When a well pump runs but the pressure stays low, the cause is usually one of five things: a failed pressure switch, a worn pump, a leak in the line, a waterlogged pressure tank or a low well level. Read the gauge on the tank first, because the number tells you which one to chase.
Start with what the system is supposed to do
A private well system works in a loop. The pump fills a pressure tank, the tank holds water under pressure, and a pressure switch turns the pump on when pressure falls to a low setting and off when it reaches a high one. If the pump runs but the tank never builds pressure, one of those pieces is failing.
Before blaming the pump, read the pressure gauge on the tank. A healthy household system cycles between two numbers, often 30 and 50 or 40 and 60 pounds per square inch. A gauge at zero, one that climbs very slowly, or one that never reaches the cut-out point gives you a direction.
Private wells are the main water source for most properties around Sunriver and La Pine, according to Deschutes County and Oregon agency materials, so this is an everyday problem in south county. It is also common in Tumalo and on the rural edges of Bend and Sisters.
Match the symptom to the part
Several of these can overlap. A worn pump and a leaking line can both cause low pressure, which is why a plumber measures rather than guesses.
| What you see | Likely cause | What to check |
|---|---|---|
| Gauge at zero, pump silent | No power, tripped breaker or failed switch | Breaker, disconnect, switch contacts |
| Pump runs, pressure stays low | Worn pump, leak in the line or low well level | Flow test, pressure drop, drop pipe |
| Pressure rises, then drops fast | Check valve failing or leak between pump and tank | Check valve, line to the tank |
| Pump clicks on and off often | Waterlogged tank | Tank air charge and bladder |
| Pressure swings widely | Switch or tank port clogged | Switch setting and tank connection |
| Sputtering faucets with air | Low water in the well or a suction leak | Static level, suction side |
Check the easy things first
Ten minutes before you call
- Confirm the pump's breaker is on and reset it once, not repeatedly.
- Check any separate disconnect at the well house or near the tank.
- Read the pressure gauge with no water running.
- Listen at the tank for the pump starting and the clicks of the switch.
- Walk the line from the well to the house, looking for soggy ground and listening for hissing.
- In cold weather, check that the well house is warm and the switch line is not frozen.
The pressure tank is the part most often ignored
Inside the tank, a bladder or diaphragm separates water from a cushion of compressed air. The air has to be at the right pressure, usually a couple of pounds below the pump's cut-in setting. Once the air charge is gone, the tank is solid water with nothing to compress. The pump responds by switching on and off every few seconds, known as short cycling.
Short cycling wears out a pump quickly. Each start draws a surge of current and heats the motor. Replacing a tank is far cheaper than replacing a motor that cooked itself, so act early. A plumber can check the air charge with a gauge on the tank valve, with the power off and the tank drained.
A tank with a ruptured bladder cannot be recharged and needs replacement. A tank that has only lost air can often be recharged and tested again.
Do not keep resetting a tripping breaker
A breaker that trips again and again is protecting a pump from damage. Repeated resets can burn out the motor and turn a repair into a replacement.
Well level, leaks and the line to the house
Sometimes the pump is fine and the water is the problem. In dry years the water level in a well can fall below the pump's intake, and a pump that pulls air will sputter and lose pressure. A plumber or well professional can measure the level to see whether the pump needs to be lowered.
A break in the buried line keeps the pump running nonstop while pressure never recovers. A simple test closes the valve at the house and watches whether pressure holds on the well side. If it falls, the leak is in the buried line, a case for water line repair. If it holds, the leak is inside the house.
Repair or replace the pump?
Once the problem is traced to the pump, the choice is between repairing and replacing it. Pumps are mechanical parts with a service life, and age matters. A pump that has run for more than a decade, has been cycling hard or has a worn motor is often better replaced than patched.
Look at the whole picture. If the pump is old and the tank is waterlogged, replacing both at once saves a second visit. If the pump is fairly new and the failure is a switch or a check valve, a repair is usually the better value. A plumber should explain which parts failed, what each costs and what could fail next.
Ask about the pump's depth and type before you agree to a price. A submersible pump sits in the well and takes more effort to pull than a jet pump in the house. Those two facts, together with the horsepower, drive most of the quote.
When to call and what to expect
Call right away if the house has no water, if the pump is hot to the touch, or if you hear it grinding. A dry house is an emergency, and the plumber will start by reading the gauge and measuring the pump's current draw.
For a planned visit, bring the age of the pump and tank if you know them, the pump type and the last time anything was serviced. That information changes the quote. The full range of causes and costs is covered on the well pump repair page.
If your well also feeds a drip or sprinkler system, mention it, since a stuck irrigation valve can drain the system. In the La Pine area, where wells are shallow and winters are long, freeze protection is part of the repair.