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How to diagnose, find and fix the cause of intermittent or irregular well pump cycling on and off: This article explains how to diagnose & repair water pump intermittent cycling - the water pump comes on when no water is being run in the building. Intermittent water pump cycling means that the water pump comes on for no apparent reason.
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Intermittent water pump cycling which we explain here means that the water pump comes on for no apparent reason - that is, you are unaware of any water running in the building. (When water is running in a building served by a private well and water tank and pump system it is normal for the water pump to cycle on and off to deliver water to the building.)So here we are not talking about "short cycling" (see SHORT CYCLING WATER PUMPS) in which the water pump turns on and off too frequently when water is being run in the building. However, some of the causes of "short cycling" might also lie behind "intermittent pump cycling".
Here are the more likely causes of the water pump coming on at odd times when you're not (aware of) running any water. You may want to investigate these possible causes roughly in the order they are listed below.
Contrasting Intermittent Well Pump Cycling with a Short-Cycling Water Pump Problem or with Lost Water Pressure
Short cycling of a water pump means that the water pump turns on and off too rapidly or too frequently when water is being run in the building.
If this is the problem with your water pump, see SHORT CYCLING CAUSES.
and this water tank or control repair article: Water Tank Repairs: Diagnose "Water Pump Short Cycling".
Intermittent water pump cycling which is discussed at Intermittent Water Pump Cycling When No Water is Running means that the water pump comes on for no apparent reason.
Loss of water pressure means that the pressure with which water enters a plumbing fixture has become too slow, or is sometimes too slow or weak in water flow rate, or water flow may stop entirely.
Review the list of intermittent well pump cycling provided just above and fix that cause
To correct the problem of water pumps coming on when there is no apparent reason, we need to find which of the causes listed above is occurring. Look for problems like those listed earlier in this article and fix them.
Look for other hidden causes of well pump cycling
IF that does not cure mysterious well pump cycling when you believe no one is running water in the building, look for more hidden causes such as a hidden leak in water supply piping or well piping underground.
The most common causes of hidden causes of intermittent pump cycling:
Multiple faults or causes of well pump cycling on and off?
Remember that though it's not common, on occasion more than one water pump cycling fault could be present. Each of the possible causes listed above is also discussed as a diagnosis and repair topic at this website.
Examples of how a Leaky Check Valve or Foot Valve can Cause Intermittent Water Pump Cycling
Question: Intermittent running of our well tank, tank replaced, bad foot valve?
I have a similar issue. First we experienced intermittent running of our well tank. The tank would run when we were not calling for water.
We had the tank replaced and upgraded from 20 gallons to 35 gallons. Our pressure switch is set at 30/50 psi. We were told that the valve(??) was bad because water did not shoot out and air was sucked back in when the tank was replaced. Since having the tank replaced, the psi still decreases when we're not running water. In addition a new problem has started.
Our water slows down and then stops completely for about 15 seconds during various times of the day (showers, washing dishes, etc.) and the water will spit at times (running faucets or when the toilet fills up). We verified that we have no leaks in or around the house. Our pump is submersible. Thank you very much. - Tara
Sorry, I have to make a correction. Our pressure switch is set at 40/60 psi. Thanks. - Tara
Reply: a bad foot valve can cause intermittent well pump and tank running and loss of well prime
That is, if water is being run frequently and the leaky valve is a slow leak, the pump may retain enough water to not lose prime (assuming we're talking about an above-ground well pump here). But when water is left off for a longer period and the slow leak has time to lose more water from the pump, piping, and even pressure tank, one could lose water pressure.
When your well pump is submersible (yours), you won't experience loss of prime (the pump is under water and always can prime itself). But you can see air in the well piping and water tank system and loss of water pressure as we've both described.
Follow-up from Tara: I am struggling to understand why our water stops and spits now after having the tank and valve replaced
Thank you for your reply. Our invoice states that the "check valve" was replaced. I do know that it is the valve that is very close to the well tank. Are the terms "check valve" and "foot valve" interchangeable for the same valve or are they two separate valves? As I am understanding it, I think the check valve is visible and near the tank; the foot valve is below the ground at the bottom of the submersible pump.
I am struggling to understand why our water stops and spits now after having the tank and valve replaced when we did not have this problem prior to the new tank and valve. Just tonight I have noticed a hissing sound coming from the well tank that I did not previously hear. Our plumber is on vacation this week. I am trying to educate myself as much as possible before next week. I'm concerned about assuming the problem is the foot valve and pulling up the pump as our plumber seems to want to do. I would think that if the the foot valve was leaking we would have had the loss of water all along. Thank you very much.
Tara a check valve may be at an above ground pump or at the bottom of the well (where it's better called a foot valve.) If the worker did not pull the well piping they didn't replace a foot valve. See WELL PIPING CHECK VALVES and the separate article WELL PIPING FOOT VALVES for details.
Also, we have often seen that any work on a well, pump, piping, tank and water tank system can disclose other marginal components or problems that were not obvious earlier. For example just stirring up dirt and debris in the well or well piping can cause clogging of the water pressure sensor switch leading to odd water pressure behavior, or clogging of a water filter leading to loss of pressure.
And both old water types on occasion a new bladder-type water pressure tank can suffer from a bladder that sticks to itself, preventing water from entering or leaving the pressure tank. See WATER PRESSURE TANKS, BLADDER TYPE.
Watch out: besides a bad check valve or foot valve, a leaky pipe anywhere between the bottom of the well and the building interior can also lead to intermittent water pump cycling. See WELL PIPING LEAK DIAGNOSIS or select a topic from the More Reading links shown below.
What's the difference between Well Pump Short Cycling vs Intermittent Cycling vs Loss of Water Pressure?
Intermittent water pump cycling which is discussed in the article above beginning at WATER PUMP INTERMITTENT CYCLING means that the water pump comes on for no apparent reason, perhaps when as far as you know no water is being run in the building.
Short cycling of a water pump which is defined at SHORT CYCLING WATER PUMP means that the water pump or "well pump" turns on and off too rapidly or too frequently when water is being run in the building.
If this is the problem with your water pump, SHORT CYCLING CAUSES describes the most common causes of this problem.
We also provide a complete SHORT CYCLING DIAGNOSIS TABLE that lists all possible causes of well pump rapid cycling on and off.
Loss of water pressure means that the pressure with which water enters a plumbing fixture has become too slow, or is sometimes too slow or weak in water flow rate, or water flow may stop entirely. See WATER PRESSURE LOSS DIAGNOSIS & REPAIR
Continue reading at FOOT VALVES, WELL PIPING or select a topic from the More Reading links shown below.
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Frequently Asked Questions (FAQs)
(Mar 12, 2014) Mark said:
I would describe our problem as intermittent, (roughly hourly) short cycling, (5 seconds), when no water is being run in building. Normal long cycling also occurs during water use. I am suspecting clogged or defective pressure switch and will check that next. (Deep well, submerged pump, bladder tank)
If you see water pressure below the cut in pressure try tapping on the switch. Clogging can indeed mess up switch operation.
(Mar 13, 2014) Mark said:
I drained the bladder pressure tank, then when I aired it up, the air came out the drain, I concluded that the bladder was ruptured and replaced the tank, as well as the pressure switch, for good measure. However it is still doing intermittent short cycling, (5 seconds), when no water is being run in building, and no leaks have been discovered. When the pump recharges from 30 psi to 50 psi, it takes something like a minute. I don't understand the intermittent 5 second cycling.
Mark, try turning off water into the building; if the system keeps intermittent cycling then we surmise there is a leak between the building and the well piping end inside the well itself.
Use the "Click to Show or Hide FAQs" link just above to see recently-posted questions, comments, replies, try the search box just below, or if you prefer, post a question or comment in the Comments box below and we will respond promptly.
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