sending a stream of water well above our roof line. The question: Should there be a pressure regulator on the pump? Is a failed regulator behind both the 110+ PSI readings and the rupture?

Thank you again for all your help!
 

Reach4

Well-Known Member
Messages
38,798
Reaction score
4,412
Points
113
Location
IL
The question: Should there be a pressure regulator on the pump? Is a failed regulator behind both the 110+ PSI readings and the rupture?
No. No regulator at the pump. If your pump can put out more pressure than the plumbing can handle, you should have a maybe a (90 PSI??) relief valve to release water in the case of a deadhead condition. Some put a relief valve routinely. Some others will omit that if the shut off PSI for the pump is low enough. I don't have a relief valve, but neither do I have a valve between the pump and the pressure switch.

See the img_5.png attachment. Now these pumps are not the same as your pump, but just examples I had handy. Note the Shut-off PSI rows. The column under the distance to water would be what pressure would be on your buried line if you closed that valve before the pressure switch if you had one of those pumps.

Again, your pump is probably smaller, so this is not meant to represent your pump.
 

Attachments

  • img_5.png
    img_5.png
    70.2 KB · Views: 582

eltinnc

New Member
Messages
20
Reaction score
0
Points
1
Location
North Carolina
OK, the BIG problem is resolved, the pipe from pump to house is fixed. No more leak, no more cycling, no more pressure loss; pressure holds at wherever it is when faucets are shut off.

Here's what remains. With faucet OPEN, pressure switch now clicks off at 82 PSI, and on at 14 PSI. With faucet CLOSED as pump is running, the switch clicked off at 90 PSI, but the pressure kept building and went well off the scale. I would estimate, by process of interpolation, that it topped out at about 140 PSI ... and held there. Would this continued rise after the switch clicked off have to do with air trapped somewhere? If so, would it be in the pipes, or in the pressure tank?

Do these very low and very high on/off points mean the switch is bad? As I mentioned earlier in this thread, I've tried without success to lower the cut-off adjustment. Or is the tank the problem?

Thanks again for all the help!
 

ThirdGenPump

In the Trades
Messages
184
Reaction score
29
Points
28
Location
MA
Gauge could simply be bad. To check you can use a tire pressure gauge on the tank. When the system is pressurized it should read the same. Switch could also be faulty. It's hard to identify issues without being there. There is things we might pick up on homeowner might miss.

Switches ad gauges are cheap parts that often get changed out as preventitive maintenance. I usually change switches every 10 years. I have no expectation gauges will be working more than a few years after install, they are notoriously undependable.

Change the switch, change the gauge, charge the air in the tank to 2 pounds below cut out and see if you still have a problem.

If your well guy was out to repair the line why didn't you have him look at the tank?
 

Valveman

Cary Austin
Staff member
Messages
14,599
Reaction score
1,296
Points
113
Location
Lubbock, Texas
Website
cyclestopvalves.com
I have had a couple where the pressure kept climbing even after the pump shut off. Turned out to be a tank buried underground no one knew about. It would fill first and had a lot more pressure in it than the tank at the house. After the pump shut off the buried tank would empty into the tank in the house and the pressure would go really high. Took me a while to figure the first one out. 10 seconds the second time I heard it though.
 

eltinnc

New Member
Messages
20
Reaction score
0
Points
1
Location
North Carolina
Gauge could simply be bad. To check you can use a tire pressure gauge on the tank. When the system is pressurized it should read the same.
Have done that at a few points, including at the time I last posted. Pressure at Schrader valve always matches gauge within a few PSI.
 

Reach4

Well-Known Member
Messages
38,798
Reaction score
4,412
Points
113
Location
IL
It is possible that your pressure switch is slow to respond because of a clogged nipple delaying the pressure change from being sensed by the switch. You might start by cleaning or replacing the nipple.

On to the pressure switch itself. For a Pumptrol pressure switch
To raise or lower the cut-in and cut-out settings while keeping the
differential between those two settings constant, adjust the range
nut. The range nut is the 3/8-inch nut that adjusts the larger of
the two springs in Models FSG, FYG, FRG, and Type G Pumptrol
switches.
Turn the range nut clockwise to increase the cut-in pressure and
counter-clockwise to lower the cut-in pressure. Three and a half
revolutions of the range nut will change both the cut-in and
cut-out settings by approximately 10 psi.

Adjust the differential nut if you want to raise or lower the
cut-out setting while keeping the cut-in pressure constant. The
differential nut is the 3/8-inch nut that adjusts the smaller of
the two springs in Models FSG, FYG, FRG, and Type G switches. Turn
the differential nut clockwise to increase the cut-out pressure and
counter-clockwise to lower the cut-out pressure. Adjusting the
differential nut will change only the cut-out setting while the
cut-in setting remains unchanged.​

So I would turn the nut on the smaller spring ccw until the spring is pretty much loose. That will minimize the differential.

I would turn the nut on the big spring CCW substantially to try to get pressures lower.

Or just replace the pressure switch, will come pre-adjusted to a pressure pair.
 
Top
Hey, wait a minute.

This is awkward, but...

It looks like you're using an ad blocker. We get it, but (1) terrylove.com can't live without ads, and (2) ad blockers can cause issues with videos and comments. If you'd like to support the site, please allow ads.

If any particular ad is your REASON for blocking ads, please let us know. We might be able to do something about it. Thanks.
I've Disabled AdBlock    No Thanks