Last Updated on July 13, 2026
TLDR: The Quick Answer
If your sump pump is running constantly, it is likely due to a stuck float switch, a failed check valve, or a blocked discharge line. In the Greater Toronto Area, heavy clay soil and seasonal freeze-thaw cycles often force pumps to work harder. While frequent cycling during a spring thaw is normal, a pump that never stops will eventually overheat and fail. Action: Check the float switch for debris first; if the pit is empty but the pump is still humming, unplug it and call a licensed plumber immediately to prevent motor burnout.
Understanding the “Constant Run” Phenomenon in Ontario
For homeowners in Toronto, Etobicoke, and across the GTA, the sump pump is the unsung hero of the basement. However, when that familiar hum becomes a permanent background noise, it is a signal that your flood protection system is under extreme stress.
A sump pump is designed for intermittent use. It should activate when water in the basin reaches a certain level and deactivate once that water has been discharged. When it runs nonstop, it is not just wasting electricity—it is rapidly approaching a mechanical breakdown.
Common Causes of Continuous Sump Pump Operation
The following table outlines the most frequent culprits behind a runaway pump and how they typically manifest in local homes.
| Cause | Symptom | Severity |
| Stuck Float Switch | Pump runs even when the pit is completely dry. | High (Motor burnout risk) |
| Failed Check Valve | Pump shuts off, then restarts seconds later as water flows back. | Medium (Wastes energy/wear) |
| Blocked Discharge Line | Pump runs but water level in the pit does not drop. | High (Flood risk) |
| Undersized Pump | Pump runs nonstop during heavy rain but can’t keep up. | Medium (Inefficient) |
| High Water Table | Continuous flow into the pit regardless of weather. | Low (Environmental) |
1. The Stuck Float Switch: The #1 Culprit
The float switch is a buoyant device that acts as the “on/off” trigger for your pump. In many GTA basements, vibrations from the pump can cause it to “wander” within the pit. If the float becomes wedged against the basin wall or tangled in the power cord, it stays in the “up” position, keeping the pump engaged indefinitely.
The GTA Factor: Our region’s hard water can lead to mineral scale buildup on the switch mechanism, making it less responsive and more prone to sticking.
2. The “Infinite Loop”: Check Valve Failure
The check valve is a small but critical component installed on the discharge pipe. Its job is to ensure that once water is pumped out, it cannot flow back into the pit.
If the check valve fails or is missing, the water remaining in the vertical pipe (often 8–10 feet high) rushes back into the basin the moment the pump stops. This immediately raises the float switch, triggering the pump again. This “short-cycling” can happen every 30 seconds, leading to premature motor failure.
3. Blocked or Frozen Discharge Lines
In Ontario, our winters are notorious for the “freeze-thaw” cycle. If your discharge pipe is not angled correctly or is blocked by ice, the pump will push against a solid wall of obstruction. It will run continuously, unable to move the water, until the thermal overload protection kicks in—or the motor burns out.
Information Gain: The City of Toronto Basement Flooding Subsidy
Many articles focus solely on the mechanics, but for GTA residents, there is a financial layer to this issue. As of May 1, 2026, the City of Toronto has expanded its Basement Flooding Protection Subsidy Program.
•Sump Pump Subsidy: You may be eligible for a subsidy of 80% of the invoiced cost, up to a maximum of $1,750 (including labor and materials).
•Backup Power: The city also offers up to $300 for a permanently connected battery backup for your sump pump.
•Total Protection: Combined with backwater valve subsidies, homeowners can access up to $6,650 in total funding to protect their properties.
Pro Tip: To qualify for the rebate, the work MUST be performed by a licensed plumber with a valid City of Toronto business license. Anta Plumbing is fully licensed and can assist with the necessary documentation.
GTA Soil Conditions and Hydrostatic Pressure
The Greater Toronto Area sits on a foundation of heavy clay soil, particularly in areas like Mississauga, Brampton, and parts of North York. Unlike sandy soil, which allows water to drain quickly, clay acts like a sponge, retaining moisture for long periods and expanding as it becomes saturated. This creates immense hydrostatic pressure—the force exerted by standing water—against your foundation walls and basement floor.
During a typical spring thaw in Scarborough or Etobicoke, the combination of melting snow and seasonal rainfall leads to a rapid rise in the local water table. If your sump pump is running constantly during this window, it is likely responding to the high volume of water being collected by your weeping tiles (the perforated pipes around your foundation). However, if the pump continues to cycle frequently long after the surface ground has dried, it could indicate a deeper issue. For instance, a hidden plumbing leak, such as a cracked main water service line or a compromised sewer lateral, could be continuously feeding water into your sump basin. In such cases, the pump is merely treating the symptom of a much larger problem that could eventually lead to foundation heaving or structural cracks.
The Impact of Urbanization on GTA Water Tables
As the GTA continues to grow, increased “impermeable surfaces”—like paved driveways and large patios—mean that rainwater has fewer places to soak into the ground naturally. Instead, it is funneled toward residential foundations. This urban runoff often overwhelms older municipal storm sewers, causing water to back up into private properties. This is why having a properly sized and functioning sump pump is no longer just a “nice-to-have” feature for Toronto homeowners; it is a critical line of defense against the changing local climate and urban landscape.
Sump Pump Maintenance Checklist for GTA Homeowners
To prevent emergency failures, follow this seasonal maintenance schedule:
1.The Bucket Test (Every 3 Months): Pour at least 20 litres (about 5 gallons) of water into the pit. Observe the vertical float or tethered switch to ensure it rises freely without catching on the basin walls. The pump should engage smoothly and evacuate the water within seconds.
2.Clear the Intake Screen and Impeller: Over time, the bottom of your sump pit can accumulate “fines”—tiny particles of silt and gravel. These can clog the intake screen at the base of the pump. Periodically disconnect the power and clear away any debris to ensure the impeller can spin at maximum efficiency.
3.Inspect the Discharge Outlet and Air Gap: Trace your discharge pipe to where it exits the house. Ensure the water is directed at least 3 metres (10 feet) away from the foundation, preferably toward a French drain or a lower part of the yard. In the winter, ensure there is an air gap or a “freeze guard” (like the IceGuard system) to allow water to escape even if the main line is frozen solid.
4.Test the Battery Backup System: If you have a backup pump, unplug the primary pump and repeat the bucket test. The backup should trigger immediately. Check the battery terminals for corrosion and ensure the “status” light on the controller is green. Most deep-cycle batteries used in these systems need replacement every 3 to 5 years.
5.Listen for the “Check Valve Hammer”: A healthy check valve makes a distinct “clunk” or “thump” sound when the pump cycles off. This is the sound of the internal flapper closing to prevent backflow. If you hear a loud, metallic banging, you may need a “quiet check valve” to prevent water hammer, which can eventually crack PVC joints.
When to Call Select Plumbing
While a stuck float can sometimes be fixed with a quick adjustment, most “constant run” issues require professional intervention. If you notice any of the following, it is time to call in the experts:
•The pump is hot to the touch or smells like burning plastic.
•There are strange grinding or rattling noises coming from the pit.
•The pump is running, but the water level is rising.
•Your basement has a persistent damp or musty odor.
Frequently Asked Questions (FAQs)
1. Why is my sump pump running when it hasn’t rained?
This is often caused by a high groundwater table or a stuck float switch. In the GTA, clay soil can hold water for days after a storm, keeping the pump active. However, it could also indicate a leaking water main or a broken underground sprinkler line near your foundation.
2. Can a sump pump burn out from running too much?
Yes. Sump pumps are designed for intermittent operation. Running continuously causes the motor to overheat, which can melt internal seals and lead to total mechanical failure. If your pump has been running for more than 6 hours without a break, it is at high risk of burnout.
3. How long should a sump pump last in Toronto?
On average, a high-quality sump pump in the GTA lasts 7 to 10 years. Factors like the frequency of use (high in flood-prone areas like Etobicoke) and the presence of mineral-heavy water can shorten this lifespan. Regular maintenance can extend it toward the 10-year mark.
4. Is it normal for my sump pump to run every 30 seconds?
No, this is known as short-cycling. It is usually caused by a failed check valve allowing water to flow back into the pit or a sump basin that is too small for the volume of water entering. This puts extreme strain on the motor and should be repaired immediately.
5. Does the City of Toronto offer a rebate for sump pump repairs?
The City of Toronto provides subsidies for the installation of new sump pumps and backup systems, but typically not for basic repairs. However, if your current pump is failing, replacing it with a new, eligible system through the Basement Flooding Protection Subsidy Program can save you up to $1,750.
Protect Your Basement with Anta Plumbing
Don’t wait for a flooded basement to take action. If your sump pump is acting up, the team at Select Plumbing is here to help. Serving Toronto and the entire GTA for over 25 years, we specialize in sump pump installation, maintenance, and emergency repairs. We are fully licensed to help you qualify for the City of Toronto Basement Flooding Protection Subsidy.
Contact or visit us online at https://www.selectplumbingandheating.ca/ to schedule your inspection!
