Submersible pumps don't fail on a schedule. Some last decades; others die early from short cycling, sand, lightning or running a well dry. When an installer confirms the motor or pump end is finished, replacement means pulling everything out of the casing, swapping the unit, and lowering it back in. Here is what that involves on a typical well around Oklahoma City.
Signs the pump itself is done
- The motor won't start even though power, switch and control box test good.
- Amp readings show a seized or shorted motor.
- Flow and pressure have dropped steadily over months with no leak to explain it.
- Sand or grit is showing up in fixtures and the pump has worn from it.
Sizing a new pump to your well
A replacement should match the well, not just the old pump's label. The installer will want to know:
- Well depth and pump setting. How far down the pump hangs and how far the water has to be lifted.
- Static and pumping water level. Where water stands at rest and how far it drops when the pump runs.
- Yield. How many gallons a minute the well can keep up with. A pump that outruns the well will draw it down and run dry.
- Household and outdoor demand. Bathrooms, livestock, a garden or a shop all change the numbers.
Much of that is written down already if your well was drilled by a licensed contractor. Oklahoma drillers must file a completion report, the well log, within 60 days of finishing a new well. OWRB keeps those reports in a searchable database (OWRB owner's guide; OWRB Water Well Search). A log listing total depth, first water and yield gives the installer a head start before the truck even rolls.
Dry taps or a pump that won't quit? One call gets you to a licensed pump installer near you. (405) 536-9841
Pulling the pump on a Garber-Wellington well
Wells into the sandstone of the Central Oklahoma aquifer vary in depth. USGS notes shallow domestic wells under 300 feet, while city supply wells at Norman run 600 to 800 feet (USGS). The deeper the pump, the more pipe and wire come up, and the more a pump hoist is needed instead of hands. That is a big part of why replacement prices vary from one well to the next.
What else to replace while it's out
- Corroded drop pipe or worn torque arrestors.
- Splices and wire that are cracked or brittle.
- A check valve that has been leaking back.
- The pressure switch, if it is pitted or old, and a pressure tank that has lost its charge (see pressure tanks).
After the new pump goes in
Expect the installer to seal the casing with a watertight vented cap, disinfect the well at the strength the state requires, then run it to clear the chlorine (OAC 785:35-9-1). Run a bacteria test once the chlorine is gone. If the pump died because the well can't keep up anymore, ask whether lowering the pump, a new well, or drilling deeper makes more sense.
FAQ
How long does a well pump last?
There is no fixed number. Short cycling, sand, lightning and running the well dry all shorten pump life. Fixing whatever killed the old pump keeps the new one from going the same way.
Should I go bigger on horsepower?
Not automatically. A pump that pulls more than the well can supply will draw the water down to the intake. The installer should size it from your well's depth, water level and yield.
Where do I find my well depth?
Check closing papers, then OWRB's well record search. Licensed drillers have filed completion reports with the state for decades. Older or owner-drilled wells may not have a record.