Short answer
Check the power first: is it plugged in, and did the GFCI outlet or the breaker trip? Press Reset from a dry floor. Then unplug the pump and look at the float: if it is stuck against the pit wall or caught on the cord, free it. Plug it in and pour a bucket of water into the pit. If it hums but does not pump, or does not start, call a plumber.
Safety first
If the basement floor is wet, do not step in the water or touch the pump, the cord or the outlet. Turn off the basement circuit at the panel only from a dry spot, or call the power company. Always unplug the pump before you put your hands in the pit.
How to check a sump pump that will not run
1The pit fills and the pump does nothing
The water keeps rising toward the rim and the pump stays quiet. Most of the time the problem is the power or a stuck float.
Read all the steps
- The pit fills and the pump does nothing. The water keeps rising toward the rim and the pump stays quiet. Most of the time the problem is the power or a stuck float.
- Press Reset on the outlet, from a dry floor. Sump pumps usually plug into a GFCI outlet that can trip. Press its Reset button and check the breaker. Only do it with dry feet.
- Unplug it, then free the float. The float tells the pump when to start. If it is stuck against the pit wall or tangled in the cord, it never rises. Free it so it moves.
- Plug it in and test it with a bucket. Pour a bucket of water into the pit. The float should rise, the pump should start and the water level should drop within seconds.
- The water goes out through the line. Outside, the water should come out of the discharge line and drain away from the house. Clear leaves, snow or ice from the end of the line.
- Still not fixed? Call a plumber Especially if: the pump hums or runs but the water level does not drop.
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If it runs but does not pump
- The intake screen at the bottom is clogged with mud or gravel: unplug it, lift it out and rinse it.
- The check valve on the discharge line is stuck, so the water falls back into the pit.
- The discharge line is frozen or clogged outside.
- The motor is worn out: if it hums but no water moves, it needs replacing.
If it never stops running
A float stuck in the "up" position, a failed switch or a pump too small for the water coming in. A pump that never rests wears out fast, so have a plumber check it.
Be ready for the next storm
- Test the pump every few months with a bucket of water.
- A battery backup sump pump keeps working when the power goes out, which is often when storms hit.
- If your basement floods often, keep a spare pump on hand.
When to call a plumber
- The pump hums or runs but the water level does not drop.
- Water is already on the basement floor.
- It will not start even with power and a free float.
- It runs nonstop, or turns on and off every few seconds.
- The pit fills after every rain faster than the pump can keep up.
Frequently asked questions
Why is my sump pump not turning on?
Usually no power (a tripped GFCI outlet or breaker, or an unplugged cord) or a stuck float. If it has power and the float moves freely but it still does not start, the switch or the motor failed.
How do I test a sump pump?
Pour a bucket of water into the pit until the float rises. The pump should start, empty the pit in seconds and shut off on its own.
Is there a reset button on a sump pump?
Most pumps do not have one, but the GFCI outlet they plug into does. Press Reset on the outlet from a dry floor, and check the breaker.
What happens if my sump pump fails during a storm?
Water rises in the pit and can flood the basement within hours. Move things off the floor, keep away from water near outlets and call a plumber.
How long does a sump pump last?
Often 7 to 10 years, less if it runs a lot. A pump that is old, noisy or slow is worth replacing before the rainy season.
Do I need a battery backup sump pump?
If your basement takes on water during storms, yes. Storms knock out the power exactly when the pump is needed most.