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WATER PUMPS, TANKS, TESTS, WELLS, REPAIRS
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WATER HAMMER NOISE DIAGNOSE & CURE
WATER ODORS, CAUSE CURE
WATER PUMP REPAIR GUIDE
WATER PRESSURE LOSS DIAGNOSIS & REPAIR
WATER PUMP SHORT CYCLING
WATER SOFTENERS & CONDITIONERS
WATER TANK REPAIR PROCEDURES
WATER TANK: USES, TROUBLESHOOTING
WATER TESTS, CONTAMINANTS, TREATMENT
WATER TREATMENT EQUIPMENT CHOICES
WELLS CISTERNS & SPRINGS
WELL CHLORINATION & DISINFECTION
WELL FLOW RATE
WELL WATER PRESSURE DIAGNOSIS
WELL YIELD IMPROVEMENT
WINTERIZE A BUILDING
How to diganose & fix a well pump that turns on and off too frequently - short cycling well pumps. This article explains how a water pump cycling on and off problem was traced to leaks in the well piping, and how those leaks were found and repaired.
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Reader Question: My well pump is short cycling on and off but pressure in the building holds steady. I think I have a well pipe leak
I have been trouble shooting a problem with my well in my 100+ year old home over the last week and ... am asking for help in diagnosing the cause of short cycling of my water pump.
I first noticed short cycling of the pump (could hear the water hammer as pump shut off when in my well house which is also my shop) - The well would pump up to 68 psi and shut-off, then the pressure would rapidly drop to 38 and restart. I could hear water moving in the lines, but no faucets were on.
I then shut the valve upstream from the pressure tank (between the well, but before the gauge) and the pressure would hold steady (the house and all lines stayed pressurized until a faucet was opened). I figured the check valve must be out if it drained so rapidly, and I replaced the check valve, but the same problem was occurring.
That did significantly slow the cycling (from about every 15 seconds to now over a minute), but the pressure still drops when the pump clicks off. I am not having any problem with water pressure in the house lines (faucets/shower/etc).
[Our photo (left) shows a commercial type Square D 9013 Pumptrol pressure control switch. Courtesy of reader J.H.]
I am not getting any air out of any lines. I believe my well pump is working well, the pressure tank seems to be working well (with the addition of the air), I assume the foot valve is ok since I am not losing prime/pressure and I am not getting air.
I think I am dealing with a broken line/fitting underground between well/check valve and the house/pressure tank.
I have not seen any wet spots in the yard and I have been running pump all week (continues to cycle on-off about every 90 seconds). Any other ideas? Any recommendations on finding leak underground or just start digging. -- J.H.
Reply: Here are some Diagnostic Tips that May Trace Down Short Pump Cycling to a Piping Leak
[Photo at left shows a Wellxtrol auxiliary water pressure tank. In this location a small pressure tank may also serve to reduce water hammer. The main water pressure tank for this system is shown at the top of This article .]]
Watch out: before you go to the trouble and expense of replacing a water pressure tank, make sure that you have correctly diagnosed the problem that you are "curing" - you wouldn't want to replace a water tank only to find that you still have the water pressure or quantity problem because another, perhaps less costly, part was at fault.
Next Steps in Well Pump Short Cycling Diagnosis and Repair - Well Piping Leaks
Yes I have a submersible pump and what you say about air and prime makes perfect sense. I am going to start digging the well line near the well this weekend. I will take some pictures and keep you posted.
... snow finally melted here and I started digging up the yard....
I will try and get more when I find the big leak.
Definitions of Well Pump Short Cycling vs Intermittent Cycling vs Loss of Water Pressure
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.
Intermittent water pump cycling which is discussed 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.
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 SHORT CYCLING DIAGNOSIS TABLE or select a topic from the More Reading links shown below. or select a topic from the More Reading links shown below.
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