Well Pump Running Constantly: 8 Causes & How to Fix

Why This Is Urgent

A constantly running pump is an emergency. Here's why:

• Motor overheating: Submersible pumps are cooled by water flow, designed for cycles, not continuous operation
• Shortened lifespan: Continuous running can destroy a pump in weeks or months
• Higher electric bills: Pump uses electricity the entire time
• Water waste: If there's a leak, you're losing water constantly

Immediate Action

1. Turn off power to the pump at the breaker
2. Check for obvious leaks
3. Call for service if you can't identify the cause

8 Common Causes

1. Water Leak in System (Most Common — ~30%)

The most common reason a pump won't shut off: water is escaping faster than (or as fast as) the pump can build pressure. Any leak in the system — a running toilet, dripping faucet, broken irrigation valve, or cracked underground pipe — continuously drains pressure. The pump keeps running because it never reaches the cut-off pressure point.

The tricky part is that the leak doesn't have to be dramatic. A single running toilet can waste 200+ gallons per day and keep your pump from ever hitting cut-off. A slow underground leak between the well and the house may not show any visible signs for months.

How to check: Shut off the main valve to your house. If the pump can now build pressure and shut off, the leak is inside the house. If it still runs, the leak is between the well and that valve — or it's a pump/well-side issue.

Fix: Find and repair the leak. Start with toilets (food coloring test), then check faucets, irrigation, and water heater relief valve. Underground leaks may need professional leak detection. Cost: $50-$500 for most household leaks.

2. Waterlogged Pressure Tank (~25%)

Your pressure tank uses a rubber bladder to separate water and air. The air cushion is what allows the system to store pressure. When the bladder fails, the tank fills entirely with water — no air cushion means no pressure storage. The pump runs, builds pressure momentarily, but the instant any water is used, pressure drops and the pump kicks right back on. In severe cases, the pump essentially runs nonstop trying to maintain pressure in a tank with zero buffer.

How to check: Tap on the tank from bottom to top. A healthy tank sounds solid at the bottom (water) and hollow at the top (air). A waterlogged tank sounds solid all the way through. You can also check the Schrader valve (air valve) at the top — if water sprays out instead of air, the bladder has failed.

Fix: Replace the tank. Bladders can't be repaired in the field. Cost: $400-$900 for a properly sized replacement including labor. See our pressure tank sizing guide.

3. Failed Pressure Switch (~15%)

The pressure switch is the small box mounted on the pipe near your tank that reads system pressure and controls the pump. It has mechanical contacts that arc and pit over thousands of cycles. When these contacts weld together from arcing, the switch can't open the circuit — so the pump never gets the "stop" signal, even when pressure is well above cut-off.

How to check: Watch the pressure gauge while the pump runs. If pressure climbs past your normal cut-off (50 or 60 PSI) and the pump keeps running, the switch contacts are likely welded shut. Turn off the breaker immediately — overpressure can damage pipes, fittings, and the tank.

Fix: Replace the pressure switch. It's a $15-40 part, or $100-$250 with a service call. Straightforward repair.

4. Worn Pump — Can't Build Enough Pressure (~10%)

Over years of service, pump impellers wear down — especially in wells with sandy or sediment-heavy water. The motor still runs at full speed, but the worn impellers can't generate enough pressure to reach the cut-off point. The pump runs indefinitely because it literally cannot build the 50 or 60 PSI needed to trigger the switch.

How to check: Watch the pressure gauge closely. If pressure climbs slowly and maxes out below your cut-off setting (e.g., stalls at 42 PSI when cut-off is 50), the pump is worn. This is typically a gradual decline over months, not a sudden change.

Fix: Pump replacement. Cost: $1,500-$4,000 depending on well depth.

5. Leaking Check Valve (~8%)

The check valve prevents water from flowing backwards down the well. When it leaks, water slowly drains back between cycles — or even while the pump is running. The pump has to continuously replace the water that's falling back, which can prevent it from building enough net pressure to reach cut-off.

How to check: Turn off the pump briefly and watch the pressure gauge. If pressure drops more than 5 PSI in a minute or two with nothing running, water is draining back — likely through a leaking check valve. You may hear a faint rushing or gurgling at the well head.

Fix: Replace the check valve. $200-$400 if it's at the well head; $800-$1,500 if it's downhole (requires pulling the pump).

6. Low Water Level / Well Running Dry (~5%)

If your well's water level has dropped near or below the pump intake, the pump draws a mix of air and water. It can't build proper pressure with air in the system, so it runs continuously trying to compensate. You'll usually notice sputtering and air bursts from faucets before the pump starts running nonstop.

Fix: Turn off the pump to prevent dry-run damage. Wait 24-48 hours for recovery. Long-term solutions include lowering the pump, installing a storage tank, or hydrofracturing the well. Cost varies widely: $800-$15,000 depending on the approach.

7. Pressure Switch Set Too High (~4%)

If someone adjusted the pressure switch cut-off above what the pump can actually deliver, the pump will run forever chasing an impossible target. For example, a pump rated for 55 PSI max with the switch set to cut off at 60 PSI will never shut off.

Fix: Adjust the pressure switch settings. Standard residential is 30/50 or 40/60. This is often a free DIY fix if you're comfortable adjusting the switch (turn the large nut counterclockwise to lower cut-off). Or a $100-$200 service call.

8. Broken Drop Pipe (~3%)

A crack or break in the pipe between the pump and surface means the pump is pushing water up, but it's leaking back into the well through the break. The pump works fine mechanically but can't deliver water to the surface efficiently — like filling a bucket with a hole in it.

Fix: Pull the pump and replace the damaged pipe section. Cost: $500-$2,000+ depending on well depth and pipe material.

How to Diagnose

Step 1: Check Pressure Gauge

• Pressure rising slowly → leak or weak pump
• Pressure won't rise past certain point → pump can't deliver or major leak
• Pressure reaches cut-off but pump continues → switch stuck

Step 2: Look for Leaks

1. Turn off all fixtures in house
2. Check all faucets, toilets, hose bibs
3. Listen for running water
4. Check irrigation system
5. Look for wet spots in yard

Step 3: Test Pressure Tank

1. Turn off pump
2. Tap tank from top to bottom
3. Should be hollow at top, solid at bottom
4. If solid throughout = waterlogged

Step 4: Test Shut-Off

1. Close valve between tank and house
2. Turn pump on
3. Watch if it shuts off at cut-off pressure
4. If yes, leak is in house plumbing
5. If no, problem is pump, tank, or switch

Fixes by Cause

Leak Repair

• Indoor plumbing: Plumber repair
• Irrigation: Repair or cap broken heads/lines
• Underground: May need leak detection

Pressure Tank

• Recharge air if bladder is intact ($50-$150)
• Replace tank if bladder failed ($500-$1,200)

Pressure Switch

• Clean contacts (temporary fix)
• Replace switch ($100-$250 installed)

Worn Pump

• Replace pump ($1,500-$4,000)
• No repair option for worn impellers

Repair Costs

We service all major pump brands including Franklin Electric, Grundfos, Goulds (Xylem), and Sta-Rite (Pentair). Our trucks carry common parts and components for same-day repairs.

Frequently Asked Questions