My AC condensate pump currently pumps through a vinyl tube directly outside my house. However, I just replaced my broken home humidifier and realized that the previous one never had its drain properly installed and it just dripped into a plastic bucket or into the crawlspace (bad). I connected the drain of the new one to the condensate pump so it can pump out the excess water from the humidifier. As it often drops below freezing here and I'm worried the tube will freeze now that the humidifier drains into the pump during the winter.
Here is the tube outlet on the side of the foundation:
I was wondering if I can tie the condensate pump line into my sewer drain in the crawlspace. I've got a shower drain with the trap in the crawlspace so I could install a PVC wye above the trap and drop the vinyl tube into there.
Here are some photos of the drain.
I assume there is a vent that goes up the wall, behind the shower and out the roof.
Is this reasonable? I was worried if I added a separate trap for the condensate pump that it might dry out during shoulder seasons when the AC/humidifier are not running. I'm not sure if this is relevant but this would become my lowest open drain and I guess would be a problem if the sewer backed up, although it seems best that this happens in the crawlspace.
I'm in Franklin County, WA if that matters, I'm not sure how to look up codes for condensate draining into the sanitary sewer.