When my house was built 35 yrs ago a heat pump was placed in the basement. A PVC line was ran under the concrete floor to a sump pump and used for the drain from the heat pump. The heat pump was later replaced with a gas furnace. Since that install there is one drain line from the furnace that goes into a condensate pump and a second drain line that has been using the pvc line under the concrete floor. That old under-floor line is now becoming clogged and not draining well causing leaks. Would it be okay to simply run the second line into the condensate pump and abandon the under-floor line? Seems simple enough, just wasn't sure why it wasn't ran that way at time of the install.

that's what i would do..

why not us a garden hose down the pvc line and open it up? The probably put it underground to avoid a trip hazard. Condensate drains will often clog in the trapway with a bacterial snot growth. a little bleach after it is unclogged will take care of it for a while.

KC, I just re-read the post. I read too fast and missed the part about it being open into a sump pump tank. you are correct. clear out the pipe and use it.