How much does short cycling damage a pump?

Repeated rapid starts are one of the hardest things on a pump motor and controls. Left unaddressed, short cycling can dramatically shorten pump life, so it’s worth fixing promptly — usually by restoring or replacing the pressure tank.

What pressure tank pre-charge should I use?

A common rule is to set the air pre-charge about 2 psi below the pump’s cut-in pressure, checked with the system depressurized. Confirm the right values for your specific equipment.

Well Pumps

Well Pump Short Cycling: Causes and Fixes

A pump that switches on and off rapidly is "short cycling," and it wears equipment out quickly. The most common cause is a pressure tank that has lost its air charge.

By Know Your Well Water Editorial TeamReviewed October 27, 20262 min read

Quick Answer

Short cycling is when the pump starts and stops rapidly instead of running in steady cycles. It accelerates wear and can quickly destroy a pump. By far the most common cause is a waterlogged pressure tank that has lost its air pre-charge, so there’s little stored water between the cut-in and cut-out pressures. Other causes include a wrong pre-charge setting, a faulty pressure switch, or a leak.

Why short cycling matters

Each pump start draws high current and stresses components. A healthy system lets the pressure tank supply small draws so the pump runs less often and for longer when it does. When the tank can’t store water, the pump fires repeatedly for even minor demand.

Common causes

Waterlogged pressure tank — lost or incorrect air pre-charge (most common).
A ruptured tank bladder/diaphragm.
Pre-charge not set about 2 psi below the cut-in pressure.
A failing or mis-set pressure switch.
A leak on the pressure side that keeps bleeding pressure down.

How to check (homeowner-safe)

1Watch the pressure gauge during a small draw. Rapid on/off swings confirm short cycling.
2With the pump off and pressure relieved, check the tank’s air pre-charge against the recommended value (about cut-in minus 2 psi).
3Tap the tank: a healthy tank sounds hollow on top; a tank that’s heavy throughout may be waterlogged.
4Use our Pressure Tank Calculator to confirm whether your tank gives a reasonable run time for your pump flow.

Know your limits

Recharging or replacing a pressure tank, or adjusting a pressure switch, involves a pressurized and electrically connected system. If you’re not comfortable doing it safely, call a professional — short cycling that continues will shorten the pump’s life.

Frequently asked questions

How much does short cycling damage a pump?: Repeated rapid starts are one of the hardest things on a pump motor and controls. Left unaddressed, short cycling can dramatically shorten pump life, so it’s worth fixing promptly — usually by restoring or replacing the pressure tank.
What pressure tank pre-charge should I use?: A common rule is to set the air pre-charge about 2 psi below the pump’s cut-in pressure, checked with the system depressurized. Confirm the right values for your specific equipment.

Sources & references

Protect Your Home’s Water: Private Wells — US EPA, accessed October 27, 2026

This guide is documentary research and general information, not a laboratory analysis or professional assessment of your specific well. See our disclaimer.