Sump pumps and battery backups
The pump is the one part of a waterproofing system that has to work at 3 a.m. in a storm with the power out. We size it for the water your house actually gets, give it a proper pit, and back it up with a battery.
- Wherethe lowest corner
- Seasonany
- Timehalf a day to a day
- Includespit, pump, valve, discharge
In section
What a proper installation has
- A lined pit, sized for the inflowA perforated liner set in stone below the slab, deep enough that the pump does not short-cycle. A bucket in a hole is not a pit.
- Pump on a base, float swinging freeRaised off the silt, with room for the float to rise and fall without touching the wall of the pit, which is the most common cause of a pump that "just stopped".
- Check valve, then outStops the column of water in the discharge line falling back into the pit every cycle.
- Battery backupA second pump on its own float and a deep-cycle battery, which takes over when the power fails or the main pump does.
The discharge
Where the water goes matters as much as the pump
A pump that discharges beside the foundation is pumping the same water in a circle. The line should run at least three metres from the wall onto ground that falls away, or to a dry well on a flat lot. On a lakeshore lot the discharge cannot go toward the lake without the conservation authority's say, and on a well-and-septic lot it cannot land on the bed or near the casing.
Winter adds one more rule: the line must drain empty after each cycle, or it freezes, the pump runs against a closed pipe and burns out. We slope the line and use a freeze relief fitting where the run is long.
Pump older than seven years, or never tested? Book a check and we will run it under load.
Book a free assessmentQuestions
About pumps
How often does a sump pump need replacing?
Manufacturers rate residential pumps at roughly seven to ten years of normal use, but on a wet lot a pump can cycle thousands of times a season and wear out sooner. Lift the lid twice a year and pour a bucket of water in: the float should rise, the pump should run and the pit should empty. If it hums without pumping, cycles constantly or has never run in your ownership, it is due.
What happens to the sump pump when the power goes out?
It stops, and in a storm that is exactly when the pit fills fastest. A battery backup pump sits in the same pit on its own float and takes over automatically; a good one runs for several hours of steady pumping. For a house on a well and septic that already loses water in an outage, we treat the backup as part of the pump installation, not an extra.
We are on a well and septic. Does that change anything?
Yes, two things. Before any excavation we locate the septic bed and lines, the well casing and its water line, so the machine never goes near them. And the discharge from a sump has to go somewhere that is not the septic bed and not back at the well head, which on a small lot takes some thought. Many houses in the township are on private services, so this is routine for us, but it has to be planned, not discovered.