Sump Pump Repair: Signs, Causes, and When to Call a Plumber

A sump pump is one of those systems homeowners rarely think about until it fails, usually during the worst possible moment: a heavy spring rain or a sudden thaw. When it stops working, keeps running nonstop, or starts making strange noises, the risk of basement flooding goes up fast.

This guide walks through the most common sump pump problems, what they usually mean, roughly what repairs cost, and when it’s time to stop troubleshooting and call a professional.

Signs Your Sump Pump Needs Repair

Watch for these warning signs that your sump pump needs attention:

• – The pump doesn’t turn on when water rises in the pit
• – It runs constantly without shutting off
• – You hear banging, grinding, or rattling noises during operation
• – Water is still pooling in the basin even though the pump is running
• – There’s a foul odour coming from the sump pit
• – Visible rust or corrosion on the pump housing
• – The pump cycles on and off rapidly in short bursts

Sump Pump Not Working: Common Causes

If your sump pump won’t turn on at all, the cause is usually one of the following.

No Power or a Tripped Breaker

Check that the pump is plugged in, the outlet is working, and the GFCI hasn’t tripped. Also check your electrical panel, since a tripped breaker will cut power to the pump entirely without any other obvious warning sign.

Stuck or Broken Float Switch

The float switch tells the pump when to turn on based on water level, and it’s the single most common failure point. Constant vibration from normal operation can shift the pump inside the pit over time, causing the float to jam against the liner wall so it never rises far enough to trigger the pump.

Clogged Intake or Discharge Line

Sediment, debris, or small stones can block the intake screen or the discharge line. When that happens, the pump either can’t draw in water properly or has nowhere to send the water it does pump, which can also cause it to overheat.

Frozen Discharge Pipe

In Toronto winters, the exterior portion of a discharge line can freeze solid, especially during a deep freeze after a wet stretch. Water then has nowhere to go, and the pump can run without actually clearing the pit. Our guide on whether a sump pump can freeze covers how to prevent this every winter.

Burned-Out Motor

Pumps that run dry, overheat from a blockage, or simply reach the end of their service life can burn out the motor entirely. At that point, repair usually isn’t practical and replacement becomes the better option.

Why Does My Sump Pump Keep Running?

A sump pump that keeps running is a different problem from one that won’t start, and it usually comes down to one of these causes:

• – A stuck float switch in the “on” position, the opposite of the stuck-off scenario above
• – A faulty or missing check valve, which lets pumped water flow back down into the pit, tricking the pump into running again immediately
• – A high water table or heavy rainfall that keeps feeding the pit faster than the pump can keep up
• – An undersized pump that simply can’t move enough water for your home’s needs, which our guide on choosing the right size sump pump can help you figure out
• – A clogged discharge line that prevents the pit from ever fully draining

Sump Pump Making Noise: What Different Sounds Mean

Unusual sounds are often the earliest warning sign of a developing problem. Here’s what to listen for:

• – Banging or a loud “thunk”: Usually the check valve slamming shut as water rushes back, sometimes called water hammer. A silent check valve can often resolve this.
• – Grinding: Typically debris caught in the impeller or worn-out bearings inside the motor.
• – Gurgling or slurping: Often means the shut-off level is set too low, causing the pump to pull in air along with water.
• – Rattling: Usually a loose or poorly secured discharge pipe vibrating against the wall or floor joists.

Sump Pump Repair Cost

Repair costs depend on what’s actually wrong, but here’s a general idea of what to expect:

If your sump pump is more than seven to ten years old or has already needed multiple repairs, replacing it often costs less in the long run than continuing to patch an aging unit.

DIY Troubleshooting Steps You Can Try

Before calling for service, a few basic checks can save you time and money:

1. – Confirm the pump is plugged in and the outlet or GFCI hasn’t tripped
2. – Check your breaker panel for a tripped breaker
3. – Pour a bucket of water into the pit to see if the pump activates
4. – Inspect the float switch to make sure it isn’t obstructed and moves freely
5. – Clear visible debris from the pit and the intake screen
6. – Check the exterior discharge line for ice or blockages, especially in winter

When to Call a Plumber

Some situations call for a professional right away rather than more troubleshooting:

• – You notice a burning smell or smoke coming from the unit
• – The pump is more than seven to ten years old
• – Water is actively flooding the basement and you can’t control it
• – The pump keeps failing after you’ve tried basic fixes
• – You don’t have a battery backup and a storm is on the way

If you’re not sure who handles this kind of repair, our guide on who to call for sump pump issues walks through it.

How Drain Express Can Help

Drain Express handles both sump pump repair and sump pump installation for homeowners across the GTA, whether you need a float switch replaced or a full system upgrade. If you’re weighing a standard sump pump against a sewage ejector pump for a basement bathroom or laundry room, we can help you pick the right system. And if your basement has a history of water intrusion beyond what your sump pump can handle on its own, our basement waterproofing services address the problem at its source.

Conclusion

A sump pump that isn’t working properly, whether it won’t turn on, won’t stop running, or has started making strange noises, is not something to ignore. Catching the problem early, whether it’s a stuck float switch or a frozen discharge line, is almost always cheaper and less stressful than dealing with a flooded basement.

If basic troubleshooting hasn’t solved the problem, or you’re not confident diagnosing it yourself, reach out to Drain Express for a fast, reliable inspection. We’ve been keeping GTA basements dry for over 20 years.

Frequently Asked Questions

How Much Does Sump Pump Repair Cost?

Most repairs range from $75 to $450 depending on the issue, with float switch and check valve replacements on the lower end and motor issues on the higher end. A full pump replacement typically runs $400 to $1,200.

Why Does My Sump Pump Keep Running Even When It’s Not Raining?

This is usually caused by a stuck float switch, a failed check valve letting water flow back into the pit, or a high water table that keeps feeding the pit regardless of current weather.

Can I Fix a Sump Pump Myself?

Basic checks like confirming power, clearing debris, and testing the float switch are safe for most homeowners. Anything involving the motor, wiring, or check valve replacement is usually better left to a professional.

How Long Do Sump Pumps Typically Last?

Most sump pumps last seven to ten years with regular use. Pumps that run frequently due to a high water table may wear out sooner, while occasional use can extend that lifespan somewhat.

What is a Sump Pump Battery Backup and Do I Need One?

A battery backup keeps your sump pump running during a power outage, which is exactly when storms and flooding risk are often highest. It’s a worthwhile investment for most Toronto homes, especially older ones with a history of basement moisture.