Sump Pump Not Working: The October Test and Every Failure You Can Catch First

The Honest Answer Up Front

When a sump pump "is not working," one of five things is true, and four of them are catchable in October with a bucket and a flashlight. The pump has no power — the outlet, the breaker, the GFCI that tripped in September when nobody was looking. The float switch has failed or jammed — the single most common dead-pump cause we find, and the one the bucket test catches in ten seconds. The pump runs but moves no water — impeller jammed with gravel, check valve failed, or discharge blocked. The pump runs constantly — stuck float, check-valve leak-back, or a basin that is genuinely receiving more water than the pump can shed. Or the pump is fine and the water is arriving somewhere the pit cannot see — the crawlspace low spot, the crack the previous owner caulked hopefully.

The geography matters more than most guides admit, because our region splits the sump world in two. In the high-water-table, peat-soil municipalities — Richmond, Delta, Pitt Meadows, the flat stripes of Surrey, parts of Burnaby's low reaches — the sump is a permanent organ of the house, cycling through storm weeks, and its failure mode is a wet floor within hours of heavy rain. In the hillside and valley communities, the sump is episodic — it may sit silent for months, then run all night during an atmospheric river — and its failure mode is the silent one: the homeowner who assumes no news is good news and discovers in November that the pump died in March. The test habit is the answer to both, which is why this guide's first commandment is dated: test in October, before the rains, every year.

The economics run short: the test is free, the alarm that makes it redundant is about forty dollars, most repairs — switch replacements, check valves, discharge fixes — land in the $180 to $650 band, and a full replacement sits in the $650 to $1,400 installed range our installation guide itemizes. The comparison that makes those numbers feel small: the pump is the only thing standing between the water table and everything you keep at floor level, and the households that replace pumps on a schedule — rather than on a crisis — are the households whose basements stay stories instead of claims. The plumbing crews who work the flood districts keep those schedules for their own houses, which tells you the whole thing.

How the Whole System Works (Pit, Float, Valve, Discharge)

The sump system is four parts wearing a pump costume. The basin — that plastic or concrete cylinder set into the lowest floor — collects the water that arrives from the perimeter drains, the weeping tile, or simply the ground under the slab, and it is sized so that water accumulates somewhere harmless. The float — a switch on a tether, a vertical rod, or a diaphragm — watches the water level and closes the circuit that starts the pump. The pump itself moves the water up and out. And the discharge assembly — pipe, check valve, and the run to a legal disposal point — carries it away from the foundation. Every failure in this guide is a failure of one of these four, and the troubleshooting sequence is just an inspection of them in order.

The check valve deserves a paragraph because it explains a sound every sump owner knows: the clunk at pump shutoff. The valve is a one-way gate in the vertical discharge that stops the lifted water from falling back into the basin when the pump stops — without it, every cycle would re-drop its column of water and the pump would run twice for one volume. The clunk at shutdown is the valve closing, and it is normal. What is not normal: rapid double-cycling — pump runs, stops, immediately runs again — which is the signature of a check valve leaking back and the column re-dropping into the basin, or a float set so close to the on-level that the returning water retrips it.

The discharge run is the outdoor half and the winter half. Water leaving your house needs a destination that is away from the foundation, on your property or into a permitted connection — many municipalities have rules about sum discharge to the storm system, and the 1990s-and-earlier habit of tying it to the sanitary sewer is now a cross-connection problem in most of the region. The winter risk is freeze-up: a shallow above-ground run that exits a wall and travels along grade will ice over in an arctic-outflow snap, the pump will run against a blocked line, and the basin will overflow exactly when it is coldest. Buried runs below frost depth, or a steep, short, well-drained exit are the standard answers, and valley communities from Maple Ridge out to Chilliwack see the freeze version every cold snap.

The October Test: Thirty Seconds, Once a Year

Here is the whole ceremony, timed. Unplug the pump, plug it back in — you should hear or feel it attempt a start for a moment; if the outlet is dead or the breaker is off, you have found your first failure and it was free to find. Pour ten litres of water into the basin — a bucket, poured at a walking pace. Watch the float rise with the water. The pump should start before the water nears the rim, run smooth and unlaboured, empty the basin to the shutoff level, and stop — all within thirty seconds to a minute. Listen at the end for the single healthy clunk of the check valve. That is the entire test, and it is worth more than a decade of assuming.

What each deviation means, in the order you would notice it. Pump does not start: outlet or breaker (test with something else — a phone charger — before blaming the pump), then the float switch (lift it by hand — if the pump starts, the switch mechanism is the problem, jammed, tangled, or dead), then the pump itself. Pump starts but the water does not drop: check valve failed closed (rare but real), impeller jammed with gravel or debris — a submersible pulled from the basin and inspected by eye — or a blocked discharge line, which you trace with your ears, since a pump pushing against a blockage sounds laboured, sometimes rattly, and cycles on thermal overload if you let it struggle. Pump runs constantly and never shuts off: stuck float, leak-back through the check valve, a continuous inflow the pump cannot outpace, or — the honest one — a basin with a perpetual water source that needs a bigger conversation about drainage.

October specifically, and not "whenever," because the calendar is the whole trick. The pump that dies in March is discovered in November if nobody tested; the pump that dies in October is discovered in October, in dry weather, with a week to schedule a replacement at a civil pace. Every plumber in the region knows the first-week-of-November scramble — the atmospheric-river forecast drops, and every marginal pump in Richmond and Delta becomes an emergency in the same 48 hours. The test habit is how your house skips that queue entirely. And while you are in the crawlspace anyway: the winter prep guide has the rest of the seasonal list.

Float Switches: The Number One Dead-Pump Cause

The float switch is the pump's only sense organ, and it fails in ways that all look like "pump not working" from the living room. Tethered floats — the bulb on a cord — tangle against the basin wall or the discharge pipe, so the water rises past the switch's reach and the pump never learns it is needed. Vertical-action floats — the guided float on a rod — jam on their rod when silt or scale crusts the track, with the same silent result. Diaphragm switches — the pressure-sensing kind on some submersibles — clog or fatigue and drift, cycling the pump at the wrong levels or not at all. And every switch type simply dies electrically, from decades of arcing its little contacts on and off, ten seconds at a time.

The fingerprints separate the modes without tools. Pump never starts but runs perfectly when you lift the float by hand: the switch is jammed or tangled — sometimes fixable by repositioning or untangling, sometimes the switch is simply finished. Pump cycles at the wrong water level — starting when the basin is nearly dry, or barely stopping before overflow: switch drift or debris on the track. Pump that hums with water over the switch: power is reaching the motor, and the problem is downstream — impeller, check valve, or the sad end of the motor itself. The hand test in the previous chapter is the diagnosis: the float that starts the pump by hand has told you the pump lives and the switch does not.

The repair economics are friendly. Many quality pumps have replaceable switch assemblies — a fraction-of-the-pump cost repair that our plumbers carry on the truck for the common makes. On pumps where the switch is integral, the honest conversation is age-weighted: a switch replacement on a six-year-old pump makes sense; the same repair on a twelve-year-old pump is tribute paid to a machine about to fail on a different part, and the $650-to-$1,400 installed replacement range — new pump, basin inspection, check valve, discharge review — is the wiser spend. The sump installation guide breaks that band down by what is included, and the honest version of our advice is that pumps, like alarms, get replaced on schedules, not on failures.

Check Valves, Clunks and the Mystery of the Double-Cycling Pump

The check valve earns its own chapter because it causes three different phone calls. Call one: "the pump makes a loud clunk." Almost always the check valve doing its job — the column of discharge water dropping onto the closed valve after shutoff. If the clunk is objectionable, a quieter-design valve or a small air chamber quiets it; if the clunk is new and accompanied by weak emptying, the valve may be partially obstructed. Call two: "the pump runs twice for every cycle" — the classic leak-back signature. The valve is not sealing, the lifted column re-drops into the basin, the float retrips, and the pump runs again; the pump is being asked to lift the same water two or three times, which doubles the wear and halves the margin on stormy nights.

Call three is the subtle one: "the pump runs for a second every few minutes, forever." Micro-cycling has a short suspect list: a leak-back check valve combined with a float set just above the re-trip level; a pit so narrow that the returning column alone retrips the switch; or a genuinely continuous inflow — a high water table, a leaking service, perimeter drains delivering a trickle — that the basin absorbs and the pump shaves off in slivers. The diagnosis separates them: watch the water level between cycles. Rising with no rain and no fixtures running is inflow; falling then bumping back up at the same rhythm as the clunk is leak-back.

The repairs are among the most satisfying in plumbing because they are cheap relative to the anxiety: a check valve replacement is a same-visit repair in the $180 to $650 band, lower half in an accessible pit; a float adjustment or a switch replacement similarly modest; and a basin that is genuinely too small or a pit configuration that micro-cycles gets the honest conversation about a proper pit — which the installation guide covers as part of the new-pit versus pump-swap chapter, the fork that decides where in the $650-to-$1,400 installed range a project lands.

Power Failures: The January Stakes

Here is the uncomfortable meteorological fact that organizes this chapter: the storms that load your sump are the same storms that knock out power. An atmospheric river arrives, the water table climbs, the outage hits a neighbourhood, and every electric-only sump pump in the district stops exactly when the water starts. The failure is not the pump — the pump is fine, dark and useless. The January stakes, as our emergency crews can attest, are measured in basements that flooded during outages with pumps in perfect working order.

The backup options, compared honestly. Battery backup systems: a 12-volt deep-cycle battery driving a secondary DC pump mounted above the primary, with a charger-alarms that keeps the battery ready and screams when it takes over — the common retrofit, installed in the $1,000-and-up range depending on amp-hours and whether it is paired with a new primary; capacity is measured in hours-of-pumping against a rain event, and the honest sizing conversation is about your water table, not the brochure's. Water-powered backup: a venturi pump driven by municipal water pressure that has no battery to die, runs as long as the city has pressure, and is gloriously simple — with the costs and code caveats: it uses potable water to move groundwater, needs a pressure check, and requires a backflow-prevention conversation on the supply connection; some jurisdictions view them less favourably than others.

The simpler layers that every sump household should have regardless: a high-water alarm — float-mounted or a WiFi water sensor near the pit, forty dollars, and the single cheapest early-warning in plumbing — and generator households with a transfer setup that includes the sump circuit on its priority list. During the outage years that punctuated our region's recent history, the households that stayed dry were disproportionately the ones with an alarm, a battery layer, or a generator plug in the crawlspace. The pump is the soldier; the power question is whether the soldier is awake. And for the night the water wins anyway, the first-sixty-minutes guide covers the shutoff-and-triage sequence that applies to every flooding event, pipe or pit.

Pedestal versus Submersible, and the Replacement Clock

The two pump architectures have honest personalities. Pedestal pumps — motor on a column above the pit, switch on a float rod, cooling by air — are the serviceable classic: the motor sits in crawlspace air where it can be seen, heard and worked on, the price is gentler, and the lifespan under light duty runs long. Their costs: they live where the noise lives, they need the pit open or a vented lid, and they are the wrong tool for finished spaces or heavy continuous duty. Submersibles — motor sealed in the housing, sitting in the water — are the modern standard: quieter, sealed against the silt that kills open motors, able to run hot cycles in deep or busy pits, and available in the cast-iron, higher-head duty versions that flood-risk homes deserve.

The replacement clock, stated without euphemism. Pedestal pumps in light duty: five to eight years common. Quality submersibles in moderate duty: eight to twelve. Heavy-duty cycles — the Richmond and Delta pits that run all storm season — consume pumps faster, and the honest households in those districts treat eight years as the replacement horizon and the float-switch replacement as a mid-life event. The clock also runs on the non-pump parts: the basin cracks, the lid seals and vents age, the discharge pipe and its fittings corrode at the exposed joints, and the electrical circuit — GFCI, breaker, the outlet itself — ages in damp air. A sump system that is twenty years old end-to-end is a system whose every part is on borrowed time simultaneously.

The replacement math, from the installation guide's numbers: a pump swap — new pump, new check valve, basin inspection, discharge review — lands toward the lower end of the $650-to-$1,400 installed band; a full new pit — excavation, basin, gravel bed, lid, pump, discharge to code — occupies the upper end and is the correct project for the house whose pit is undersized, cracked, or receiving more water than its geometry can buffer. What we tell every flood-risk household in October terms: replace the pump when the calendar says so, not when the water says so, because the calendar version is scheduled, quoted in dry weather, and boring — which is the goal.

The Discharge Line: Freezes, Loops and the Neighbour's Lawn

The discharge run is where good pumps go to be defeated. The freeze failure: a shallow run, or an exit that drains onto a flat grade, ices over in the first arctic outflow, and the pump pushes against a blockage until the basin overflows or the thermal overload protects the motor by shutting it down — the pump did its job; the pipe did not. The geography of the freeze version is the valley and outflow-exposed communities: Maple Ridge, Mission, Abbotsford, Chilliwack see it every cold snap, and the fixes are standard — buried runs below frost depth, insulated above-grade sections, a steep short exit that drains fully after each cycle, and a weep hole positioned so the vertical column never holds water at the freezing stretch.

The drainage failure: the exit that dumps its water against the foundation — the pump's output re-entering the ground it just evacuated, a loop that keeps the pit cycling and the soil saturated. Every metre of discharge should carry water away: onto a grade that sheds it, into a splash block or a stone bed that spreads it, or into the storm connections your municipality permits. The related courtesy rules matter more than they look: discharge onto a shared lane, a neighbour's property line, or a sidewalk that ices over in January creates the interpersonal version of a plumbing failure, and most municipalities have bylaw language about sum discharge destinations that is worth a ten-minute check.

The maintenance rhythm for the whole outdoor half: walk the run once in October — trace it from the pit to the exit, look for sagging sections that hold water, crushed pipe under a new deck planter, joints separated by frost heave, and the erosion channel at the exit that is quietly routing water back to your wall. Then walk it once mid-winter during the first real cold stretch, looking for the ice dam where the run meets the grade. Ten minutes twice a year, and the discharge half of the system stops being the half that fails — and the $199 annual maintenance plan exists to put exactly these walks on a calendar besides your memory's.

The Basin: Silt, Gravel and the Quiet Fill-Up

The pit itself needs maintenance, which surprises homeowners who assumed the basin was infrastructure rather than equipment. Every pit collects what the water carries: silt, fine sand, the gravel that migrated from the original bed, the occasional construction fastener from a decade of work above. An inch of accumulated sediment is normal; six inches is a problem with a schedule — it breeds the impeller jams, it buries the pump's cooling surfaces, it gives microbes a dark wet theatre for the smell stories, and on the switch side, it crusts float rods and fouls diaphragms.

The cleanout is an honest piece of work rather than a chore: power off and locked, pump lifted out (this is the moment the check valve and the pipe condition get their inspection), the standing water and sediment bailed or vacuumed, the basin walls scrubbed, the bed replenished with clean washed stone to support the pump and keep it out of the silt, and the pump re-seated, re-tested with the bucket pour, and the date written on the lid. In high-silt districts — the peat and sand pockets of Richmond and Delta especially — the cadence runs one to three years, and it is the single most neglected maintenance item we find on sump calls, which is a polite way of saying most basins in the region have never been cleaned. The neglected basin also connects to the smell catalogue in the sewer smell guide, because a fouled pit is a biological event as much as a mechanical one.

The basin review is also when configuration problems surface: the undersized pit that cycles constantly because it holds one pour's worth of water; the lidless pit in a crawlspace where radon and humidity conversations live; the pit with the weeping tile dumping directly at the pump intake, silt express-delivered; and the two-pump households — primary and battery backup — whose floats must be staggered in elevation so they do not compete. All of these are correctable, all of them are quotable, and none of them get better on their own — the basin is patient and the water is not.

Sizing: Horsepower, Head and Gallons

Pump sizing is three numbers and none of them is marketing horsepower. The flow requirement: how many litres per minute arrive at the basin in a serious rain event — measured, in a perfect world, by timing the basin fill during a storm, or estimated from the perimeter-drainage area and the district's water table story. The head: the vertical lift from the basin's low-water line to the discharge exit, plus the friction losses of the horizontal run and its fittings — every elbow is a tax. And the duty: continuous versus intermittent cycling, which determines the class of motor you buy. A 1/3-horsepower submersible handles the modest pits of most hillside homes; the heavy clay-and-peat districts and the deep basins of finished homes justify 1/2-horsepower and cast-iron duty pumps with the head curves to match.

The undersizing symptoms are recognizable in hindsight: a pump that runs continuously through storm events and barely holds the water level; a basin that wins slowly during atmospheric rivers; a pump that cycles so frequently in the wet season that its replacement clock sprints. The oversizing symptoms are subtler and cheaper: short brutal cycles that empty a small basin in two seconds — hard on switches and check valves — and the classic micro-cycling rhythm from the check-valve chapter. The right answer is matched, not maximal: the pump that meets the measured flow at the actual head with duty to spare.

The homeowner's sizing contribution is data, not dollars: know your pit's diameter and depth, the lift height to the exit, the length of the discharge run, and — gold — the fill-time of your basin during real rain, timed with a watch and written on the lid next to the test dates. That four-line profile turns any future pump purchase or quote into arithmetic instead of aspiration, and it is the difference between the pump you needed and the pump that was on the shelf.

When to Stop Repairing and Replace

The verdict framework, in the order it runs in the field. Age past the clock: pedestal past eight, submersible past twelve — replace on schedule, especially in flood-risk homes, because the calendar version of replacement is a planned Tuesday and the failure version is a November night. Any motor failure on an older pump: hums-but-doesn't-turn, trips the breaker, runs hot and smells like a projector — the motor is the pump, and motor money on an aged unit is tribute. Repairs stacking: the second or third switch, valve or float repair on the same pump within a few years is the pump voting for retirement. And the configuration verdicts: the undersized basin, the exhausted discharge, the pit that receives more than any pump should be asked to lift — these are system replacements wearing a pump-shaped costume.

What replacement includes, so the quote reads as value rather than surprise: the pump matched to the measured duty; the check valve renewed; the basin inspected and cleaned while the pit is open; the float geometry set and tested with the bucket pour before we leave; the discharge walked to its exit; the electrical — outlet, GFCI, breaker — verified; and the date written down, by us, as part of the handover. In the $650-to-$1,400 installed band from the installation guide, the swap-with-checks lands low and the full new-pit project lands high, and the difference between them is your existing basin earning its keep.

The pairing question that ends this chapter: replace the pump, add the backup, or both. The flood-risk districts answer it with "both, on a schedule" — primary replaced at the clock, battery backup layer added when the household math includes a finished basement, a suite, or an outage memory. The episodic districts can reasonably run the primary alone with the forty-dollar alarm as the tripwire. Both districts answer "replace before it fails" when the alternative is spelled out, and our plumbers write those recommendations with the calendar visible — October install, dry November, boring forever after.

What It All Costs and the October Checklist

The ladder, priced honestly. Tonight's test: free, thirty seconds, ten litres. The alarm: about forty dollars for a high-water float alarm or WiFi sensor, installed by you in minutes. The maintenance cleanout: part of a service visit, and part of the $189 deep-service tier when bundled with the rest of the mechanical once-over. Repairs — switch replacements, check valves, float adjustments, discharge fixes: the $180 to $650 band, with the $89 diagnostic credited to any completed repair. Replacement: $650 to $1,400 installed, per the installation guide's itemization. Battery backup layers and generator circuits: quoted project work. After-hours calls: one flat $150 premium, disclosed before the truck rolls — and storm-week emergency calls are exactly what it exists for.

The response map, for the night it matters: 30 to 45 minutes typical in Vancouver, Burnaby, Richmond, New Westminster, North Vancouver and Port Coquitlam; 45 to 60 minutes in Surrey, Coquitlam, Langley and Delta; 50 to 85 minutes for the valley communities. The 24/7 line at 604-615-2212 is answered by a live dispatcher who will ask whether the water is rising with the pump running — because that answer routes the call as capacity-emergency rather than pump-repair, and both trucks are different.

And the closing picture this guide wants to leave: a Richmond crawlspace in late October, ten litres of water poured at a walking pace, the float rising freely, the pump starting briskly, the basin emptying, one healthy clunk, the date written on the lid. Thirty seconds, once a year, in the last dry weeks — that is the entire distance between a sump pump that works and a sump pump you know works. In the districts where the water table votes on your basement, that knowledge is the cheapest flood insurance on the market, and it renews every October for free.

Sump symptoms at a glance — what each means and what it costs to fix.