I installed an Aprilaire whole house humidifier and the drain from it is going into the floor condensate pump that my AC also drains into. The outside portion of drainage hose from the condensate pump is about 10ft long and goes into a downspout. This worked fine until we got very cold overnight temperatures in CT. I woke up to the condensate pump running continuously and a pool of water on the basement floor, because the outside portion of the drain hose had frozen up.
I would like to reroute this condensate pump drain line inside to prevent this from happening, as the humidifier will need to run all winter. I have a sump pit with a plastic radon sump cover that is close by, or the septic waste line PVC pipe that is tied into old cast iron pipe going out to the septic tank. What is the best way to do this, and how would I tie into the existing? Thank you.