Every year when the temperature drops below freezing we get a few phone calls from frantic home owners that say “My sump pump seems to be running, but it’s not discharging water”.
This usually happens if you have a small diameter pipe or flexible hose discharging to a low spot in your yard, perhaps that low spot is full of frozen water. We will usually suggest that the home owner un-plug the sump pump and detatch the small diameter hose pipe and install a 3″ or 4″ diameter pipe that would be pitched away from the house allowing the water to flow by gravity through the larger pipe. Plug the sump pump back in and observe that the water is actually flowing away from the house.
If you have a buried sump pump discharge line and you think the discharge line is frozen this situation is a bit more complicated. You may want to consult with a plumbing professional. You will need to locate where the discharge line leaves your house. Sometimes it is below grade and other times it comes out and is “elbowed” down into the ground and the rest is buried below grade.
Depending on the temperature and your drain line set-up you may want to temporally cut into the discharge line and attach a larger discharge pipe above grade rather than digging things up during the winter. With the ground being frozen, it could be a huge expense. Consult with a plumbing professional if you are concerned with where your water is being discharged. If you are in a city with sidewalks, ice could be an issue.
Many homes with an active sump pumps have a check valve installed which prevents the water in the discharge pipe from flowing back into the sump basin and making the pump work harder than it needs to. There are situations where you may consider removing the check valve during the winter months to prevent the freezing of trapped water in your discharge pipe. If you remove your check valve make sure you have a good pitch for the water running away from your home, otherwise the water could siphon back into the sump basin inside your home.