The short answer
Common Causes
The most frequent reason is a float switch that is stuck in the up or down position, which prevents the pump from turning on or off. A tangled cord, debris, or a worn switch can cause this. Another cause is a tripped circuit breaker or a blown fuse, which leaves the pump without power even though water is present.
A blocked discharge line is also common. If the pipe that carries water away from the pit is clogged with dirt, roots, or ice, the pump will run but water will not leave. A failed check valve, which is supposed to stop water from flowing back into the pit, can also let water return after the pump shuts off.
- Float switch stuck or tangled
- Tripped breaker or blown fuse
- Clogged or frozen discharge pipe
- Failed check valve allowing backflow
- Pump too small for the groundwater inflow
- Debris blocking the pump intake
Groundwater Factors
Your sump pit collects groundwater that seeps through the foundation or floor. In a climate with cold winters and warm, humid summers, the soil around your home can hold a lot of moisture. Heavy rain or melting snow can raise the water table, causing more water to flow into the pit than usual.
If the pit is always full, the inflow may simply be higher than the pump's capacity. A pump that is undersized for the amount of water coming in will run constantly but never catch up. Also, if the pit is too small, water can fill it faster than the pump can remove it, even with a working pump.
Check the Pump First
Start by checking the power source. Look at the circuit breaker and the outlet that the pump is plugged into. Make sure the plug is fully seated and there is no visible damage to the cord. Then, lift the float switch gently to see if it moves freely and clicks when you move it.
Next, listen for the pump running. If it runs but the water level does not drop, the discharge line is likely blocked. Disconnect the pipe where it leaves the pit and see if water flows out when the pump runs. If it does, the blockage is further down the line.
If the pump does not run at all, the float may be stuck, the motor may be burned out, or there could be an electrical issue. You can test the pump by plugging it into a different outlet or checking the connections. If you are unsure, a local water damage pro can inspect the system.
Inspect the Discharge Line
The discharge line carries water from the pit to a drain, a storm sewer, or an outdoor area. Check the entire length of the pipe for kinks, bends, or blockages. In cold weather, ice can form inside the pipe and stop the flow. If the pipe exits above ground, make sure the outlet is not buried or covered.
Also, look at the check valve, which is usually installed near the pump. This valve should open when the pump pushes water and close when the pump stops. If it is stuck open, water will drain back into the pit. If it is stuck closed, water cannot escape. Tap it gently to see if it moves.
When to Call a Pro
If the pump runs, the discharge line is clear, and the pit still stays full, the problem may be with the pump itself or the groundwater flow. A pump motor can burn out, or the impeller can become damaged. In that case, the pump may need to be replaced.
If you cannot identify the cause, or if the pump is not working at all, contact a local water damage pro to inspect the system. They can test the pump, check the electrical connections, and look for hidden blockages. If you live in Detroit, keep the shutoff valve location written down so you can stop the water quickly if needed.
- Pump motor not running at all
- Discharge line clear but water level unchanged
- Frequent pump cycling or continuous running
- Visible damage to the pump or wiring
- Water backing up into the basement floor drains
Talk to someone now
Water keeps spreading into floors and walls, so it is worth acting early. Calls are answered 24/7.
Call Now (313) 766-2970Frequently asked questions
Is it normal for the sump pit to have some water in it?
A small amount of water at the bottom is normal, especially after the pump cycles off. But if the pit stays full or the pump runs every few minutes, there is likely a problem. The water level should drop noticeably when the pump activates.
Can I fix a stuck float switch myself?
Yes, you can often release a stuck float by gently lifting or moving it. Clean any debris around the switch and make sure the cord is not tangled. If the switch is damaged, it needs to be replaced. For safety, unplug the pump before touching the switch.
How do I know if the pump is too small?
If the pump runs continuously but the water level never drops, or if the pit fills faster than the pump can empty it, the pump may be undersized. A larger pump or a second pump may be needed. A pro can measure the inflow and recommend the right size.
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