Well Pump Short Cycling: Causes and Fixes

Short answer: Short cycling is when your well pump turns on and off rapidly — every few seconds to a couple of minutes — instead of running a normal cycle and resting. It is almost never a problem that fixes itself, and it is hard on the pump: every start is the hardest wear a motor takes, so a short-cycling pump can burn out months or years early. The most common causes, cheapest first, are a waterlogged pressure tank, a worn pressure switch, a mineral-clogged switch sensing tube (a Northern Nevada special), a leak or a failing check valve, and a tank that is too small for the pump. If the pump is cycling with no water at the taps, running hot, or tripping the breaker, stop using it and call — that is a call-now situation, not a watch-and-wait one.

What Normal Looks Like

A healthy well system runs in cycles with a rest in between. The pump fills the pressure tank, the tank stores water under air pressure, and the household draws from the tank until pressure drops to the cut-in point — then the pump runs again. A normal cycle lasts a minute or more of run time, with a real rest between runs.

Short cycling breaks that pattern: the pump kicks on, runs for seconds, shuts off, and kicks on again — sometimes while a single tap is running, sometimes even with every tap closed. If you can hear or feel the pump (or the pressure switch clicking) cycling rapidly, that is the symptom. The causes below are roughly in cheapest-fix-first order.

1. Waterlogged Pressure Tank

This is the most common cause, and the first thing to check. A pressure tank works because air compresses: the air cushion is what delivers water between pump runs. If the air cushion is gone — a bladder tank with a ruptured bladder, or a plain steel tank that has lost its air charge — there is almost no storage, so pressure collapses the moment a tap opens and the pump has to start again immediately.

Check: With the pump off and a tap open to drain pressure, tap the side of the tank. A healthy bladder tank sounds hollow at the top and solid at the bottom. If the whole tank sounds solid, or water comes out of the air valve (the Schrader valve on top) when you press it, the bladder has failed and the tank needs replacing — this is not a recharge-and-forget fix.

2. Pressure Switch Out of Adjustment or Worn Out

The pressure switch is the small grey box, usually on the pipe near the tank, that tells the pump when to start and stop. Switches wear: contacts pit, springs weaken, and the cut-in/cut-out gap narrows until the pump starts and stops in a tight loop. A switch that chatters — rapid clicking without a clean on or off — is a switch problem until proven otherwise.

Check: Look at the pressure gauge while the pump cycles. If the needle swings in a narrow band (for example, on at 38 and off at 42, when the system is set for 40/60), the switch gap has collapsed. Adjusting or replacing a pressure switch is a small job for a pro, and it is not a place to guess with live 240-volt wiring if you are not comfortable with it.

3. Clogged Pressure Switch Sensing Tube — the Northern Nevada Angle

This one deserves its own section because it is so common here and so often misdiagnosed. The pressure switch reads system pressure through a small sensing tube or nipple. Northern Nevada well water is hard, and mineral scale builds up inside that narrow passage until the switch can no longer read pressure accurately. The switch then sees pressure late, overshoots, and cycles erratically — a pump that looks like it has a switch or tank problem, but really has a clogged straw.

Check: This is a pro check in most cases, because it involves shutting the pump down, relieving pressure, and clearing or replacing the nipple. If your water leaves heavy scale on fixtures and the pump has started cycling for no obvious reason, mention the sensing tube specifically when you call — it saves a round of guessing.

4. A Leak, or a Check Valve Letting Water Fall Back

If the pump cycles even when no water is being used, water is going somewhere. Two usual suspects: a leak in the buried line between the well and the house, or a check valve that no longer holds. A failed check valve lets the water column in the drop pipe fall back into the well every time the pump stops, so pressure drops, the pump restarts to rebuild it, and the loop repeats — all with every tap closed.

Check: Watch the pressure gauge with all taps closed. If pressure falls steadily on its own, something is leaking or draining back. A yard that stays wet in one spot, or a pump that runs briefly every few minutes overnight, points the same way. Finding a buried-line leak is pro work; a check valve is a pump-pull job, not a driveway fix.

5. Tank Too Small for the Pump (or Pump Oversized for the House)

A pump that delivers far more water than the tank can store will satisfy pressure almost instantly and shut off, then start again the moment a tap draws a little water. This shows up after a pump replacement where the new pump is bigger than the old one, or in a house where the tank was never matched to the system. The fix is a properly sized tank, not a smaller pump setting — and it is worth getting right, because this pattern grinds a motor down faster than almost any other.

6. Electrical Problems: Low Voltage, Bad Capacitor, Overheating

Less common, but worth knowing: a pump struggling on low voltage, a failing start capacitor, or a motor overheating and cutting out on thermal protection can all look like cycling. If the pump runs, stops abruptly, will not restart for a while, then runs again — or if the breaker trips — that is an electrical or motor problem. Do not keep resetting the breaker and running it; a motor that is overheating is telling you to stop.

When to Call Now vs. Watch It

Call now if: there is no water at all, the pump runs constantly without building pressure, the pump or motor is hot to the touch, the breaker keeps tripping, or the pump cycles with every tap closed and pressure falling on its own. Any of those can turn a pump repair into a pump replacement, or a leak into water damage.

Watch briefly if: the cycling only started recently, water pressure is otherwise normal, and you have just identified a likely tank-air issue. Even then, days — not weeks — is the watch window. Short cycling is wear happening in real time.

Northern Nevada Notes

• Hard water is the local accelerant. Scale does not just clog the sensing tube; it builds up in fixtures, softeners, and tank fittings across Reno, Sparks, Fernley, and the Carson Valley. If scale is a known problem in your house, it belongs at the top of the suspect list for a cycling pump.
• Lightning and surges matter here. A summer thunderstorm surge can damage a pressure switch or a pump control box without killing the pump outright — the first symptom is often erratic cycling weeks later. If cycling started after a storm, say so when you call.
• Cycling wears pumps faster in winter too. A pump that short-cycles through a cold snap is starting far more often in the coldest, hardest conditions. Do not put this one off until spring.
• Undersized tanks are a legacy problem. Older homes around Reno and Fernley sometimes still run a small tank from a previous pump era. If a new pump went in and the cycling started right after, the tank size is the first question to ask.

Do It Yourself vs. Call a Pro

DIY: Listening for the cycle pattern, checking the tank with the tap test above, watching the pressure gauge with all taps closed, and noting when the problem started (after a pump swap, after a storm, gradually over months) are all safe, useful steps — and they make the pro's diagnosis faster and cheaper.

Call a pro: Anything involving the pressure switch wiring, the sensing tube, a check valve, a pump pull, or a tank replacement. Well systems run on 240 volts and hold pressure; the diagnosis is cheap compared with a burned-out pump, and a pro can tell in one visit whether you are looking at a tank, a switch, a tube, or a leak.

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Is Your Pump Short Cycling?

Do not wait it out — every extra cycle is wear on the motor. Call (775) 477-5515 or request a callback to book a well pump diagnosis. Reno Well & Septic is a referral service — we connect Northern Nevada homeowners with licensed independent operators who do the work.