Rapid on-off clicking is almost always a waterlogged pressure tank that has lost its air charge, so nothing cushions the pressure between cycles. Quick test: rap on the tank, low and high, because a waterlogged one sounds solid with water all the way up instead of hollow on top. It is the fastest way to burn out a pump, so fix it right away. A bad pressure switch is the other common cause.
If your pump is clicking on and off every few seconds, that is short-cycling, and it is the single fastest way to kill a well pump. The good news is the cause is almost always a cheap part, and fixing it now protects the expensive one. Here is how to be sure.
The quick way to tell
- Count the cycle. On and off every few seconds is short-cycling; steady runs of a minute or more are normal.
- Rap on the pressure tank. It should sound hollow up top and solid at the bottom. Solid all the way up means it is waterlogged.
- Watch the gauge needle. A needle that snaps up and down fast confirms there is no air cushion left.
- Switch chattering? A worn pressure switch can flutter the pump on and off too.
Why it is cycling
A waterlogged pressure tank. This is the cause nearly every time. The tank holds an air charge that cushions the system so the pump runs in steady cycles. When that charge is gone, there is nothing to absorb the pressure, so the pump trips on and off constantly. Restoring the charge or replacing the tank fixes it.
A failing pressure switch. Less often, a worn or fluttering switch chatters the pump on and off. We check it as part of the diagnosis.
Why speed matters
Every start stresses the motor, and a short-cycling pump can start many times a minute instead of a few times an hour. Left alone, that runs a healthy pump into an early grave. Fix the tank now and you usually save the pump. Book a visit.