Defrost a frozen pipe-PVC, Underground

Our neighbors have a sump pump in thier basement that feeds into a PVC pipe that dumps over the cliff into the lake (fairly common here). There's a cleanout right near the house, then probably 60-70' of pipe that leads to the lake. Somewhere in that 60-70' it froze, or so it seems. Their sump pump is cycling every few minutes trying to pump out the water but it is just coming up the cleanout rather than going out the end of the pipe (however since the cleanout appears to be about 3-4' higher than the pipe, it's only pumping out a tiny bit, then the pump cuts off and the water goes back into the sump pump hole and restarts the cylce over again). It appears they have a french drain or weeping tile that runs into the sump pump basin that's feeding this-there's a 4" pvc pipe that's trickling water into the basin. We're afraid it's going to fry the sump pump eventually and flood the basement. We tried dumping buckets of hot water into the clean out, but that didn't work. We're trying to figure out how to run a hose out into the cleanout and down the pipe to the "blockage" and run hot water into it, but our garden hoses are buried in our shed for the year, so that's going to be a challenge. The weather forcast isn't calling for above freezing temps anytime soon either, so letting nature take care of it probably isn't going to work.

any ideas on how to defrost this?? Can't use the ol' hair dryer trick since it's underground.

Hmm...we've got a "dirty water" pump we might be able to use that we could reroute. There appears to be a hole that we could run a hose out of for now. Their pump is plumbed into larger piping that we don't have a way to do anything with. I guess one way or the other, we're digging our hoses out!

Check valve sounds like a good idea, we'll have to let them know. Never had a basement, so we've never had to deal with sump pumps, lol.

Ehouse said:

Unless the end of the pipe is hanging in mid air out over the cliff, Slide a piece of pipe or rebar in just to check. You may be able to bust it out from that end.

Click to expand...

Actually, it is. I'd say at least 5-6', and our cliff is in the range of 20' from the beach to the top. It's placed so far out to try to prevent the run off from eroding it any more than the lake itself already does. There is an ice formation (like an upside down stalactite which I can't think of the name for) from the ice buildup on the beach up to the pipe. I think the sump pump pumps out so little water at a time that it isn't much more than a trickle by the time it reaches the end of the pipe, allowing it to slowly build an ice dam.

I forgot to mention we did try salt in the cleanout as well. Didn't work.

So...there's a second pipe...orangeburg...that might be the actual pipe the sump pump uses. We just hooked up our little sump that runs on a garden hose for now. There's a mess of plumbing there, at least that should keep it from flooding. Thanks for all the suggestions!