YDNAR
Jun 19, 2008, 01:53 PM
My question concerns my pump and how often it turns on when I have water running. It is an old steel tank, 80 gallons or so. There are no leaks in the system. Cut-in is at 30 lbs and cut-out is at 46 lbs. When there is no water turned on the tank will hold the pressure and the pump will not turn on, when water is running the pressure drops in a matter of 30 seconds or so and the pump starts. It takes about 30 seconds or so to pressurize at which point 30 seconds or so and we do it again, over and over as long as I have water on somewhere. I use the gravity method for replacing air in the tank, I have a drain set-up about 12 inches from bottom of tank, tank stands about 6 feet tall, about 20 inches around.
jlisenbe
Jun 19, 2008, 05:34 PM
Sounds like you have an old galvanized tank. These tanks have no "bladder" on the inside to separate the water from the air. So, the air will slowly, over several weeks, dissolve into the water until you reach the point where there is too little air left. That causes the short-cycling you are noticing. Tanks of that kind often have a method of replenishing the air as follows. When the pump cuts off, an air valve allows the water to drain back down the well, leaving the well pipe full of air. When the pump cuts back on, this air goes into the pressure tank. A valve about halfway up the side of the tank allows excessive air to escape so the tank does not become full of air. Not sure if you have such a setup or not. If you don't, you will have to charge the tank with air from time to time (through an air valve on the tank) or drain the tank empty, allowing it to fill with air, and restart the system.
Alternative: Buy and install a bladder-type tank. You will not need an 80 gallon tank for this since the bladder tanks are more efficient. If you have some plumbing skills, it is not a difficult job.