Sump Pump Failure: Warning Signs, Causes and What to Do
Short answer: Sump pump failure usually comes from lost power, a stuck or clogged float switch, a frozen or blocked discharge line, a worn-out motor or a pump overwhelmed by heavy inflow. If it fails, unplug and check the pump, clear the float, restore power if safe, remove the water and dry the basement within 24 to 48 hours.
A sump pump sits quietly in a pit in the basement floor and does its job until the night it doesn't. When it stops, groundwater fills the pit, spills onto the floor and soaks whatever is down there. In Littleton, that's often a finished family room. If your basement is already wet, Reestorian can connect you with a local provider for basement flood cleanup in Littleton. This guide covers the warning signs, the common causes and what to do next.
This is general information. A licensed plumber can diagnose your specific pump.
How does a sump pump work?
NDSU Extension explains that the sump may connect to drain tile that drains the house footings. Water from the tile and the surrounding soil collects in the pit. When the water rises, it lifts a float switch, which turns on the pump. The pump pushes water up through a discharge pipe and out of the house, and a check valve on the pipe keeps the water from falling back into the pit. When the level drops, the float lowers and the pump shuts off.
Signs your sump pump is failing
- The pump runs nonstop, even in dry weather
- It turns on and off rapidly in short bursts
- It hums but doesn't move water
- Grinding, rattling or gravel-like noises, which NDSU Extension says can mean the pump or float needs replacing
- The float sticks or moves sluggishly
- Water stays in the pit after the pump runs
- Visible rust on the pump or discharge pipe
- Damp floor or musty smell around the pit
Pit overflowing and water on the floor? Call to reach a local basement flood provider.
Call (928) 394-5135Why do sump pumps fail?
| Cause | What happens | What helps |
|---|---|---|
| Power outage | The pump stops during the storm that caused the outage | Battery or water-powered backup pump |
| Tripped breaker or unplugged cord | The pump has no power | Check the outlet and breaker; avoid extension cords |
| Stuck or clogged float switch | The pump never turns on, or never turns off | Clear debris; make sure the float moves freely |
| Debris in the pit | Silt and gravel clog the intake | Clean the pit; use a pit cover |
| Frozen or blocked discharge line | The pump runs but water can't leave | Keep the outlet clear of snow and ice |
| Failed check valve | Water falls back into the pit and the pump short-cycles | Replace the valve |
| Overwhelmed pump | Inflow is greater than the pump can move | Larger pump or a second pump |
| Worn-out motor | Bearings rust or the motor burns out | Replace an aging pump |
What to do when a sump pump fails
- Stay safe. Don't step into water near the pump's outlet or other electrical devices. Turn off power to the basement at the breaker if you can do it from a dry spot.
- Check power. Is the pump plugged in? Is the breaker or GFCI outlet tripped? NDSU Extension's first check is simply confirming the pump has power.
- Check the float. With the power off, look for anything holding the float down or up and clear it.
- Check the discharge line. Make sure the outside end isn't frozen, buried in snow or blocked.
- Restart and test. Restore power and pour water into the pit, as NDSU suggests, to see whether the pump starts and stops on its own at least twice.
- Remove standing water. If the floor is wet, extract the water and start drying.
- Document. Photograph the pit, the pump and the damage for your insurer.
- Call a plumber if the pump won't run or keeps failing.
How long do sump pumps last?
InterNACHI's Standard Estimated Life Expectancy Chart lists about 7 years for a sump pump. Real life varies with how often the pump runs and how clean the pit is. If your pump is near that age, or you don't know how old it is, test it more often and keep a backup ready, as NDSU Extension advises for aging pumps.
How to test your sump pump
NDSU Extension recommends these checks, especially before spring thaw:
- Confirm the pump is plugged in and the outlet works.
- Look in the pit with a flashlight for debris that could clog the pump.
- Pour water slowly into the pit until the float starts the pump. Watch and listen as it turns on and off at least twice.
- Lift the float for about 10 seconds to confirm the pump runs smoothly, then lower it.
- Check the outside discharge pipe to make sure it's clear and sends water away from the house.
- Test any backup pump the same way, and keep backup batteries in good condition.
Backup options
| Backup | How it works | Good to know |
|---|---|---|
| Battery backup pump | A second pump runs on a battery when power fails | Batteries need regular checks and eventual replacement |
| Water-powered backup | Uses household water pressure to pump the pit | Works without electricity; check local code |
| Standby generator | Powers the pump and other circuits during outages | Needs proper installation and a transfer switch |
| High-water alarm | Sounds when water rises too high in the pit | Cheap early warning |
| Second primary pump | Shares the load in pits with heavy inflow | Useful where one pump can't keep up |
Sump pumps in the south metro
Many newer homes in Highlands Ranch, Castle Rock and other parts of the south metro were built with sump pits and finished basements. Spring snowmelt and summer thunderstorms are when they work hardest. Two local points:
- Discharge in winter: If the outside line freezes, the pump may run without moving water. Keep the outlet clear and pointed away from the foundation.
- Don't connect to the sewer: The City of Littleton says not to connect sump pumps or French drains to the sanitary sewer.
Insurance after a sump pump failure
Standard homeowners policies usually don't cover sump pump overflow. The City of Littleton notes that standard homeowners and flood policies typically don't cover sewer backups or sump pump overflow, and that coverage can usually be added. Ask your agent whether you have a water backup endorsement and what its limit is, because a finished basement can exceed a low limit quickly.
After the water's gone: dry fast
The EPA says mold usually won't grow if wet materials are dried within 24 to 48 hours. Basements are cool and humid, and finished walls and carpet pad hold water. If the floor got wet beyond a small area, use commercial drying equipment and moisture readings, not just a fan. See what to do if your basement floods for the full checklist.
Local note: Sump pumps work hardest in newer subdivisions. In Highlands Ranch and Castle Rock, many finished basements rely on them. In Centennial, newer east-side homes often have sump pits. In Ken Caryl, hillside lots can send runoff toward walkout basements.
Related reading: If the basement already took on water, follow what to do if your basement floods, and watch for mold in the basement in the weeks after.
When should you call a water damage professional?
Call a plumber to repair or replace the pump. Call a water damage professional when:
- Water reached carpet, drywall or furniture
- The basement is finished or the water is more than a puddle
- Water sat for more than a day
- You smell mustiness or see stains near the floor
Sump pump failed in Littleton? Call (928) 394-5135 to reach a local basement flood cleanup provider.
Frequently asked questions
How long do sump pumps last?
InterNACHI's Standard Estimated Life Expectancy Chart lists about 7 years for a sump pump. Pumps that cycle often, run in dirty water or sit in pits with debris may wear out sooner, so test yours each spring and fall.
Is sump pump failure covered by homeowners insurance?
Usually not by a standard policy. The City of Littleton notes that standard homeowners and flood policies typically don't cover sump pump overflow. A water backup endorsement often adds that coverage, with its own limit.
Can I drain my sump pump into the sewer?
Not in Littleton. The City of Littleton says not to connect sump pumps, French drains or other flood control systems to the sanitary sewer, because the extra water can overload it and contribute to backups.
Why is my sump pump running when it isn't raining?
Groundwater can keep flowing into the pit for days after snowmelt or storms. A pump that runs nonstop in dry weather may also have a stuck float, a failed check valve letting water fall back into the pit, or a pit that is too small for the inflow.
Who should I call for sump pump replacement?
A plumber or a waterproofing contractor can replace a sump pump and add a backup. NDSU Extension suggests a new homeowner unfamiliar with sump pumps have a licensed plumber check the system before the spring thaw.
Sources
Related guides
What to Do If Your Basement Floods: A Step-by-Step Guide
Ten steps for a flooded basement, from safety and the power panel to drying, insurance and stopping it from happening again.
Mold in the Basement: Causes, Removal and Prevention
Why Colorado basements grow mold, how to get rid of it safely, when to call a pro and how to keep it from coming back.
Sump pump quit and the basement is wet?
Pump quit and water is rising? Call to reach a local provider who can pump out and dry the basement.