Discussion between FGreg and noybman

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16:34

1

Washers have their own pumps. They are designed to pump water to heights "above them" but not generally "designed" to pump a longer run than the approximately 6' drain line they come with. With that said, they will certainly pump beyond this amount, but based on how you run it, there is definite...

FGreg

Thank you for your comments. The seller claims that was how the system was originally installed (approx. 1980). They had a plumber come in and look and of course they claim no external pump is needed. So my guess is our guy is quoting the cost of the "ideal" solution and there's is quoting the practical solution. I'm trying to gather more info to decide :) thanks again!

noybman

I'm sticking with the idea "that it was put there for a reason". If the owner is original, I smell more fish, or sewage. Might be enough reason to request a sewer inspection. Is it septic or public? Is the property in a valley or base of a hill? You could probably even phone the local town municipality to inquire on overall sewer health in that area. Inspectors come in all shapes, sizes, and quality. Does the system TRULY look original from top to bottom? Or does it look like it has been serviced many times, with changes or mods elsewhere in the system?

One more note! Think of a fish tank or a siphoning setup: as long as the water table your washer is pumping into will clear the trap via weight and gravity, you are OK, but you still would want a wash basin as a reservoir in case the drain in itself gets clogged.

FGreg

Realized I had a picture I could add. The sewer is public and the property is 5-10 miles south of some mountains, so past foothills but still general grade away from the mountains. I would think the check valve would prevent sewer backup, it's the section of pipe between the check valve and the washing machine that holds water that I'm concerned with.

noybman

Where will your dryer vent go? Ideally I'd still (personally) put in a utility tub with a pump. But seeing that picture, its very likely the plumber that installed it did so to avoid siphoning sewer water with a wash machine hooked DIRECTLY to the line, with no air gap. It's not something I would do for the same reasons it sounds like you wouldn't. But it appears the homeowner would know if it worked. Did they use it?

FGreg

The vent is another issue, we're going to have to add a duct along the wall of the garage and vent to the exterior that way. The homeowner has used it for 20+ years so it does seem to work. I think they were just venting directly into the garage.

It sounds like you're recommending hooking the washer drain into something like this: a.co/5fzH3Rh

Then into the existing drain line

It seems that would mitigate most of the major issues that could occur.

@Tester101 Had the following comments: Sewage baking up into the washer, dirty stagnant discharge water sitting in the washer, premature washer pump failure, gurgling/bubbling of nearby fixtures, sewage and/or gray water being forced up other fixtures

1) Sewage baking up into the washer - Should be prevented by the check valve, no?
2) Dirty stagnant discharge water sitting in the washer - This was my main concern. My understanding now though is that it would only happen if there is a failure in the washing machine pump
3) Premature washer pump failure - Valid point, the pump would be working harder than the average washing machine pump.
4) Gurgling/bubbling of nearby fixtures - I can live with that while the washer is draining. I imagine it would be similar to the sound a dishwasher makes when it drains into the sink drain line.

noybman

22:01

Venting in a building is not wise. The Dryer manufacturers are quite forgiving on run lengths and rules, far more than the local codes. I'm dealing with this issue right now myself, so it sounds like you are doing all the right things In this regard.

Tester101

Any water in the pipe between the pump and the check valve, will flow back into the washer when the pump turns off. Too long between washes, and you could notice a stank.

noybman

Your linked item would work. I was referring to: homedepot.com/p/… with a pump like what you listed. It gives you numerous advantages above and beyond that of just connecting a washer. With this, it does mitigate the issues with more upfront investment.

Tester101

DWV systems work at atmospheric pressure, and rely on gravity to flow. Forcing large volumes of water into the system can compress the air in front of it, and cause traps to be blown out. This can lead to bubbling/gurgling/geysers. If there's a blockage in the system, sewage could be included in the geyser.

noybman

To Tester's point, and my earlier one, IF you seal the drain line between the washer and the check valve, water WILL drain back into the washer. But again, the 6' line the washer manufacturer gives you isn't enough to get back into your clothes. When the washer is done, the length of tubing FULL of water, plus any amount that gets past the check valve before it closes, is fair game back into the washer. The Washer pump is off, so water is free to enter.

Tester101

This is why washer drains (including dishwashers) are supposed to include an air gap.

noybman

22:11

+1

Tester101

@FGreg even if you install an external pump, the discharge from the pump will have to enter the DWV system through a standpipe or cistern.

There has to be an air gap.

noybman

BTW... from your picture, if you were to intentionally extend the Drain tube to the upper most point (8'???) and removed the check valve, open pipe with the opening on the uppermost part, then you would be using a washing machine "as designed" as a gravity drain, and the air opening would prevent most sewage if a backup occurred from making it's way into the washer, it would make it to the floor (mostly).

The main downfall is that 8' of washer water is in that pipe when done, and will fall back into the tub. (this is true of normal washers too, but its typically about 3-6').

Tester101

Yes, you could discharge into a standpipe near the ceiling, however you'll need a trap, and the standpipe has to be at least 18" above the trap weir.

Not sure there's enough room for that.

FGreg

@Tester101 If I'm following you, I think there is an air gap. If you look at the picture, there is the check valve then a kind of U-bend and it connects to a black pipe. That black pipe isn't the main sewer line but it runs directly to the main sewer line. I'm not sure what that next junction looks like (I don't have a pic of that), but wouldn't that first length of pipe after the U bend act as an air gap?

noybman

As far as the pump idea, putting the air gap in is fairly easy. He did say this is a garage, so it should be (literally) a straight shot UP

FGreg

22:25

@noybman With that tub, the setup would be to drain the washer into the tub, then install a pump like I linked to in order to pump the water from the tub up?

noybman

He means air gap to avoid a pressure differential from the waste water you are moving into the sewer. Again, think of a typical siphon. Without a hole, pressure can exist

FGreg

ah yea I get it now

so there'd have to be some sort of vent after the check valve, probably on the top part of that "u-bend"

noybman

@Fgreg, yes, drain the washer into that tub, and even add a faucet. Its likely to be useful for you, even if washing your hands or spraying off a car part or a garden tool. Then the pump under it, will feed the sewer drain. To @tester's point, you want to open an air gap, to the roof, where bad gasses get out of the home safely

You wouldn't use a check valve. *(you can, but you just wouldn't).... unless you know you need it or expect sewage to backup

FGreg

hmm, yea getting to the roof is non-trivial

Tester101

Yes, maybe "air gap" isn't the correct term here. Basically, you need a way to prevent pressure changes in the DWV system.

noybman

22:29

There's no crawlspace?

FGreg

it's a condo. garage (where the washer is) then 2 floors of living space (owned by me) then roof

Tester101

You don't want to compress the air in front of the slug of water, nor create a vacuum behind it.

FGreg

venting into the garage is probably a no-no huh

Tester101

How does the other end of that pipe connect to the sewer?

FGreg

unfortunately I don't remember and I don't have a picture of it

Tester101

22:33

It may be possible to handle the pressure equalization there, if it's not already.

FGreg

I have a feeling it's just a simple junction

That's the right side of the main sewer line, the black pipe from the other pic joins that pipe to the left of this pic

the arrow is the main sewer clean out cap

but I'm pretty sure the junction is just like one of those 2 coming from the ceiling

now that I think of it though, the wall the appliances are sitting against is an external wall but below grade. It may be possible to go straight up then through the external wall for both the drain vent and dryer vent

Well I think you've both helped me a lot. I appreciate the feedback and discussion

Tester101

22:58

If the drain vent is attached to the sewer, there are restrictions as to where it can vent to (Not near windows, doors, or basically anywhere people might breath it).

FGreg

@Tester101 hmm yea it would probably have to go to the roof then

most likely where the ~$3500 price tag was coming from for the plumber we had come look at it

noybman

23:52

You can go outside, but I believe code is 3' from an opening. You might want to look into it from that perspective.

FGreg

@noybman yea the external wall right above that area is the front door to the unit, a window, and a patio. it's also right next to the common walkway for the condo building. So unlikely to find a spot that is 3' clear of anything

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Discussion between FGreg and noybman