With the hot, muggy weather in Michigan, my home central AC is working overtime. Naturally the condensate drain is plugged so I need to clean it out. Of course the installers of the owners before me installed it in a way that it cannot be disassembled or blown out without cutting the PVC pipes. I will be modifying it to better deal with this going forward.
But I have a mystery on the present setup that perhaps you more HVAC literate guys can help me with. I may not be understanding how the present system is setup. In the 1st pic below there is a fabbed trap out of 3/4 PVC lengths and elbows that (I think) drains the condensate from the evaporator coil. There was a drain plug that I removed and put a temporary brass ****** to connect a hose leading to a bucket to catch the drain overflow while I sort out my issue and modify it for clean out. I will cut the pvc pipe going into the drain line, clean out the trap, and modify the line (disconnect) where it can be opened more easily in the event of future issues and clean outs. No big deal here. But I was puzzled why no air vent above the trap. I can add one easily enough if it is needed when modifying the system. The drain line below the trap runs to the floor and follows the contour of the blower assembly base before leading into a floor drain (all look ok).
Now my main confusion. There is a black box that I show from the side, front, and back in the 2nd - fourth pics. This box is on the side and mounted *lower* in elevation than the drain in the 1st pic. It connects to a T open at the top with a pipe connecting to the same floor drain line with the PVC trap shown in the first pic. There are two hoses inside that feed into black box within the blower assembly. To the extent I can tell, they appear to go up to the level of the drain pan that the 1st pic drain with trap. There are no electrical connections to this box (not an interlock switch). There are two small lower caps on the black box on the front and back that are labeled clean out that had (clean) water in them when I removed them to check. The PVC T connects to the back side and a fitting on the front appears to be a symmetrical connection to the PVC T that is capped. The two hoses in the blower assembly have water in them.
Have any of you seen this black box or know what it is? Is this a secondary drain and vent? Or is it a primary drain and vent and the one with the PVC elbow trap is some secondary overflow (perhaps both were not working?).
Any recommendations on improving this? It is not made to come apart easy but I can cut the pipes and add some coupling unions at a few locations.
Thanks in advance for the advice. It is surprising how much condensate the AC makes on hot and humid days! So the overflow can quickly become a big problem.
But I have a mystery on the present setup that perhaps you more HVAC literate guys can help me with. I may not be understanding how the present system is setup. In the 1st pic below there is a fabbed trap out of 3/4 PVC lengths and elbows that (I think) drains the condensate from the evaporator coil. There was a drain plug that I removed and put a temporary brass ****** to connect a hose leading to a bucket to catch the drain overflow while I sort out my issue and modify it for clean out. I will cut the pvc pipe going into the drain line, clean out the trap, and modify the line (disconnect) where it can be opened more easily in the event of future issues and clean outs. No big deal here. But I was puzzled why no air vent above the trap. I can add one easily enough if it is needed when modifying the system. The drain line below the trap runs to the floor and follows the contour of the blower assembly base before leading into a floor drain (all look ok).
Now my main confusion. There is a black box that I show from the side, front, and back in the 2nd - fourth pics. This box is on the side and mounted *lower* in elevation than the drain in the 1st pic. It connects to a T open at the top with a pipe connecting to the same floor drain line with the PVC trap shown in the first pic. There are two hoses inside that feed into black box within the blower assembly. To the extent I can tell, they appear to go up to the level of the drain pan that the 1st pic drain with trap. There are no electrical connections to this box (not an interlock switch). There are two small lower caps on the black box on the front and back that are labeled clean out that had (clean) water in them when I removed them to check. The PVC T connects to the back side and a fitting on the front appears to be a symmetrical connection to the PVC T that is capped. The two hoses in the blower assembly have water in them.
Have any of you seen this black box or know what it is? Is this a secondary drain and vent? Or is it a primary drain and vent and the one with the PVC elbow trap is some secondary overflow (perhaps both were not working?).
Any recommendations on improving this? It is not made to come apart easy but I can cut the pipes and add some coupling unions at a few locations.
Thanks in advance for the advice. It is surprising how much condensate the AC makes on hot and humid days! So the overflow can quickly become a big problem.

