Well Pump Runs Constantly? Here's Why & How to Fix It

That humming sound from your pump house should come and go. If it doesn't stop—ever—you're racing against the clock. A well pump that runs constantly is like a car engine redlined for hours: something's going to break, and it's going to be expensive. We've seen homeowners turn a $200 pressure switch problem into a $3,000 pump replacement by waiting too long. Don't let that be you. Let's figure out what's causing your pump to run non-stop—and how to fix it before it burns out.

How a Normal Well Pump System Works

Before we dive into problems, let's understand how your well system should operate. Your well pump and pressure tank work together in a cycle:

1. Pump turns on when pressure drops to the "cut-in" point (typically 30-40 PSI)
2. Pump fills the pressure tank until pressure reaches the "cut-out" point (typically 50-60 PSI)
3. Pump shuts off and the pressurized tank supplies water to your home
4. Cycle repeats when you use enough water for pressure to drop again

When your well pump keeps running and never reaches cut-out pressure, it means either water is escaping faster than the pump can supply it, or the pressure system isn't sensing pressure correctly. Let's explore each possible cause.

7 Common Causes of a Well Pump That Won't Shut Off

1. Faulty Pressure Switch

The pressure switch is the brain of your well system—it tells the pump when to turn on and off. When it fails, your pump may never receive the signal to stop running.

Signs of a bad pressure switch:

• Pump runs continuously even when pressure gauge shows adequate pressure
• Burned or corroded contacts inside the switch
• Switch fails to "click" when pressure changes
• Erratic pump cycling (on-off-on rapidly)

DIY Check: Turn off the pump, remove the pressure switch cover, and inspect the contacts. Look for pitting, burning, or corrosion. You can gently clean contacts with fine sandpaper, but replacement is often the better solution.

Fix: Pressure switch replacement is a relatively simple repair costing $150-$300 including parts and labor. This is one of the most common fixes for a well pump that won't shut off.

2. Water Leak in Your Plumbing System

This is one of the most common reasons why your well pump is always on. If water is leaking somewhere in your system, the pump continuously tries to maintain pressure but can never reach the cut-out point.

Signs of a leak:

• Unexplained wet spots in your yard
• Water bill seems high (if on city sewer)
• Running water sound when nothing is on
• Pressure slowly drops when pump is off
• Toilets running or faucets dripping

DIY Check: Turn off all water fixtures and appliances. Watch your pressure gauge—if pressure slowly drops over 15-30 minutes with nothing running, you have a leak somewhere. Check toilets first (a common culprit), then look for wet spots around the house and yard.

Fix: Locate and repair the leak. This could be as simple as replacing a toilet flapper ($10) or as complex as repairing an underground pipe ($500-$2,000+).

3. Waterlogged Pressure Tank

Your pressure tank contains a rubber bladder that separates air from water. The air cushion allows the tank to store pressurized water and reduce pump cycling. When this bladder fails or loses air, the tank becomes "waterlogged"—filled entirely with water and no air cushion.

Signs of a waterlogged tank:

• Pump cycles on and off every few seconds (rapid cycling)
• Tank feels heavy and sounds solid when tapped (no hollow sound at top)
• Water spurts from air valve when pressed
• Tank sweats or has condensation

DIY Check: With the pump off and system drained, check the air pressure at the tank's Schrader valve (like a tire valve). It should read about 2 PSI below your cut-in pressure—so if your switch cuts in at 40 PSI, the tank should have 38 PSI of air. If little or no air comes out, the tank is waterlogged.

Fix: Sometimes you can recharge the air in the tank, but if the bladder has failed, the tank needs replacement. Pressure tank replacement costs $300-$800 depending on tank size. Learn more about our well pump repair services.

4. Failing Check Valve

The check valve sits at the top of your pump (or in the piping above it) and prevents water from flowing back down into the well when the pump stops. If this valve fails, water drains back down, the pressure drops, and the pump has to run again to refill the system.

Signs of check valve failure:

• Pump cycles frequently (every few minutes)
• Air spurts from faucets when first turned on
• Pressure drops quickly after pump shuts off
• You hear water flowing back down the well after pump stops

DIY Check: Turn off the pump when the system is pressurized. Monitor the pressure gauge—if pressure drops steadily without any water being used, the check valve may be failing (though a leak would cause the same symptom).

Fix: Check valve replacement typically costs $200-$400. If the check valve is at the pump (hundreds of feet down), this becomes a more significant job requiring the pump to be pulled.

5. Low Water Level in the Well

If your well's water level has dropped below the pump intake, the pump will run but won't produce water—or will produce very little. This causes the pump to run constantly trying to build pressure it can never achieve.

Signs of low water level:

• Sputtering, air-filled water from faucets
• Sandy or muddy water
• Problem is worse during drought or dry seasons
• Problem is worse after heavy water use
• Neighbors reporting similar issues

Why this happens: Drought conditions, increased neighborhood water usage, or a declining aquifer can all lower water tables. In some cases, the well may need deepening, or a new well may be required. See our guide on proper well depth in San Diego.

Fix: A professional can measure your static water level and determine if low water is the issue. Solutions range from lowering the pump ($1,000-$2,500), deepening the well ($5,000-$15,000), or drilling a new well. Visit our well drilling page for more information.

6. Pump Wear or Failure

Well pumps don't last forever. After 10-15 years (or sooner with heavy use or prior running issues), internal components wear out and the pump loses efficiency. A worn pump may run constantly because it simply can't produce enough pressure anymore.

Signs of pump wear:

• Gradually declining water pressure over months/years
• Pump used to shut off properly but now runs longer
• Pump is 10+ years old
• Higher than normal electricity bills
• Pump sounds different (grinding, humming)

Fix: If pump wear is the cause, replacement is the only solution. Well pump replacement costs $1,500-$3,500 or more depending on well depth and pump size.

7. Clogged or Restricted Pipe

Mineral buildup, sediment, or a damaged pipe can restrict water flow, preventing the pump from building adequate pressure.

Signs of pipe restriction:

• Reduced flow at all fixtures
• Problem developed gradually
• Hard water deposits visible on fixtures
• Old galvanized steel pipes

Fix: Pipe inspection and repair or replacement. Cost varies widely depending on location and extent of the problem.

How to Diagnose Your Well Pump Problem

Here's a systematic approach to figuring out why your well pump runs constantly:

When to DIY vs. Call a Professional

You Can Often Handle:

• Fixing a running toilet or dripping faucet
• Adding air to the pressure tank (if bladder is intact)
• Cleaning pressure switch contacts
• Replacing the pressure switch (if comfortable with electrical work)

Call a Professional For:

• Pressure tank replacement
• Check valve replacement (especially if at the pump)
• Any work involving the pump itself
• Low water level issues
• Underground leak detection and repair
• If you're unsure about the cause

The Cost of Ignoring a Constantly Running Pump

"Every hour of continuous running brings your pump closer to failure. We've seen pumps that should last 15 years burn out in weeks because owners waited too long."

Some homeowners hear their pump running constantly and think "I'll deal with it later." This is a costly mistake:

Frequently Asked Questions

Get Expert Help Today

If your well pump runs constantly and you can't identify the cause—or you've identified it but need professional help—don't wait. Every hour of continuous running brings your pump closer to failure.

At Southern California Well Service, we diagnose and repair well pump problems throughout San Diego County. Our experienced technicians can quickly identify why your pump won't shut off and provide cost-effective solutions—often the same day.