Well Pump Runs But No Water: 9 Causes & How to Fix Each One

9 Common Causes (And How to Fix Each One)

We've ranked these from most common to least common based on our service records.

1. Low Water Level / Well Ran Dry (~30% of Cases)

This is the #1 cause we see, especially during Southern California's dry season (June–November) and drought years. Here's what happens: your well's static water level drops below the pump's intake. The pump is physically running, but it's pulling air instead of water — or it's cavitating (creating vapor bubbles) because there's not enough water to maintain suction.

This doesn't always mean your well is permanently dry. Many wells experience seasonal drawdown where the water table drops during dry months and recovers during the wet season. It can also happen if you've been running heavy water usage — filling a pool, running irrigation for hours, or if a neighbor's well is pulling from the same aquifer.

Signs it's a water level issue:

• Water was working fine earlier today or yesterday
• You notice sputtering, air bursts, or cloudy water before it stopped completely
• The problem is worse during peak usage times or after heavy irrigation
• You're in a drought period or it's late summer/fall
• Neighbors on wells are also having low water issues

What to do:

1. Turn off the pump immediately. Running dry causes overheating — you'll turn a recoverable situation into a $2,000+ pump replacement.
2. Wait 24-48 hours for the water level to recover. Some wells bounce back in hours, others take days.
3. Try the pump briefly after waiting. Run it for 30 seconds. If water flows, let it build pressure and reduce your usage.
4. If this keeps happening: Call a well service company to measure your static water level. Long-term solutions include lowering the pump deeper in the well, hydrofracturing to improve yield, or in extreme cases, drilling a new deeper well.

2. Broken or Disconnected Drop Pipe (~20% of Cases)

The drop pipe is the pipe that runs from your pump at the bottom of the well up to the surface. In most residential wells, it's 1" or 1.25" PVC or galvanized steel pipe. Over time — especially in wells with corrosive water, high mineral content, or older galvanized pipe — the drop pipe can develop cracks, corrode through, or even disconnect at a coupling.

When this happens, the pump is pushing water upward, but it's leaking out through the break and falling back into the well. You might hear the pump running normally, the amp draw looks fine, but no water reaches the surface. It's essentially pumping water in circles.

Signs it's a drop pipe issue:

• Complete, sudden loss of water (not gradual)
• Pump sounds normal — no unusual noises
• Pressure gauge never builds up, or builds very slowly
• You may hear water falling or splashing if you listen at the well head
• Often happens with older galvanized steel pipe (15+ years) or PVC in aggressive water

The fix: The entire pump assembly needs to be pulled from the well to inspect and replace the damaged pipe. This is a professional job — it requires a service truck with a hoist to safely pull potentially hundreds of feet of pipe and the pump. Cost depends on well depth: $500-$2,000+ for the pipe work, plus the service call to pull and reinstall the pump. Most pros will also inspect the pump while it's out.

3. Failed Check Valve (~15% of Cases)

Check valves are one-way valves that prevent water from flowing backwards down the well after the pump shuts off. Most well systems have at least one — either built into the pump, installed on the drop pipe, or mounted at the well head (pitless adapter). Some systems have check valves in all three locations.

Check valves can fail in two ways, and each causes different symptoms:

• Stuck closed: Water can't flow up at all. Pump runs, builds pressure in the pipe below the valve, but nothing passes through. This mimics a pump failure or dry well.
• Stuck open / worn: Water drains back into the well between pump cycles. The pump has to re-fill the entire pipe column every time it starts, causing delayed water delivery and short cycling. In severe cases, so much water drains back that the pump can't keep up.

How to test: Turn off the pump at the breaker. Watch the pressure gauge. If pressure drops more than 5 PSI in 5 minutes with all fixtures off and no household leaks, water is likely draining back through a failed check valve. You might also hear a faint rushing or gurgling sound at the well head as water falls back down.

The fix: If the failed check valve is at the well head or pitless adapter, replacement is relatively quick — $200-$400. If it's downhole on the pump or drop pipe, the pump needs to be pulled — $800-$1,500 total. We always recommend installing a check valve at the well head even if there's one on the pump, for exactly this reason.

4. Worn Pump Impellers (~12% of Cases)

Submersible pumps use a series of spinning impellers (like small turbines stacked inside the pump housing) to push water upward. Each impeller adds a stage of pressure. A typical residential pump has 7-20+ stages depending on depth.

Over time — especially in wells with sand, silt, or abrasive minerals — the impellers wear down. The edges that push water become rounded and less efficient. The motor still spins at full speed, but each stage pushes less water. It's like a propeller with chipped blades — it spins fine but doesn't move much air.

Key sign: This is almost always a gradual decline, not sudden. You notice lower pressure over weeks or months, the pump runs longer to build pressure, and eventually it can't deliver enough water to keep up with household demand. If water stopped suddenly, it's probably not worn impellers.

The fix: Impellers can't be replaced individually in the field — the pump needs to be replaced as a unit. Cost: $1,500-$4,000 installed depending on well depth and pump size. If you're in an area with sandy water, ask about sand screens or sand shrouds that protect the pump.

5. Air Lock in the System (~8% of Cases)

An air lock occurs when air gets trapped in the pump, drop pipe, or plumbing, creating a pocket that blocks water flow. Submersible pumps can usually push through small air pockets, but jet pumps (above-ground) are very susceptible to losing prime when air enters the system.

Common causes of air locks:

• The well ran dry and air entered the pipe
• Someone opened the well head or plumbing for service and didn't fully re-prime
• A leak in the suction line (jet pumps) allows air to be drawn in
• The water level dropped near the pump intake causing air entrainment

The fix for jet pumps: Turn off power. Remove the priming plug on top of the pump housing. Fill the pump and suction pipe completely with water using a hose. Replace the plug, restore power, and try again. You may need to repeat this 2-3 times — air pockets can be stubborn. If it keeps losing prime, you have a suction-side leak that needs to be found and sealed.

The fix for submersible pumps: Usually resolves itself after the pump runs for a few minutes, pushing the air through. If it doesn't, there may be a larger pocket or a secondary issue. Try cycling the pump — run for 30 seconds, off for 30 seconds, repeat several times. If air persists, call a professional.

6. Clogged Inlet or Sediment Blockage (~5% of Cases)

Sediment, scale buildup, or mineral deposits can clog the pump intake screen, the drop pipe, or the pressure tank inlet. The pump runs and may even build some pressure, but water flow is severely restricted — you might get a thin trickle or nothing at all.

This is most common in wells with high mineral content (iron, manganese, calcium carbonate) or in areas with naturally sandy aquifers. Over years, scale accumulates inside pipes and fittings, slowly narrowing the passages until flow drops to nothing.

Signs: Gradual flow reduction over months/years, rusty or discolored water, white scale visible on faucet aerators, water barely trickles even when pump is running.

The fix: Depends on where the clog is. Surface piping can sometimes be flushed or chemically treated. If the pump screen is clogged, the pump needs to be pulled and cleaned or replaced. The well itself may need to be rehabilitated (chemical treatment + surging) if the screen or perforations are clogged — $2,000-$5,000.

7. Broken Foot Valve — Jet Pumps Only (~4% of Cases)

If you have an above-ground jet pump (not a submersible), there's a foot valve at the bottom of the suction pipe inside the well. This valve keeps the pipe full of water when the pump is off — maintaining the "prime" that jet pumps need to function.

When the foot valve fails (cracks, corrodes, gets stuck open by debris), the water drains back into the well when the pump stops. Next time the pump starts, it's trying to suck air through a long vertical pipe — and jet pumps simply cannot do this. The pump runs, impellers spin, but nothing gets drawn up.

Key sign: The pump works fine for a while after you prime it manually, but the next morning (or after any period of non-use), it loses prime again and you have to re-prime.

The fix: Replace the foot valve. Since it's at the bottom of the suction pipe inside the well, this means pulling the pipe — $150-$400 for the valve and labor. If you're pulling the pipe anyway, it's a good time to inspect and replace the suction line if it's old.

8. Major Plumbing Leak (~4% of Cases)

A significant leak in your pressure plumbing — between the well and the house, in the pressure tank, or in the house plumbing — can prevent the system from building pressure. The pump pushes water, but it's flowing out of the broken pipe instead of to your faucets.

Signs: Wet spots in the yard (especially between the well and the house), unusually green grass in one area, the pump runs constantly without building pressure, you can hear running water with everything turned off, or the pressure gauge shows the pump running but pressure barely rises.

Important note: Even a single running toilet can cause problems if combined with a weak pump. A toilet with a bad flapper can waste 200+ gallons per day — and on a system that's already marginal, that constant drain can prevent pressure from building.

The fix: Find and repair the leak. Underground pipe breaks may require excavation. House plumbing leaks are usually straightforward. The key diagnostic: shut off the main valve to the house and see if the pump can build pressure in the tank. If it can — the leak is in the house. If it can't — the leak is between the well and the shutoff valve.

9. Broken Pump Shaft or Coupling (~2% of Cases)

This is rare but it happens. The motor runs — you can hear it humming, it draws normal amps — but the shaft connecting the motor to the impellers has snapped or the coupling between them has failed. The motor spins freely but nothing is mechanically connected to move water.

Signs: Sudden, complete failure (was working fine, then nothing). Motor sounds slightly different — may sound smoother or higher-pitched because there's no load on it. Amp draw is lower than normal (no-load condition). Absolutely zero water movement.

The fix: Pull and replace the pump. There's no field repair for this. Cost: $1,500-$4,000 depending on depth.

Step-by-Step Diagnostic Process

Run through these steps in order before calling for service. You may be able to identify (or even fix) the problem yourself:

Reading the Pressure Gauge (What the Numbers Tell You)

Your pressure gauge is the single most useful diagnostic tool:

• Pressure never builds at all: Major issue — dry well, broken pipe, broken pump shaft, or massive leak
• Pressure builds slowly then stalls: Worn impellers, partially clogged pipe, or small leak
• Pressure builds normally then drops immediately when pump stops: Check valve failure — water is draining back into the well
• Pressure builds when house valve is closed, drops when open: Leak inside the house plumbing
• Gauge reads but no water from faucets: Blockage between tank and house (clogged filter, closed valve, frozen pipe)

Amp Draw Diagnostics (For Pros)

If you have a clamp meter, comparing actual amp draw to the pump's nameplate rating is incredibly revealing:

• Low amps (50-70% of rated): Pump is spinning freely — dry well, broken shaft, or no load. Not moving water.
• High amps (110%+ of rated): Pump is working hard — sand ingestion, bound impellers, seized bearing, or trying to push past a blockage.
• Normal amps but no water: Problem is downstream of the pump — check valve, pipe break, or blockage above the pump.
• Amps spike then breaker trips: Electrical fault or mechanical seizure. Do not keep resetting — this is a fire hazard.

Repair Cost Breakdown (San Diego / Riverside County, 2026)

The most common fix we see? Pressure tank or check valve replacement — typically $300-$800 total. Pump replacement is the most expensive common repair, but it's necessary when impellers are worn or the pump has been damaged by running dry.

When to Call a Professional

Some of these issues are DIY-diagnosable (checking for leaks, testing the pressure gauge, re-priming a jet pump). But call a licensed well service contractor when:

• You've run through the diagnostic checklist and can't identify the cause
• The pump needs to be pulled from the well (requires specialized equipment)
• You're not comfortable working around 230V electrical systems
• The well may have run dry and you need a water level measurement
• The breaker trips when the pump tries to run
• You suspect a downhole pipe break or check valve failure

Frequently Asked Questions