Key takeaways
- A sump pump moves groundwater out of a pit in the basement floor and away from the house.
- Test it before spring and after heavy rain by filling the pit with water.
- A battery backup keeps the pump running through storm power outages.
- The discharge line can freeze or clog in winter and should drain away from the foundation.
- Noise, constant running, or a pump that will not start are signs to call a plumber.
How a sump pump works
A sump pit is a basin set into the basement floor, usually connected to drain tile that runs around the footing. When groundwater rises, it flows into the pit. A float switch, or an electronic sensor, turns the pump on when the water reaches a set level. The pump pushes the water up a discharge pipe and outside, away from the house, then shuts off when the pit is nearly empty.
There are two common types. A submersible pump sits in the pit under the water and is generally quieter. A pedestal pump has its motor above the pit on a column, and is easier to see and reach. Both do the same job.
In Ohio, where many soils hold water and spring brings both heavy rain and thawing ground, a sump pump can run often for days. That is normal, but it is also hard on a pump, which is why testing and maintenance matter.
Testing your sump pump
Test the pump a few times a year, and before spring and heavy-rain seasons. Look in the pit first. It should be free of debris, gravel and silt that could jam the float. Then slowly pour a bucket or two of water into the pit until the float rises.
Watch for the following:
- The pump starts when the float lifts.
- The water level drops steadily.
- The pump shuts off when the pit is nearly empty.
- Water flows out of the discharge pipe outside.
- The pump does not make grinding, rattling or screeching noises.
If the pump hums but does not move water, does not start, or does not shut off, have a plumber look at it. Unplug it before reaching into the pit, and do not handle a pump while standing in water. Electrical work in a wet area is a job for a pro.
Battery backups
Storms that flood basements often knock out power as well. A pump with no electricity does nothing. A battery backup, which is a second pump or a system that runs from a battery and charger, can keep water out for a limited time when the power fails.
A backup is only useful if it is maintained. Batteries wear out and need to be checked and replaced on the manufacturer's schedule. Some systems have an alarm that tells you when the main pump has failed or the water is rising too high. A plumber can help you pick a backup that suits your pit, your pump and the amount of water you usually get. Also see sump pump service for installation and replacement.
A backup is not a substitute for a working main pump, a clear discharge line and good drainage around the house.
Discharge lines and Ohio winters
The discharge line carries water out of the house and should end well away from the foundation, so the same water does not run back into the soil around the basement. In winter, water left in the line can freeze, and a frozen or ice-blocked line makes the pump work against a plug. The motor can overheat, and water backs up into the pit.
Some general precautions:
- Make sure the line slopes away from the house so it drains after the pump shuts off.
- Keep the outlet free of leaves, snow, ice and dirt.
- Check it after a hard freeze and during a winter thaw.
- Ask a plumber about a vented or freeze-resistant outlet if your line has a history of freezing.
Also check that downspouts and gutters are clear and that they discharge away from the house, since they send a lot of water to the same soil the sump pit is trying to drain.
Signs of trouble
Watch for a pump that runs constantly without lowering the water, one that cycles on and off rapidly, one that is noisy or vibrates, or one that does not start at all. A musty smell, damp walls, or water in the pit that stays high are also warnings. An old pump, or one that has run through many wet seasons, may be near the end of its life even if it still works.
If water is coming into the basement, move valuables off the floor and avoid standing water if electrical outlets or appliances are nearby. A plumber can find out whether the problem is the pump, the float, the check valve, the discharge line, or the amount of water coming in. If the issue is sewage rather than groundwater, see the guide to drains, sewer lines and basement backups, or get in touch to describe what you are seeing.
Frequently asked questions
How often should I test my sump pump?
Test it a few times a year, and especially before spring and after long dry spells. Pour water into the pit and make sure the pump starts, empties the pit and shuts off.
Is it normal for a sump pump to run constantly in spring?
During heavy rain or a thaw, a pump can run for long periods. If it runs when the weather has been dry, or never seems to lower the water, it may be failing or something is wrong with the discharge or the check valve.
Do I need a battery backup for my sump pump?
If your basement takes on water during storms and your power goes out, a backup can help keep the pit from overflowing. A plumber can tell you what size makes sense for your pit and your pump.
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