Sump pump not working? The 3 most common reasons sump pumps fail

A sump pump only matters on the worst day of the year, so it's easy to forget until it stops. These are the three failures we see most in Ottawa basements, and what to do about each.

Black drain pipe and angled elbow exposed beneath timber framing beside a hanging cable.

Filed under Basement Flood Protection · By Michael and the team at The Irish Plumber

First, check the simple things

If your sump pump isn't running and water is rising:

  1. Is it plugged in, and is the outlet live? Check the breaker and any GFCI outlet that may have tripped.
  2. Is the float free? The float can get stuck against the pit wall or tangled in the cord. Move it gently by hand.
  3. Is the discharge line clear? In winter, an outdoor discharge line can freeze solid.

If the pump hums but doesn't move water, or doesn't start at all with power and a free float, it has probably failed. Call a plumber, and keep a wet-dry vacuum or buckets handy.

Reason 1: The pump is overworked

Some pumps are too small for the water that comes in, especially during the spring melt. A small or low-cost pump that runs constantly burns out early. And one pump, however good, can't keep up when the inflow is very heavy.

The fix: a pump sized for your pit and inflow, and in high-water homes a secondary pump that kicks in when the first can't keep up.

Reason 2: A blockage or a stuck switch

Gravel, silt and debris in the pit can jam the impeller or block the intake. Float switches stick, and cords shift. A check valve on the discharge can fail and let water flow back into the pit.

The fix: clean the pit once a year, check the float moves freely, and test the pump by pouring in a bucket of water each spring and fall.

Reason 3: Poor installation, or no power

A pump sitting directly on silt, a discharge line that dumps water back at the foundation, or a missing check valve all shorten a pump's life. And the most common failure of all is simple: the power goes out during a storm.

The fix: a proper install, and a battery backup sump pump that runs when the main pump can't.

Sump pump giving you trouble?

We'll test it, tell you if it's worth repairing, and explain your backup options.

The City may pay part of it

For homes built before 2004, the City of Ottawa rebates up to $1,500 for a sump pump with battery backup in an existing pit, or $3,000 if a new pit is needed. The permit has to come first. See the details.

Questions Ottawa homeowners ask us

How long do sump pumps last?
Many last 7 to 10 years. Test yours each spring and fall, and replace it before it fails if it's older than that.
Why does my sump pump run constantly?
High groundwater, a stuck float, a failed check valve letting water back into the pit, or a pump too small for the inflow. If it never stops, have it checked.

Make sure your sump pump works before the next storm

A sump check, honest advice on backup options, and help with the City rebate.

Get Service(613) 294-0864