Solved! Why Is My Sump Pump Running Without Rain, and What Should I Do?

Q: I’ve been noticing a constant noise coming from my basement, and I finally realized that it’s the sump pump. But it hasn’t been raining! So why is my sump pump running without rain, and should I call someone to come look at it?

A: Do sump pumps run all the time? Is it normal for a sump pump to run continuously? The simple answer, in most cases, is that it’s not normal for a sump pump to run nonstop. There are instances when it’s normal if your sump pump is always running when it’s not raining, such as if you live near a river or there’s a lot of melting snow on the ground. And a smaller sump pump may run more often than a larger pump. In general, though, it’s safe to assume a sump pump that’s working continuously without rain is experiencing an issue that needs to be fixed, and it’s time to consult a professional. There are a few troubleshooting steps you can take before hiring a plumber that may help you determine the cause of the problem. But ultimately, hiring a professional to take a look at your sump pump and diagnose the issue can save you a lot of time and money—not to mention stress.

Exterior conditions, like a rise in the water table or an increase in groundwater, could cause a sump pump to run when there’s no rain.

The water table is the boundary between the unsaturated soil above and the saturated sediment and rock below. The water table’s level can change throughout the year, usually due to an increase in rainfall. If you live close to a body or water or have had frequent rain, this could be why your sump pump is running continuously.

An increase in groundwater is one of the most common reasons your sump pump may be running without rain. A broken pipe, nearby construction, or overflowing water sources can increase the amount of groundwater, which can then pool at the bottom of your home and turn your sump pump on. If groundwater or your water table is causing your sump pump to run nonstop, it may be time to call a plumber or basement waterproofing expert to make sure the pump isn’t going to overheat or break down.

Melting snow can trigger a sump pump to run. 

If your sump pump keeps running with no rain in sight, it could be the result of melting snow. Say it recently snowed in your area, but now the temperature has risen above freezing. This could cause the snow to melt, turn into water, and seep into the ground. Although your landscaping may absorb some water, the excess may still trigger your sump pump to run. It’s good for it to run in this case, since you don’t want to risk excess moisture entering your home or compromising your foundation—as long as the sump pump stops running once the snow has fully melted and the ground has dried.

A broken float switch could be the reason a sump pump is running with no rain.

Your sump pump system likely includes a float switch, which floats up when water rises in the sump pit and triggers the switch that turns the pump on. In most cases, when the water lowers back down, the float switch drops and turns the pump off. If you have a broken float switch that doesn’t return to its original position, it could cause your sump pump to run continuously, even when there’s no water in the basin.

You can attempt to resolve the issue by manually adjusting the switch or applying a spray lubricant to it to see if the switch will move. Otherwise, it may be wise to call a plumber to take a look at it. A professional should be able to figure out what caused the broken float switch and how to repair it.

A sump pump might keep running if the drain line is clogged. 

A clogged drain line in your sump pump is a surefire way to keep it running, even if the sun is shining and there’s no rain in the forecast. Depending on how long you’ve had your sump pump, its drain line can fill with dirt and debris that make it hard to let water pass through. If water can’t drain, it can build up in the basin and cause the sump pump to malfunction, or, in worse cases, overheat with steam and smoke. If you’ve checked for the above scenarios and are still wondering, “Why is my sump pump running?” you may need to check and see if the drain line is clogged.

The sump pump may have failed, and you may need a professional to install a new one. 

In the worst-case scenario, you may need to have your sump pump replaced. Sump pumps last about 7 to 10 years, but they can burn out faster if they’re too small or not maintained. If you think the sump pump has failed, your best bet is to hire a professional to diagnose the failure, recommend a replacement, and install it. On average, the cost to install a sump pump is about $1,200. The final price depends on whether you need a pedestal or submersible pump, how big the sump pump needs to be, and how much labor it will take to install it. The good news is an expert will know exactly what type of sump pump you need and what tools and equipment to use to put it in place.