Signs the Next St. Louis Storm Might Cause Your Sump Pump to Fail

A sump pump only has one job, and it usually only fails when you need it most.

A sump pump is one of those pieces of equipment nobody thinks about until it doesn’t work. It sits quietly in a basement pit for months, doing its one job in total obscurity. The only time you might notice it is during a heavy rain.

That’s not just a St. Louis homeowner’s paranoia talking. According to ARS/Rescue Rooter’s analysis of Google search data, St. Louis ranks fourth nationally for “flooded basement” searches. The reasons are local. Clay soil drains poorly, pushing groundwater against foundations instead of letting it soak away. Add older housing stock and summer storms that arrive like clockwork, and the ranking makes sense. If your pump has quietly done its job for years, heavy rain is when its weaknesses surface.

The Short Version: When to Call a Plumber

If you only read this far, here’s the part that matters. Give us a call sooner rather than later if:

• Your sump pump is 8 or more years old and you’ve never had it inspected
• It’s making new or unusual noises
• It’s cycling on and off rapidly without much rain
• The battery backup won’t hold a charge or you don’t have one
• Your basement has taken on water even once in recent memory
• You’re not confident the discharge line is clear and draining away from the house

None of these mean a flood is imminent. They mean it’s worth getting ahead of the problem while you still can. Planning for a repair or replacement beats reacting to one at 2 a.m. during a downpour. And if that’s exactly when you’re reading this, we offer 24/7 emergency service at (314) 962-0956.

The rest of this article covers lifespan, the warning signs in detail, and how to test yours yourself.

How Long Should a Sump Pump Last?

Most sump pumps have a working life of about 7 to 10 years. That figure holds up across manufacturer guidance from Zoeller, American Family Insurance’s homeowner resources, and ARS/Rescue Rooter’s service data. It holds for both pedestal and submersible pumps, as long as they’re reasonably maintained.

Age alone isn’t a guarantee of failure, but it’s the single biggest factor. A pump nearing or past the 10-year mark is worth a closer look, even if it seems fine. The internal parts, the impeller, the float switch, the seals, wear gradually and often fail without warning.

If you don’t know how old your sump pump is, that’s worth finding out. It’s usually printed on a label on the unit. A past inspection or purchase disclosure may also list the install date.

Warning Signs Worth Paying Attention To

Fortunately, a sump pump rarely fails instantly and completely. It usually gives warning signs first, like a “check engine” light that’s easy to ignore until the pump quits. Here’s what’s worth checking for:

It won’t turn on, or it runs constantly. Both are signs of a problem, just different ones. A pump that won’t activate when water rises has a dead float switch, an electrical issue, or a failed motor. When a pump never shuts off, it’s either stuck on or fighting a problem it can’t keep up with. That’s often a clogged discharge line or a leak outpacing the pump.

It’s noisy or vibrates more than it used to. Zoeller, one of the largest pump makers, points to a broken part or an unbalanced impeller as the usual culprits. Pumps get a little louder with age. But a sudden change, especially grinding or rattling, shouldn’t be tuned out.

It’s hot to the touch after running. This usually points to a motor that’s struggling and overheating, often a sign it’s near the end of its life.

It cycles on and off rapidly, in short bursts. This is a classic sign of a failing check valve. That valve is supposed to stop water from flowing back into the pit after the pump shuts off. When it fails, the pump restarts almost immediately to move the same water again and again, like a tiny mechanical Sisyphus.

Visible rust, corrosion, or an odor coming from the pit. Corrosion on the housing or fittings suggests age-related wear. A persistent odor can mean standing water that isn’t being pumped out properly (also gross, frankly).

Don’t Forget the Battery Backup

A sump pump that runs on electricity alone has a weak point. It does nothing during a power outage, which is exactly when storms tend to cause one. That’s where a battery backup comes in, keeping water moving out of the pit when the power drops mid-storm.

Battery backups should be tested regularly, and the battery itself doesn’t last forever. Zoeller’s AGM backup battery, for example, is rated for a 4 to 5 year service life with a 3-year warranty. Other types run shorter. Capacity degrades in ways that aren’t obvious until the moment it’s needed. Replace it on a schedule rather than waiting for it to fail.

Some homeowners go a different route with a water-powered backup pump. Instead of a battery, it uses your home’s water pressure to siphon water out of the pit. There’s no battery to test, charge, or replace. The tradeoff: it depends entirely on strong, reliable city water pressure, which isn’t a given everywhere we serve. Weighing this option? Call us at (314) 962-0956 or request a service visit, and we’ll say whether it fits your home.

If your home has no battery backup at all, that’s worth a conversation. It matters most if your basement has flooded before, or if the pump is your only defense against a high water table. Weighing a full upgrade instead of just adding a backup? Check out our post, Is a Smart Sump Pump Worth It?

How to Test Your Sump Pump Yourself

This takes about five minutes and doesn’t require any tools. Family Handyman and This Old House both recommend the same basic water test. Do it at least once a year:

1. Locate the sump pit and make sure the pump is plugged in and the float switch moves freely.
2. Fill a five-gallon bucket and pour it into the pit slowly, the way a real storm would fill it.
3. Watch for the float switch to rise and trigger the pump.
4. Confirm the pump draws the water down and shuts off cleanly once the pit is mostly empty. A small amount of remaining water is normal.
5. If you have a battery backup, run the test again with the pump unplugged. That confirms it works on battery power alone, like it would in an outage.
6. Check the discharge line outside. Water should exit well away from the foundation, not just out of the pit. NDSU Extension recommends discharging at least 20 feet from the house. Never route it into a sanitary sewer or septic system, which it can overload.

If the pump hesitates, struggles, or doesn’t fully drain the pit, act before the next storm rather than after.

What Linek Plumbing Company Looks For

When we look at a sump pump system, we’re not just checking whether it turns on. We check the age of the unit, the condition of the check valve, and whether the battery backup is reliable. We also look at where the discharge line sends the water once it leaves the pit. A pump that pushes water right back toward the foundation isn’t doing its job, even if it looks fine.

We’d rather walk you through what we’re seeing and why it matters than just swap a part and move on. If you’re not sure where your sump pump stands, it’s worth a second set of eyes before storm season tests it. You can read more on our sump pump installation and repair page. Or just call, and we’ll send a licensed plumber, not a salesperson, to take a look.

Frequently Asked Questions