A submersible pump sits hundreds of feet underground, so you can't watch it wear out. What you can watch is how the system behaves at the tap and at the pressure tank. Almost every pump we replace was showing at least one of these symptoms for weeks beforehand.
1. Pressure that fades while you use water
Strong pressure for thirty seconds, then a steady fade, usually means the pump can't keep up with demand — either it's worn, the well's recovery has dropped, or the drop pipe is leaking.
2. Short cycling
If the pump clicks on and off every few seconds while a faucet runs, the pressure tank has almost certainly lost its air charge. Short cycling destroys pumps faster than anything else, so this one is urgent even though the water still works.
3. Air spitting from faucets
Air in the lines can mean the water level has dropped below the pump intake, or that there's a leak in the drop pipe pulling air in. Both need diagnosis, not a wait-and-see.
4. A rising electric bill
A pump drawing more amps than it should, or running far more often than it used to, shows up on the power bill before it shows up at the tap.
5. Sediment or cloudiness that's new
Sand and silt appearing in the water can indicate a failing screen, a cracked casing, or a pump that's now sitting too close to the bottom of the well.
6. Breakers that trip
An occasional trip when the pump starts often means a failing capacitor, a shorted motor winding, or damaged wire down the well. Repeatedly resetting the breaker risks damaging the motor further.
7. The pump never shuts off
A pump that runs continuously is either unable to reach cut-out pressure or the pressure switch has failed. Left alone, the motor overheats.
What to do next
Any one of these is worth a diagnostic visit. A test costs far less than an emergency pump pull on a Sunday, and in a good number of cases the fix is a switch or a tank rather than a pump.