Why Does My Well Pump Keep Cycling On and Off?

Short Cycling: A Common Problem

If your well pump turns on and off every few seconds or minutes (called "short cycling"), it's not just annoying — it's damaging your pump. Each start puts stress on the motor. A pump that cycles 50+ times per day will fail years before its time.

Top Causes of Pump Cycling

1. Waterlogged Pressure Tank

This is the #1 cause. Your pressure tank should be about 70% air and 30% water. When the air bladder fails or air is lost, the tank fills with water and can't store pressure. Result: the pump must kick on for every small demand.

Test: Push the air valve at top of tank. Water = waterlogged. Should be air only.

Fix: Replace the pressure tank (bladder tanks last 10-15 years).

2. Faulty Pressure Switch

The pressure switch tells the pump when to start and stop. If contacts are corroded, worn, or misadjusted, it can cause erratic cycling.

Fix: Adjust or replace the pressure switch.

3. Leaks in the System

Even small leaks cause pressure drops that trigger the pump. Check:

• Toilets (running toilet is a hidden leak)
• Outdoor faucets or irrigation
• Water heater pressure relief valve
• Underground pipe leaks

4. Check Valve Failure

If the check valve at the well or pressure tank leaks, water drains back and pressure drops, triggering the pump.

Fix: Replace check valves.

5. Undersized Pressure Tank

If your water demand has increased (new bathroom, irrigation), your tank may be too small to prevent frequent cycling.

Fix: Install a larger tank or add a second tank.

How to Diagnose

1. Turn off all water in the house
2. Watch the pressure gauge — does it drop?
3. If yes, you have a leak somewhere
4. If no, check pressure tank air charge

Why It Matters

Short cycling can:

• Burn out your pump motor prematurely
• Increase electricity costs
• Cause pressure fluctuations
• Lead to complete pump failure

Don't ignore it — the longer it continues, the more damage occurs.