Short answer: First look in the pit. If water keeps flowing in, the pump may simply be handling high groundwater or snowmelt, which Bob Vila notes can be normal. If the pit is empty and the pump still runs, the float switch is probably stuck. If the pump runs but the water level does not drop, check for a clogged discharge line, a failed check valve or a worn-out pump. Pumps typically last about 7 to 10 years.
Quick diagnosis
| What you notice | Most likely cause | What to check | Call a pro? |
|---|---|---|---|
| Water keeps flowing into the pit | High water table, snowmelt or heavy rain | Watch if it stops when the ground dries | If it never stops |
| Pump runs with an empty pit | Stuck float switch | Unplug; free the float by hand | If it stays stuck |
| Pump runs, water level does not drop | Clogged or frozen discharge line, or failed pump | Check the outlet outside | Often |
| Pump cycles on and off every few seconds | Water flowing back down: bad check valve | Listen for water rushing back after it stops | Often |
| Pump is old and loud | Worn motor or impeller | Check the age | Yes |
Check the pit and the float
- Unplug the pump before reaching into the pit.
- Look for objects or debris jamming the float switch and make sure the float can move up and down freely.
- Plug it back in and pour a bucket of water into the pit. The pump should start, empty the pit and shut off.
Check the discharge line and check valve
Go outside to where the discharge pipe ends. If little or no water comes out while the pump runs, the line may be clogged with dirt or frozen in winter. The check valve (on the pipe above the pump) stops pumped water from falling back into the pit; if it fails, the pump re-pumps the same water over and over.
When the pump is just working hard
After heavy rain or snowmelt, or in homes with a high water table, a pump can run often for days. If it never gets a break, ask a plumber or waterproofing contractor whether the pump is big enough, since an overworked pump burns out early.
When to call a professional
- The pump runs constantly and the water level does not go down.
- The float is stuck and you cannot free it.
- The pump is 7 to 10 years old or older, or makes grinding noises.
- Water is rising toward the top of the pit.
What it usually costs
HomeGuide (2026) puts sump pump repairs at about $200 to $870. Parts are inexpensive (float switch about $20 to $40, check valve about $10 to $30), and a replacement pump typically costs $400 to $700 installed on average. Annual maintenance runs about $100 to $250.
Frequently asked questions
Is it normal for a sump pump to run every few minutes after rain?
Yes, during and after heavy rain or snowmelt it can. It should slow down as the ground dries.
Can a sump pump run dry?
Running dry can overheat and damage the motor, so fix a stuck float quickly.
Related problems
Sources
- Bob Vila: Why is my sump pump running without rain?
- Bob Vila: Why is my sump pump not working?
- HomeGuide: Sump pump repair cost (2026)
This guide is general information, not a substitute for an inspection by a licensed professional. See our disclaimer.