I've found that others are having a similar problem with newer washing machines that drain too fast for the drain. The result is that some of the water comes back up. There are three solutions I found, one is to replace the standpipe with a thicker one (these machines requires 2" and some homes only have 1 1/2" installed) or to choke off the drain hose from the machine, which can cause problems on the pump. A third option I have heard of is to drain to a sink.
Can I just do this with a breather and seal in the drain? will the breather hold against the pressure from the water and prevent the drain from siphoning back into the washing machine?
Option 1: The problem is my house is in Mexico and built with brick cinder blocks. The standpipe is basically behind concrete that will have to be broken open, and there's no telling whether or not the trap will become accessible. It's a major job that requires a lot of work and there are a lot of things unknown until a lot of the demo work is done. This is not an option.
Option 2: I tried choking the hose. It's a 1" hose and i put a cap on it with a 3/4" opening. This slowed down the overflow quite a bit, but it still flows over, and i'm worried about causing damage by choking it any further.
Option 3: I don't have room for a sink, and the only drain is the one i'm currently using. But maybe there is still a way. Is it possible to build a second standpipe that will drain into the first? I'm thinking I can use two vertical pipes, i can even go with 3". The water would go down one, up another, then into the wall and down the original stand pipe. I'm hoping there is a way to get it to siphon so that the bottom U connecting the first two pipes would act like a trap. (Honestly, i don't even know if there's a trap at the bottom of the current standpipe) . But I can't figure out if this will work or if i'll just have a giant cylinder of water. I know the laundry hose isn't supposed to make a seal with the drain in the wall, but i'm thinking maybe with this setup I can still seal it with the wall and just leave an air gap where the drain enters the new standpipe.
Edit: Option 4 is a GVII (genesis valve) valve that gets sealed into the drain and lets the water pressure push through the drain, but when the pressure is gone it allows it to vent again. but it looks like they don't make them anymore and i can't find anything like it. it's not just a check valve.
I don't know the physics of this setup or if i'm missing something.
