Help with backed up drain.
One of our toilets is not draining right. It fills with water and then drains down fast enough for it to swirl, but not really enough to pull a piece of toilet paper. I tried a plunger with no change. Eventually all the water drains out. It's in the basement. When you flush another toilet you can hear it making sounds (bubbling/gurgling). I thought maybe it's clogged further down the line. I was going to buy a snake and see if that helped. This morning we found some water by our furnace room. I assume it came up through the drain. It was dry around the drain, but I could see water above the trap. I also realized instead of turning the in-line humidifier off I had turned it up to 100 a few weeks ago. The heat has been on some over the last week, but I don't think enough to fill the drain. I checked the sump and it's dry. We had one light rain over the last week or so.
Any thoughts? I was going to call a plumber we've used, unfortunately they don't work on weekends.