Short answer: Common warning signs include a pump that runs constantly, cycles on and off rapidly, makes grinding or rattling noises, or doesn't start when you pour water into the pit. Estimates for lifespan vary: InterNACHI lists about 7 years, while HomeAdvisor says submersible pumps last 10 to 12 years.
Warning signs
- It runs all the time, even in dry weather. The switch may be stuck or the check valve may be failing.
- It turns on and off every few seconds (short cycling). The float switch may be out of adjustment or the pit may be too small.
- It makes grinding, rattling or humming noises without moving water. The motor or impeller may be failing or jammed.
- You see rust, corrosion or a burning smell around the pump.
- Water stays in the pit after the pump runs, or the pit overflows during storms.
- It's old. Knowing your pump's age is one of the best ways to replace it before it fails.
How to test your sump pump
- Make sure the pump is plugged in and the outlet works. If it's on a GFCI outlet, check that it hasn't tripped.
- Slowly pour a bucket of water into the pit until the float rises.
- Watch that the pump starts, empties the pit and shuts off on its own.
- Go outside and confirm water comes out of the discharge line and drains away from the house.
Test before spring thaw and before storm season. If the pump doesn't start, or starts but doesn't empty the pit, call for service before the next heavy rain.
How long sump pumps last
Estimates vary. InterNACHI's home life expectancy chart lists sump pumps at about 7 years. HomeAdvisor says submersible pumps typically last 10 to 12 years, and pedestal pumps can last up to 25. Pumps that run constantly in wet areas tend to wear out sooner.
Replacement and backup costs
HomeAdvisor puts sump pump replacement at $275 to $1,000, and a new installation with a pit at $642 to $2,085. A battery backup pump typically costs $600 to $1,200 installed, according to HomeServe, and replacement batteries run $120 to $200.
A backup matters most in the storms that cause the most water, because those are also the storms that knock out power. A high-water alarm is an inexpensive addition that warns you before water reaches the floor.
Frequently asked questions
Should I replace my sump pump before it fails?
If it's near the end of its expected life or showing warning signs, replacing it on your schedule is much cheaper than cleaning up a flooded basement.
Does insurance cover a flooded basement from a failed sump pump?
Standard homeowners policies typically don't. Many insurers offer a water backup and sump pump overflow endorsement. It generally covers the water damage, not the pump itself.