I recently purchased a newly renovated but older home in an area that is prone to basement flooding. The sump pump system was put in back when you were able to drain directly to the sewer line, new homes in the area must drain back onto the lot. The pump system itself was replaced when the renos were done 4-5 years ago (not sure if it was kosher for upgrades to be done without changing the discharge location, that's a topic for another day). There are two pumps, they are back up powered with a battery and there is an alarm that will go off if the floor in the furnace room gets wet (covering us for both sump pump/draining problems and hot water tank leaks as well). We had one very heavy rain since moving in and the pump didn't seem to be going too hard, despite the fact that the area is notorious for basement flooding I felt safe given this information. Since that heavy rain, we haven't had any rain in almost 2 weeks. Saturday night, after a completely dry day that was forecasted 100% to rain (I've never seen a 100% forecast before, only fitting that they were completely wrong) I decided it was time to set up the sprinkler for the first time. I didn't spray for an excessively long amount of time, nor did I spray particularly closely to the house but when I came inside after, the sump pump was running. I doubt the sprinkler caused it, it was more likely ground water but regardless, I went to go check it out in the basement. Here is a diagram of what our system looks like. I am not very well versed in plumbing or sump pumps at all but I'll describe it to the best of my ability. The water comes up and out of the sump pit, to the T intersection with the open top (is this to allow air in to push the water through? Like a big can of apple juice that you have to puncture twice to pour?) The water begins to pour out the drain, increasing the level of the standing water at the base of the drain almost to the height of the discharge pipe but not overtopping it to my knowledge and certainly never overtopping the drain itself. After the water begins discharging, the water in the T instersection slowly begins rising until it eventually overtops the open end of the pipe and starts running down it, to the concrete floor and towards the drain. This, to me, implied that either there was minor clogging in the discharge pipe that was preventing the water from leaving the outlet as fast as it was entering the inlet or that the pump was too powerful for the pipe size (which seems unlikely, as the former could happen slowly over time but the later was surely have been noticed by the former owner). I set up a system of towels and whatnot to direct the overflow towards the drain without overtaking the rest of the furnace room or ruining anything in it. I set up a dehumidifier to prevent mold from the humidity this would likely cause. I went to bed and checked it out again in the morning. It was still running every 5-10 minutes, still overtopping but the water was flowing to the drain and the towels were wet but the water was not dripping/flowing beyond them. I had to be out of town all day, so I left it be and came home Sunday night. Same story as before, pump still running, still overtopping, still being contained. It was midnight but I was frustrated and wanted to do something about it. Firstly I poured a liquid plumr foaming snake down the open pipe as soon as the pump ran, hoping it would sit in the pipe long enough to remove some of the build up. I followed this up by pouring boiling water down the open pipe after the sump pump pushed all the draino out to see if the heat would help at all. Due to the length of the pipes in question, a toilet snake wouldn't even make it to the elbow joint in the pipe and achieve anything but an online article said that using a garden hose could achieve the same results without the restriction in length. The situation in that article probably didn't include an elbow joint at all, and the hose was not able to round the corner. It came back up covered in some sludge, so I feel safe to say that a partial blockage is the problem at hand. After these three (admittedly poor) efforts, I waited for the pump to run again. It went, and overtopped the same as before but I noticed a bit of debris floating in the water that came up. It soaked the fresh towels I set up at the base of the vertical pipe and as it was 2 AM, I figured I'd deal with it in the morning. When I woke up, tired and feeling like a zombie, I quickly checked the situation before leaving for work and noticed only those same towels were damp and the ones closer to the drain itself were dry. Either the sump pump stopped running shortly after I went to bed or the next few discharges had knocked some of the weakened debris through the line. So, in this situation, what should I do? Go home tonight and see if the pump is still running, if it is and isn't backing up anymore I could use a few more rounds of foaming snake to finish the job, if it isn't running anymore I could use another foaming snake and not have it pushed through by the pump 10 minutes later (and then manually flush it out with hot water after the recommended hour). Or should I just call a plumber and admit I'm out of my league here? I am trying to become more of a "do it yourself" type and I'm willing to study things on the internet and seek help from the forums when needed but I'm also willing to let the professionals take over when required. Additional Notes - There are two furnaces in this room, they both have a condensation line at the top and the bottom of furnace (is this normal? I thought there was normally only one?). The furnace closer to the drain has both lines connect to eachother and drains to the sewer drain, the other furnace has the lower drain also go to the sewer drain and the upper one actually flows into the top of the open pipe that is overtopping. The water coming through here is minimal and likely not of import but I figured I'd share regardless. There are two red plastic handles ont he pipe close to the sump pit itself, I have no idea what these are for or if they would help with anything. I also have no idea where the vertical pipe at the other T intersection is for.