If your Lower Mainland home has a finished basement and a sump pump, the cost of doing this wrong is measured in tens of thousands of dollars of flood damage. We get the panicked midnight calls every storm season — power out, sump pump dead, water rising. Almost every one of those calls could have been prevented by a $400–800 battery backup install during the dry months. Here's how to think through the sump-pump system for your specific Lower Mainland home.
How a sump pump system actually works
A sump system has four parts working together:
- Sump pit — a hole cut into the lowest part of the basement floor, lined with a perforated basin
- Primary pump — submersible or pedestal pump that activates when the pit fills
- Discharge line — pipe that carries the pumped water away from the foundation
- Float switch — a sensor that turns the pump on at a high water level and off when the pit empties
Optional but increasingly standard in Lower Mainland homes:
- Battery backup pump — secondary pump that runs on a deep-cycle battery when grid power is out
- High-water alarm — float-triggered audible/SMS alarm if the primary fails
- Check valve on the discharge line — prevents pumped water from flowing back into the pit
Primary pump — what to look for
Submersible vs pedestal
Submersible pumps sit at the bottom of the pit, fully underwater. They run quieter, last longer, and handle small solids better. Pedestal pumps have the motor above the pit on a vertical shaft — cheaper, easier to service, but noisier and less durable. We almost always install submersible for Lower Mainland homes. The cost difference is small and the longevity difference is large.
Cast iron vs plastic housing
Cast-iron submersibles dissipate heat better, last longer under heavy duty cycle, and are quieter. Plastic-housing pumps are cheaper but tend to fail sooner under the heavy seasonal duty Lower Mainland basements demand. For the price difference (~$50–100), cast iron is almost always the right call.
Horsepower / capacity
Most residential basements are well-served by a 1/3 HP or 1/2 HP submersible. 1/3 HP moves ~2,500–3,500 gallons per hour at typical residential discharge head; 1/2 HP moves ~4,000–5,000 GPH. If you have a high water table, a deep basement, or long discharge run, step up to 1/2 HP. For most Surrey, Newton, Cloverdale, and South Vancouver basements, 1/3 HP is adequate.
Float switch type
Three options, ranked by reliability:
- Vertical float (electronic switch on a vertical rod) — most reliable, no moving tether to get hung up. Our preference.
- Tethered float (the classic ball-on-a-cord) — cheap and proven, but can get caught on the pit wall or pump body and fail to trigger
- Diaphragm pressure switch — sealed, no moving float, but more expensive and harder to diagnose when issues arise
Battery backup — the system that saves the day
Here's the thing most homeowners miss: severe storms cause both heavy rainfall AND power outages, and they're often correlated. When the lights go out, the sump pump goes out too — at the exact moment it's most needed. A battery backup pump runs entirely off a deep-cycle marine battery and can pump for 4–12 hours depending on battery capacity and pump cycle frequency.
Backup pump options
- DC-powered backup pump (e.g. Zoeller Aquanot, Wayne ESP25) — runs off a 12V marine battery, integrated controller, audible alarm, 4–8 hour runtime under load. Our default recommendation.
- Water-powered backup pump — uses municipal water pressure to drive an ejector pump. No battery to maintain. Wastes water 1:1 with what it pumps. Less common in Lower Mainland.
- Generator-fed primary — if you have a whole-house generator, the primary pump runs through outages. Premium solution but rare.
Battery selection
A backup pump is only as good as its battery. Use a deep-cycle marine battery (NOT a car starting battery). Group 27 or 31 sized AGM (sealed lead-acid) batteries are common, with ratings around 100Ah. AGM batteries can be installed indoors without ventilation concerns (unlike flooded lead-acid). Expect to replace the battery every 4–6 years.
Discharge line — where the water goes matters
Three rules:
- Discharge at least 6 feet from the foundation — closer than that and you're just recirculating water back into the pit
- Don't connect the discharge to your sanitary sewer in the Lower Mainland — most municipalities prohibit this (it overloads the sewer system during storms)
- Use rigid PVC for the indoor section and either a flexible hose or buried PVC for the outdoor run. Don't use corrugated drain pipe — it kinks and freezes
Cold-snap consideration: any above-ground discharge line in the Lower Mainland will freeze in a sustained cold snap if it doesn't have a freeze-protection feature. Most modern installs include a 'freeze guard' or pressure-relief fitting that allows the pump to discharge to the basement floor if the outdoor line freezes — preventing pump burnout. Worth specifying on any new install.
Annual maintenance — 15 minutes saves the basement
Once a year, ideally in October before storm season:
- Pour a 5-gallon bucket of water into the sump pit — confirm the primary pump kicks on and empties the pit
- Listen for unusual noises (grinding, intermittent humming) — early sign of bearing failure
- Check the float for free movement — make sure no debris is fouling it
- Inspect the discharge line for leaks, kinks, or freeze damage
- Check the battery voltage on the backup system — should read 12.5–13V resting; if lower, replace
- Press the test button on the backup-pump controller if it has one — verify alarm works
We offer pre-storm-season service calls in the Lower Mainland — typically October through November — at a flat rate that's well under the price of a flooded basement.
How long do sump pumps actually last?
Primary submersible pump: 7–10 years typical, longer if it's lightly used, shorter if it cycles dozens of times a day. Battery backup pumps last longer because they're rarely used — but the BATTERY needs replacing every 4–6 years regardless of usage. We recommend replacing the primary at year 7–8 proactively, before it fails.
Frequently asked
Do I need a backup if I have a generator?
Maybe not — if the generator reliably picks up your house's electrical load and the primary pump is on a circuit included in the transfer. Worth verifying that pre-storm. If the generator only powers select circuits and the sump isn't one of them, you still need the backup.
Can I install a sump pump myself?
If a sump pit and discharge line already exist, replacing a primary pump is a doable DIY job. Installing a sump system from scratch (cutting concrete, routing discharge, electrical) usually isn't.
How much does a backup system cost?
Hardware costs vary by brand and capacity but typical residential backup systems run a few hundred dollars in equipment plus install labour. We give honest line-item quotes on every install — call for a free on-site assessment.
Got the problem we just described? We answer 24/7 across Surrey, Langley, Vancouver, Burnaby, Coquitlam, Delta, White Rock, and Richmond. Call Mr. Plunger Plumbing & Drainage at (604) 870-1442 — real plumber on the line, exact ETA before dispatch, up-front quote before any work starts.