Sump pump won't run (or won't stop)

Q: Sump pump won't run (or won't stop)

In Canada, when a sump pump won't run, the first thing to rule out is power — a bumped plug, a tripped GFCI outlet, or a tripped breaker — followed by a float switch stuck against the pit wall. A pump that hums but moves no water usually has a jammed impeller or a frozen or blocked discharge line. A pump that never shuts off is often a float stuck in the "on" position or a failed check valve. If water is rising in the pit or on the floor right now, do not reach into or touch the pump while standing in water — that is a shock risk — and call a licensed plumber.

A silent or non-stop sump pump is unnerving, but the fix is often free — a bumped plug, a stuck float, or a bit of debris — as long as the pit isn't actively flooding.

tuneWhat are you noticing?

Select anything that matches and the checklist below reorders to fit. Not sure? Skip it.

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Start here

In Canadian homes, check power first. Confirm the pump is plugged in fully, press the RESET button on the GFCI outlet it feeds from, and check the breaker panel for a tripped breaker on that circuit. This is free and the single most common reason a pump goes silent. If the GFCI or breaker trips again the moment you reset it, stop — that's the pump's wiring protecting you — and call a plumber or electrician.

Ranked from real-world failure data. The order updates as you select what you’re noticing above.

Likely causes, in the order to check them

Showing the typical order

Beginner-friendly Doable, with care Safety-critical Call a pro

handymanHow to fix it

Unplug the pump, free the float and clear anything jamming it, and reposition the pump so the float can swing without hitting the pit wall or cord; if the switch itself is worn, replace the float switch with a matching type.

Unplug the pump before reaching into the pit.
Free the float, untangle it from the cord, and remove any debris. Reposition the pump so the float has clear room to rise and fall.
If the float or its switch is cracked, waterlogged, or won't actuate, fit a matching replacement float switch (tethered or vertical to suit the pump).
Plug back in, pour in a bucket of water, and confirm the pump starts as the water rises and stops when it drains.

schedule30 min savings$0–40

Sump pump float switchMatch tethered vs vertical style and the pump's plug-in "piggyback" connector or direct-wire type

visibilityHow to check

report Unplug it before you reach inThe pump sits in water and runs on 120 volts. Always pull the plug at the outlet before putting a hand in the pit or lifting the pump — do not rely on the switch or the float being "off." If the outlet is wet or you can't reach the plug without standing in water, stop and treat it as the active-flood case: cut the breaker or call a plumber.

Unplug the pump at the outlet before you touch it — never reach into the pit with the pump still powered.
Lift the pump out of the pit by its handle (not the cord) and set it on a towel. Look at the intake screen and impeller opening on the underside for gravel, silt, or a lodged stone.
Turn the impeller by hand or clear the intake; if it was seized by debris and now spins freely, that was almost certainly the jam. Rinse it, reinstall, and pour in a bucket of water to confirm it pumps.

buildglovesbuildbucket schedule20 min

handymanHow to fix it

With power off, disconnect the discharge union and lift out the old pump, then install a matching submersible sump pump (match horsepower and the discharge pipe size), reconnect the check valve and union, and test with a bucket of water before relying on it.

Unplug the pump (or, for a hardwired unit, switch off its breaker and verify it's dead) before doing anything else.
Loosen the discharge union above the check valve and lift the old pump out by its handle. Note the pipe size and the pump's horsepower for a like-for-like match.
Set the new submersible pump in the pit, reconnect the discharge and check valve, and make sure the float has clear room to swing.
Restore power, pour in a bucket of water, and watch a full on/off cycle: it should start as water rises, empty the pit, and shut off without water draining back.

schedule90 min savings$150–400

Submersible sump pumpMatch the horsepower (commonly 1/3 or 1/2 HP) and the discharge pipe size (usually 1-1/2")

report Water and 120 volts don't mix — kill the power firstA sump pump lives in water and runs on a live 120-volt circuit, so a swap starts with cutting power: unplug it, or for a hardwired unit switch off and verify the breaker is dead, before your hand goes near the pit. Never work on the pump while standing in water. A plug-in pump swap is well within reach for a careful homeowner, but if the pump is hardwired or the outlet looks damaged, hand it to a licensed plumber or electrician.

gavel Check your province first AB: homeowner may do this · BC: homeowner may do this · ON: permit + inspection required · PE: homeowner may do this · QC: licensed professionals only
Replacing a cord-and-plug submersible pump like-for-like is generally owner-permitted; any hardwired connection or new circuit is licensed electrical work — confirm the provincial rule.

sort

Why the list is in this order

We don’t sort by likelihood alone. We sort the way a good, honest tradesperson thinks: rule out the free, safe, common causes first. That’s why the cheap checks outrank the expensive repairs — and why anything dangerous gets a hard stop instead of a pep talk. The order exists to save you money, not to sell you anything.