Well Pump Turning On And Off

One thing that we discovered after working in the house is that when we ran the water, it came out in chugs instead of a steady flow. We took a look at the well pump, and found that when the water was running it would click on for 2 seconds, then off for 2 seconds, then on for 2 seconds, and so on until the water was shut off. Having no experience with water wells or well pumps, I wasn’t sure how it was supposed to behave. Our neighbor to the south has a similar pump setup in their yard, and I noticed that their pump would come on for 30 seconds, run, then shut off. I did a bunch of internet searching, and found out that clicking on and off is called “Short Cycling” and it’s not supposed to happen. There are a few possible causes, but the most common is a loss of pressure in the storage tank.

See, in most common shallow well setups, you have a water pump and a storage tank. The storage tank is pressurized, and the pressure is what pushes water to the house. At least that’s how I understand it. When the storage tank has too much water in it, there’s no room for air and it can’t build up pressure.

Our storage tank was a ‘bladderless’ design, meaning it’s just a big metal tank with no rubber bladder inside. On the top, there’s a Schrader valve similar to what you’d find on a car or bike tire. When I pushed in the valve stem, water shot out. This means 2 things:

1. There is too much water in the tank
2. There is not enough air in the tank

Since the tank was full of water, there was no room for air. So the pump would push in a small amount until it reached the expected pressure (50psi) and then turn off. The small amount of pressure would move water to the house, and the pressure would quickly drop to 30psi where the pump would kick on again. So since the pressure was being created in small bursts and pushed to the house that way, it came out of the faucet in chugs instead of a steady stream.

In an ideal situation, there should be much more air in the tank. Things I read on the internet that the amount of air should be equal to the ‘cut in’ pressure (30psi) on the pressure switch, or others said 3psi less than that pressure. To fix this, we need to add air to the tank, but it’s already full of water. To fix this, we must:

1. Drain the water from the tank, and
B. Add air somewhere between 27 and 30psi

To do this, Tiffany shut off the power to the well pump, and I opened the water spigot that sticks out of the top of the pump. I attached a normal bicycle tire pump to the valve on the storage tank, and started pumping. As expected, the air pushed the water out of the storage tank and out of the open spigot. I did this for a while, until there wasn’t much water coming out. At that point, I closed the spigot and inflated the storage tank to about 28psi. This reading was confirmed by the pressure gauge on the pump itself, and a common tire pressure gauge.

Tiffany turned the power back on to the well pump, and the pump ran steadily and added water to the tank until the pressure reached 50psi, at which point the pump stopped. Now the moment of truth .. we opened the spigot on the pump, and water came out with good pressure and steady flow. I watched the pressure gauge, and once it got down to around 30psi the pump kicked on and ran steadily until it reached 50psi, at which point it shut off again.

Turning on the kitchen sink faucet resulted in a steady stream, and no more chugging!

 

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