I've started having an issue with my washing machine not fully draining. The clothes are very wet and water is standing at the very bottom. The WM is an old style analog Maytag. I've changed the spinning pump but it didnt help.
I suspect the problem is in the hose connection to the waste line. If I disconnect the hose from the waste line and let the spin cycle drain into bucket, it works great.

As you can see from the photo the hose goes vertically from the bottom into the metal pipe and is held by a clamp.
There is a backflow preventer approximately where the arrow is. I can feel the circle going up/down as I try to clean the path out. The connection from the machine to the metal pipe goes up for about 3-4 feet.

As I started reading about drain connection I dont see what I have as standard. What would you guys recommend?
Should I change just the backflow-preventer/connector ?
Add an anti-siphon of some sort?
Redo the whole thing?

To get the drain hose to ejector-pump, I'd have to run the hose vertically ~7 feet and then horizontally another 7, probably too far for this machine/pump to handle.

Just to explain, the vertical pipe is a branch from a bathroom that ties to another branch below, and then that ties into city sewer line about two feet to the right.

P.S. one more clarification - there is very little water left in the machine, so it does drain 95%, I suspect that when the downward water pressure from the machine is on a low side it cant push through the backflow preventer well enough and water stays in the vertical hose.

 

Nothing about that is to code.

You are likely getting a good gallon of water running back down the hose just from gravity... what isnt being cleaned out of the hose below the backflow preventer (which is 4-5" below your black arrow).

I'd be surprised if that 2" pipe has 1/4" of drop per foot since it looks like it's going uphill to the right.

You should have a code approved laundry standpipe, (where VTR means vent through roof) that drains to your floor level ejector pump.

 

Thank you for your reply! I appreciate it.
the pipe to the right does go downward, sorry about bad angle
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I've read that 96 inches is the maximum recommend upward lift for a washer. I just don't understand, if I lift the hose to 96 inches so it can run into pipe that goes across the basement into sewer pump, how is that better? Wouldn't water still stand in the hose?

If I were to create a standing pipe, I'd have run the bottom pipe across the floor, that just wouldn't fly ;(

I guess a new pump would work, but those are not cheap...

 

Here is a diagram with sizes and a thought on possibly adding a P-trap instead of backflow preventer. The main concern - it will increase the height even more, so it wont solve the run down in the hose.
When we moved into the house we did not have issues with drainage for 5 years. This is why I suspect its the backflow preventer thats restricting the flow. Nothing else in the chain seems to be misbehaving.

I guess I could do a test, raising the hose to P-trap length and running a temporary standpipe, or even doing a temporary p-Trap. To test out if the water will drain.

 

The higher the washer discharges the more water gets left behind.

The few installs I did in applications like yours is I set a slop sink with pump and pumped the sink up to the drain.

 

Thank you Pete. It makes sense of course.. I also came across a photo of someone's installation with a sink/pump right by the washer.
Is the smell not an issue at all? The few times I let it drain to a bucket there was a strong chemical/soap smell of graywater. I imagine a full drain into a sink would create a very strong smell throughout the house...

 

There is a small sump/pump unit that the water drains into.
It has a type of vent and it's pretty effective at containing odor.

 

I understood the water goes into sink first, and doesnt drain immediately, but eventually makes its way down to sump/pump under the sink. Perhaps I am thinking about a different setup.

 

Hey guys, I am still thinking about this and would like to avoid dropping another $250 on a piece of machinery that seems prone to failure. I've looked at a few pumps (enclosed and under sink) and all seem to have high number of complaints.

So I wanted to see if I can get away with adding a standpipe. I've made a new diagram below, here are some points:
- The washing machine is rated to pump water to 8 feet (96")
- I will close the existing 2>1.5>1.25 entry point where hose direct plugs now.
- I will cut-in a 2" wye into the lower branch with the side entry parallel to ground.
- Add a 2" p-trap into the wye
- Add 2" 24" length pipe into p-trap (24" is reasonable max for clearance, I'll try to make it a few inches longer if I can)

The washer will need to pump the water to about 78" which is not much higher than it does now.

I would also like to add a safety studor mini-vent, just in case. I know there is a vent somewhere, but I am not sure if its close enough. Adding a new roof vent is not an option. My question is - do I add the vent before or after the ptrap/wye/standpipe? I am thinking another wye with vertical pipe that ends in a studor. Am I over-engineering it?

Thank you!