Sump pump installation and replacement

A sump pump is the least glamorous appliance in your house and the one most likely to decide whether you lose a finished basement. It sits in a pit at the low point of the floor, collects groundwater arriving through the weeping tile, and lifts it out and away. It runs hardest during the spring melt and during summer downpours, which are also the moments the power is least reliable.

Step one: work out what you actually need. A good quote starts with questions, not a model number. How deep is the pit, how high does the water have to be lifted, how long is the horizontal discharge run, how often does the existing pump cycle during a wet week. Those numbers set the head the pump has to work against, and a pump chosen without them is a guess.

Step two: the pit. An existing pit is inspected for depth, diameter and whether it is a proper lined pit or a hole in the slab. A new pit means saw-cutting the slab, excavating, setting a perforated liner in clear stone so water can enter from the surrounding soil, and repouring the floor. A pit that is too shallow makes the pump short-cycle and shortens its life.

Step three: the pump itself. Submersible pumps sit in the water and are quieter. Pedestal pumps keep the motor above the pit and are easier to service. Cast iron bodies shed heat better than plastic and generally last longer. The float switch is the component that most often fails, so a solid vertical float or a tethered switch with room to swing beats a cheap piggyback switch.

Step four: the discharge. A check valve above the pump stops water in the pipe running back into the pit every cycle. The line leaves the house and discharges well clear of the foundation, not beside it and not onto a neighbour's property. In Ottawa the outdoor section needs to be freeze-resistant, with a slope that drains and an outlet that will not be buried in a snowbank in February.

Step five: the backup, which is the real decision. A battery backup pump is a second pump in the same pit on its own float, powered by a deep-cycle battery that charges off mains power. When the power fails, it takes over. Run times are usually quoted in hours of continuous pumping and vary with battery size and lift. Water-powered backups use municipal water pressure and run indefinitely, though they consume water and are not permitted everywhere. A high-water alarm is cheap and worth having whatever else you fit.

How long it takes. A pump swap in an existing pit is one to three hours. A new pit with a pump is usually a full day, plus concrete cure time. Adding a battery backup to an existing installation is typically half a day, less if an electrician is not required.

What it costs in Ottawa in 2026, and the City subsidy. Indicative ranges, matching this site's price guide: a pump replacement in an existing pit generally runs $600 to $1,400, and a new sump pit with a pump $1,500 to $3,500. A battery backup adds to both. The subsidy is the number worth planning around. The Residential Protective Plumbing Program pays $3,000 toward a sump pump installed in a new pit and $1,500 toward one in an existing pit, plus 100 per cent of the building permit fee (City of Ottawa). Eligibility depends on when the house was built, it covers new installations rather than like-for-like replacements, the work must be done by a licensed plumbing contractor under a permit, and there is a deadline for applying after the permit is issued. Check the current terms at ottawa.ca/rppp first. What moves the contractor's price: whether a pit exists, slab depth, the discharge run, whether electrical work is needed, and which backup you choose.

What makes an Ottawa house different. Champlain Sea clay drains badly, which is why sump pits are close to standard in the suburbs built on it, from Barrhaven and Riverside South to Stittsville and Half Moon Bay. The other local reality is the melt. Ottawa can go from a metre of snowpack to saturated ground in a fortnight, and a pump that coped all winter can run near-continuously for three weeks in March. Freezing rain and summer thunderstorms both take the power out here, which is the plain argument for a backup: the pump is needed most in exactly the conditions that cut its supply. Check the outdoor discharge in a January thaw, because a frozen outlet makes the pump run against a closed pipe.

Who should do the work. Plumber is a compulsory trade in Ontario, so the plumbing connections need someone holding a current Certificate of Qualification, checkable on the Skilled Trades Ontario public register. A dedicated circuit for the pump is electrical work and belongs to a licensed electrical contractor, with an Electrical Safety Authority notification. The City's subsidy requires a licensed plumbing contractor, so an unpermitted cash job forfeits both the inspection and the money.

What to ask before you hire. What head and flow did you calculate, and what pump does that call for. Cast iron or plastic, and what switch type. Is a check valve included and is it a quiet one. Where does the discharge terminate and how is it protected from freezing. Which backup, what run time, and what battery maintenance does it need. Is a high-water alarm included. Are you pulling the permit and handling the rebate paperwork. What is the warranty on the pump and on the labour.