- Sump Pumps & Basements
- Sump pumps
- Troubleshooting
- 7-minute read
The month matters as much as the pump. Racine County's clay soil holds a high water table for days after a spring thaw, and a pump that never stops in that window is doing its job. The same sound in a dry August is something broken.
A sump pump running constantly has one of four causes: a stuck float switch, a failed check valve letting water fall back into the pit, a pump too small for the inflow, or a high water table. In a spring thaw, two or three days of constant cycling is normal; in a dry month it is a fault.
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Key takeaways
- Listen for the pattern: a sump pump running constantly on-off every few seconds points at the check valve; on and never off points at the float or the water table.
- A pump running with no water leaving the discharge is burning out its motor — unplug it and check the float and impeller.
- Spring in Mt Pleasant, Sturtevant and low-lying Caledonia legitimately keeps pumps busy for days; August does not. Caledonia plumbers from our shop see the wet-spring version of that every year on the low-lying parcels.
- Constant running in normal weather every year is a sizing or drainage question, not a pump-replacement question.
Which of the four causes matches what you hear?
| Sound and pattern | Likely cause | Fix |
|---|---|---|
| Runs, stops, runs again every 10–30 seconds | Check valve failed — the water in the discharge pipe falls back and refills the pit | Replace the check valve |
| Runs nonstop, pit is nearly empty, discharge trickles | Float switch stuck up, or jammed against the basin wall | Free the float; replace a tethered switch with a vertical one |
| Runs nonstop, pit stays full, discharge flowing hard | Inflow exceeds pump capacity — undersized pump or a clogged discharge | Clear the line; upsize the pump or add a second |
| Runs nonstop in a wet spring, cycles normally by summer | High water table doing exactly what the tiles are designed to catch | Normal; consider a backup for outages |
| Hums but does not move water | Seized impeller or failed motor | Unplug it; replace the pump |
Is a sump pump running constantly ever normal?
Yes, in one season. Racine County sits on heavy clay. When the ground thaws in March and a rainstorm follows, the water table rises above the footing drains and stays there for days. Every tile around the house feeds the pit at once. A plumber in Franklin, WI sees exactly that on the clay subdivisions off Ryan Road.
In that window a pump cycling every minute or two for two or three days is not a fault. Watch the discharge: as long as water leaves the house each cycle and the pit level drops, the pump is winning.
Same behavior in a dry month means something is wrong. Constant running in July or August with no rain in a week points at the float, the check valve or a discharge that is draining back toward the foundation.
What should the float switch look like when you lift the lid?
Unplug the pump first
A pump that starts while your hand is in the pit is the one hazard here. Unplug both the pump and any backup.
Lift the lid and look
A tethered float should hang free; a vertical float should slide on its rod. Anything touching the basin wall, the discharge pipe or the backup pump's float can hold it up.
Move it by hand
It should swing or slide with almost no effort. A float that sticks or feels waterlogged has failed.
Plug in and watch a cycle
Pour a bucket of water in. The pump should start when the float lifts and stop when it drops, with the pit emptied to a few inches. The sump pump test guide shows the full check.
Why does a bad check valve make the pump short-cycle?
The check valve sits in the discharge pipe just above the pump and holds the column of water the pump just lifted. When it fails, that column drops straight back into the pit, the float rises, and the pump runs again to lift the same water.
Listen for a thump or a rush of water back into the basin a second after the pump stops. That is the tell. A check valve is an inexpensive part and the most common fix for a sump pump running constantly in dry weather.
Pump short-cycling or humming with no water leaving? PM replaces floats, check valves and pumps across Racine County, usually on the first visit.
Call (262) 770-0039Request serviceWhen is the pump simply too small?
A sump pump running constantly, wide open, that still cannot get ahead of the pit is undersized for the house or its discharge is restricted.
- Check the discharge line: a frozen outlet in March, a crushed corrugated extension, or a line that has settled so it drains back toward the foundation all make a good pump look weak.
- Check the outlet location: water discharged too close to the house re-enters the drain tiles and comes back around. Ten feet out and downhill is the goal.
- Match pump to lift and inflow: a basement that needs water lifted nine feet and pushed thirty feet needs more pump than the smallest unit on the shelf.
- Consider two pumps: a second primary or a battery backup pump shares the spring load and covers an outage.
Sizing is part of every PM sump pump installation in Racine; a pump that has been running constantly every spring for years is usually a pump that was never sized for the house.
Could the water be coming from somewhere else?
Sometimes the pit is fed by more than groundwater (first confirm it is a sump pit, not the sealed basin of an ejector pump). A downspout tied into the foundation tiles, a leaking water service line, or a broken lateral saturating the soil all keep a pump busy in quiet weather.
A sump pump running constantly in dry weather with a clean float and a good check valve is a reason to look at where the water is coming from. PM's pipe leak repair service traces service-line leaks, and a camera inspection checks the lateral.
Sump pump running constantly — quick answers
How long can a sump pump run continuously before it burns out?
Most residential pumps are built for intermittent duty. Hours of nonstop running in a thaw are survivable when water is moving; running dry, or against a blocked discharge, can overheat a motor in far less time.
Is it normal for a sump pump to run every 30 seconds?
During a thaw with the pit refilling that fast, yes. In dry weather, a 30-second cycle almost always means the check valve is letting the discharge column fall back into the pit, or the float is set too low.
Should I unplug a sump pump that is running constantly?
Only if it is not moving water — humming, or cycling with no flow at the outlet. If water is leaving the house, leave it running and find the cause with the pump working.
Why does my sump pump run constantly only in spring?
Because the water table in Racine County's clay soil rises above the drain tiles during thaw and rain. That is the pump doing its job; the concern is an outage in that window, which is what a backup is for.
Does a sump pump running constantly raise the electric bill much?
A typical pump draws a fraction of a kilowatt, so even days of heavy cycling cost a few dollars. The bigger cost is wear: a pump that runs constantly every spring wears out years earlier.
Three more sump pump answers
Test it, back it up, and if you are in an older Racine home, find out whether the city will pay for the conversion.
Floats, check valves, sizing and full replacements — a Master Plumber tells you which one the pump needs. Free estimates. Same crew, same license, whether you found us searching for plumbers near Racine or a neighbor sent you.
Call (262) 770-0039Request service