The short answer
Common Causes for Rapid Cycling
A sump pump that cycles every minute is often reacting to a constant inflow of water. This could be from a leaking pipe, a high water table, or runoff from heavy rain. In wet winters, the ground stays saturated, so the pit refills quickly after each pump cycle.
Another frequent cause is a stuck or misadjusted float switch. If the float is caught on the pump cord or the pit wall, it may turn the pump on and off too quickly. Also check the check valve: if it fails, water flows back into the pit after the pump stops, causing the pump to start again.
Check the Float Switch and Check Valve
Start by watching the pump cycle. If the pump runs for a few seconds and then stops, the float may be set too high or too low. Adjust the float's travel range so the pump runs longer and less often. Make sure the float swings freely and isn't tangled.
The check valve sits on the discharge pipe and prevents water from returning. If it's stuck open, water drains back into the pit, triggering a new cycle. Listen for a thud or gurgle after the pump stops; that indicates backflow. Replacing a faulty check valve often fixes rapid cycling.
- Inspect the float switch for debris or tangles
- Test the check valve by feeling the pipe after the pump stops
- Clean the pit floor to remove silt and stones
- Verify the pump's discharge pipe isn't blocked
- Check the pit inlet pipe for leaks or drips
- Confirm the pump's horsepower matches the pit size
Is the Pump Too Small or Too Big?
An undersized pump cannot keep up with a high inflow, so it runs frequently. An oversized pump may empty the pit too fast, then restart quickly as water returns. Both situations cause short cycling. The pump's capacity should match the typical inflow rate.
You can measure the pit's fill rate by timing how long it takes to refill after a cycle. If the water level rises several inches in a minute, the inflow is high. In that case, a larger pump or a second pump might be needed, but that's a job for a local water damage pro.
Groundwater and Drainage Issues
A high water table can keep the pit full, especially after prolonged rain. If your sump pump runs every minute during wet seasons, groundwater may be seeping through the foundation or the pit walls. Improving drainage around the home, such as extending downspouts, can reduce inflow.
Also inspect the pit itself for cracks or loose fittings. Water can enter through the lid or the pipe penetrations. Sealing these gaps may slow the refill rate. If the problem persists, a water damage inspection can identify hidden leaks or drainage failures.
When to Call a Professional
If you've checked the float, check valve, and pit and the pump still runs every minute, the issue may be a buried pipe leak or a failing pump motor. A professional can test the pump's performance and inspect the discharge line for blockages or breaks.
A local water damage pro can also measure the water inflow and recommend a pump size that matches your situation. They can check for foundation drainage problems and suggest solutions. Acting quickly reduces the risk of pump burnout and water damage to your basement.
- Rapid cycling wears out the motor and switch
- Constant water flow can overwhelm the pit
- A failing pump may overheat and stop working
- Hidden pipe leaks waste water and increase bills
- Foundation cracks allow extra groundwater in
- A pro can test pump capacity and discharge flow
Water damage does not wait
Phones are answered 24/7 for Redmond and nearby communities.
Call Now (425) 407-5186Frequently asked questions
How often should a sump pump run normally?
A sump pump typically runs once every few hours, not every minute. If it runs constantly or very frequently, something is wrong. Normal cycling depends on the water table and pump size. If you notice rapid cycling, investigate the causes listed above.
Can a stuck float switch cause the pump to run every minute?
Yes, a stuck float switch can make the pump turn on and off rapidly. If the float is caught on the pump cord or pit wall, it may not move smoothly. Adjust or release the float so it rises and falls without obstruction. If it's damaged, replace it.
What should I do if my sump pump keeps running after heavy rain?
After heavy rain, groundwater levels rise, so more frequent pumping is normal. If it continues for days, check for a high water table or drainage issues. Ensure downspouts direct water away from your foundation. If the pump runs nonstop, contact a professional to inspect the system.