Sump Pump Winter Checklist for Minnesota Homes

Many people assume their sump pump gets the winter off. In practice, groundwater keeps moving under the frozen surface, and a midwinter warm spell or rain on snow can send water to the pit with little warning.

Homes close to Lake Minnetonka, ponds or wetlands may see the pump run on and off through much of the year. If yours runs in January, that is not necessarily a problem. What matters is that the water has somewhere to go.

The discharge line carries water from the pump to the yard. When it freezes, the pump keeps running but can't push water out. The pit fills, the motor can overheat, and water ends up on the basement floor.

Lines freeze most often where water sits: in a low spot, a flat run, or a flexible hose lying on the ground. Short pipe stubs that end right at the foundation can also ice over, since water pools and refreezes at the outlet.

Signs of a frozen line include a pump that runs without stopping, a pit that stays full, ice building up at the outlet, or water spitting back into the pit when the pump shuts off.

Common fixes include re-sloping the line so it drains completely between cycles, burying part of the line below the frost line, or adding a freeze-resistant fitting near the house. That fitting lets water spill out if the line downstream freezes, instead of backing up into the basement.

A plumber may also suggest a larger pipe diameter or a different outlet location. Make sure any change keeps the water away from the foundation and from your neighbor's yard, and not into the sanitary sewer, which many Minnesota cities don't allow.

Do not use a torch or open flame on any pipe. It is a fire risk, and plastic discharge pipe will melt. A plumber can thaw the line safely.

In the meantime, keep an eye on the pit. If the pump is running but water isn't leaving, unplug it briefly to let the motor cool and bail the pit as needed. Call to get connected with a plumber near you before the pit overflows.

Ice storms and heavy, wet snow can bring down power lines. A battery backup or water-powered backup keeps the pit under control while the power is out. Cold temperatures can also shorten battery performance, so test the backup in the fall.

If you use a generator, run it outdoors only, far from doors, windows and vents. Never run one in an attached garage or basement, even with the door open. Carbon monoxide can build up quickly and is deadly.

Spring melt is when most Minnesota sump pumps work hardest. Snowpack, frozen ground that can't absorb water, and April rain often arrive together. A pump that struggled in the fall is unlikely to survive March and April.

Late winter is a good time to retest the pump, confirm the discharge line is open, and move snow away from the foundation and window wells. If your pump is nearing the seven to ten year mark, scheduling a replacement before the thaw is usually cheaper and calmer than an emergency call during it.