Windshield washer fluid in dishwasher drain?

[gyrfalcon]

Interesting to hear of a dishwasher going straight to a main drain. Typically, they plumb in to the kitchen sink drain and most commonly the kitchen sink garbage disposal. I don't suppose there is any way to reroute the drain to the kitchen sink? Barring that, is it a trap which is freezing or just the horizontal section of the pipe? If it's the horizontal section, any chance you can give it a slight slope? May require re-working the attachment to the main drain, but even a small amount of slope would allow it to completely drain and may eliminate the freezing.

Maybe things you've already thought of, but just thinking out loud on ways to avoid the PITA of the antifreeze routine.

Nope, couldn't do that because of that very short "crawlspace" under the kitchen floor. There was no way to fit the dishwasher next to the sink or I'd have been happy to have it drain right into it like a "portable." So the route we chose was actually the one where the distance the drain pipe had to go through that cold crawlspace over the dirt was the shortest. With a 3-inch pvc pipe going through a 4-inch crawlspace, no way to give it a slope for those few inches. It is just a short section of horizontal that freezes, not a trap.

It's actually pretty amazing we were able to get a dishwasher in there at all. As I mentioned above, it's a circa 1900 small addition to an 1850 house that was put on without much of a foundation, so the entire little "wing" is only 4 inches above the bare dirt. Even if I had the money, which I don't, I'd be more than reluctant to completely redo the kitchen. It's an old house parts of which got badly "remuddled" in the '70s by the previous owners, and I'd rather make do with the few rather homely original elements that still exist than tear it all up and modernize it. (Perverse maybe, but it's a moot point anyway, given the $$ involved.)

 

[hearthofgold]

Thanks very much for the knowledgeable advice. I don't think redoing the whole thing is in the cards, but I'll certainly save your advice for future reference in case it should be. (What you describe about threading the hose is similar to what we did do to get it hooked up at the time.) The cellar walls, though, are stone, so how much digging can be done there I'm unsure of.

The cellar is not airtight, but it's never as cold as the outside air, and the stretch where the drain pipe goes through the "crawlspace" is quite short, so 5 years or so on, the pvc is still intact, knock on wood. I'm planning to get the cellar better tightened up this coming year, which should improve things a good bit. The saving grace, so to speak, is that the boiler down there does come on for a few hours overnight when it's really cold, which keeps the cellar from getting too far into the deep freeze.

Thanks again. Valuable advice appreciated.

Just keep in mind that if the basement is not freezing but the pipe is then most likely air is blowing on it so shoot some foam on it. For pipes to actually break they have to be quite a lot under 32 degrees, but 32 will freeze the sitting water.

 

[fossil]

For pipes to actually burst, they have to be completely full of pressurized water with no room for expansion as the water freezes (water expands when it freezes). Then, you discover the failure has occurred after temps get back up above freezing and things begin to thaw. A dishwasher drain line is never in this condition, so it is extremely unlikely that a rupture of the line would ever happen. Liquid in the line freezes and forms a plug, but has ample room to expand while freezing so as not to threaten the pipe.

 

[gyrfalcon]

Just keep in mind that if the basement is not freezing but the pipe is then most likely air is blowing on it so shoot some foam on it. For pipes to actually break they have to be quite a lot under 32 degrees, but 32 will freeze the sitting water.

I haven't taken a thermometer down there, but given the pattern of all this, my best guess is that the cellar is typically around 20 degrees or so warmer than the outside, which is why the pipe doesn't freeze until the outside temp is down in the low teens or below for several days. As far as I can tell, the very low-rise foundation around the kitchen addition is quite solid -- not the faintest glimmer of light under there, so the pipe isn't being hit by any drafts.

 

[gyrfalcon]

For pipes to actually burst, they have to be completely full of pressurized water with no room for expansion as the water freezes (water expands when it freezes). Then, you discover the failure has occurred after temps get back up above freezing and things begin to thaw. A dishwasher drain line is never in this condition, so it is extremely unlikely that a rupture of the line would ever happen. Liquid in the line freezes and forms a plug, but has ample room to expand while freezing so as not to threaten the pipe.

Thank you. That's what I've been thinking. Since it's a horizontal stretch of a few inches, with many feet of fairly wide, empty pipe above and below, there's plenty of room for ice to gradually expand into empty space. So the whole deal is a nuisance, not a potential catastrophe. (OK, losing the use of the dishwasher periodically for several days at a time in the wintertime is a minor catastrophe, but usually survivable.)

 

[semipro]

The jug of windshield washer deicer fluid I have has no info about the ingredients. Is it safe to assume that it's methanol? Or do different makers use different ingredients?)

I looked up several MSDSs for washer fluid and in all I viewed the main active ingredient was methanol. I was pretty sure this was the case but wanted to verify.
MSDS in general are a great resource for figuring out what is in stuff.
You should be able to find the specific MSDS for the washer fluid you have available.

I guess one thing to consider is whether the methanol could degrade your plumbing materials whether the drain trap or dishwasher hose. Alcohols are frequently blamed for damage to vehicle fuel lines and other fuel system parts, probably with good reason. I suspect RV antifreeze would be much less likely to damage plumbing.

My suggestion, use the washer fluid to hold you over until you can get some RV antifreeze (p. glycol).

 

[gyrfalcon]

I looked up several MSDSs for washer fluid and in all I viewed the main active ingredient was methanol. I was pretty sure this was the case but wanted to verify.
MSDS in general are a great resource for figuring out what is in stuff.
You should be able to find the specific MSDS for the washer fluid you have available.

I guess one thing to consider is whether the methanol could degrade your plumbing materials whether the drain trap or dishwasher hose. Alcohols are frequently blamed for damage to vehicle fuel lines and other fuel system parts, probably with good reason. I suspect RV antifreeze would be much less likely to damage plumbing.

My suggestion, use the washer fluid to hold you over until you can get some RV antifreeze (p. glycol).

Ah, more good info. Thanks again! I wasn't aware of the existence of MSDSs, I blush to admit. So thanks for that resource, too.

I was able to get the RV stuff at the Agway this morning, glugged some of that into the drain, and we'll see how it goes after a day or two of fairly brutal temperatures.

 

[firefighterjake]

I'm very aware of this, but as far as I know, I do not have animals in my septic system.

What? No alligators . . . oh wait a minute . . . that's New York city, right?

 

[Ehouse]

Being a drain and not a trap or a feed its normal state is full of air. I would try heat tape around the pipe at the point of entry into the basement, or a light bulb with a shield over it and the pipe. The warm air in the pipe should rise and keep the DW drain clear.

 

[Ehouse]

Another thing you can do is cut in a clean out at the bend in the basement where it angles down. You'd then have a strait shot to the blockage to clear it with a bar (gently) or hair dryer.

 

[Ehouse]

Here's something else to consider; I had my main drain freeze up in an extended cold snap a couple years ago, it froze where it passed through the stone foundation, not in the ground and not in the basement. I'm thinking the pipe may give up more heat to the stone than to either the loose earth or dead air around it. If you have room, slide some pipe insulation along the pipe from the basement end or foam it. Just foaming the pipe in the crawl space might not do it.

 

[gyrfalcon]

Here's something else to consider; I had my main drain freeze up in an extended cold snap a couple years ago, it froze where it passed through the stone foundation, not in the ground and not in the basement. I'm thinking the pipe may give up more heat to the stone than to either the loose earth or dead air around it. If you have room, slide some pipe insulation along the pipe from the basement end or foam it. Just foaming the pipe in the crawl space might not do it.

All great suggestions... and I'll save them for my next house. This is a minor annoyance that I think will be solved with the RV antifreeze, whereas getting at the (pvc) pipe in that tiny uncrawlable crawlspace would require some serious excavation. I'm also dubious that small interventions just at the point where the pipe emerges into the cellar proper would have much of an effect.

I could probably even solve this, or at least reduce the frequency of it substantially, by just running the dishwasher a couple times a day in the coldest weather, But given the flooding in the kitchen that happens if I do that when the drain is blocked by ice, I'd still have to get down under the counter and pour hot water manually into the pipe to be sure it was open before I ran the dishwasher, so I wouldn't be gaining all that much in convenience.

I figure if the RV antifreeze does the trick after several days of this single-digit daytime, zero or below overnight, I'll have my solution.

 

[Jags]

I figure if the RV antifreeze does the trick after several days of this single-digit daytime, zero or below overnight, I'll have my solution.

It will. I have no doubt.

 

[gyrfalcon]

What? No alligators . . . oh wait a minute . . . that's New York city, right?

Y'mean Noo Yawk?

 

[semipro]

I figure if the RV antifreeze does the trick after several days of this single-digit daytime, zero or below overnight, I'll have my solution.

But you can't imbibe the antifreeze
at least you probably shouldn't.

 

[gyrfalcon]

But you can't imbibe the antifreeze
at least you probably shouldn't.

True! Pink stuff looks like kiddie bug juice anyway. But I've still got that bottle of 100 proof vodka in the cupboard.

 

[Ehouse]

It will. I have no doubt.

Hmmmm... I have a doubt. If the drain is only made up of vertical and horizontal elements, how is the anti freeze going to stay in the pipe? Unless I'm missing something you'll just be pouring it down the drain to your septic.

 

[gyrfalcon]

Hmmmm... I have a doubt. If the drain is only made up of vertical and horizontal elements, how is the anti freeze going to stay in the pipe? Unless I'm missing something you'll just be pouring it down the drain to your septic.

The short section of horizontal pipe never empties completely because it's horizontal. Water sits in there, then in very cold weather, it freezes and expands just enough to block the pipe with ice. The idea is to displace that water before it freezes with antifreeze, which will sit there and not freeze.

I'm actually guessing that just by very slight error when it was originally put in, the horizontal stretch ended up not being completely level but in fact rises just slightly on its way out of the crawlspace to the downspout, so the water pools right at the bottom end of the pipe coming from the dishwasher, like an accidental trap.

If liquid, whether it's water or antifreeze, all emptied out into the main drain, there would be nothing in there to freeze and block the dishwasher drain to begin with, right? So the idea with the antifreeze is to displace the pool of water that's causing the (very occasional) blockage with stuff that doesn't freeze.

 

[Ehouse]

The short section of horizontal pipe never empties completely because it's horizontal. Water sits in there, then in very cold weather, it freezes and expands just enough to block the pipe with ice. The idea is to displace that water before it freezes with antifreeze, which will sit there and not freeze.

I'm actually guessing that just by very slight error when it was originally put in, the horizontal stretch ended up not being completely level but in fact rises just slightly on its way out of the crawlspace to the downspout, so the water pools right at the bottom end of the pipe coming from the dishwasher, like an accidental trap.

If liquid, whether it's water or antifreeze, all emptied out into the main drain, there would be nothing in there to freeze and block the dishwasher drain to begin with, right? So the idea with the antifreeze is to displace the pool of water that's causing the (very occasional) blockage with stuff that doesn't freeze.

Ah! So the short section is horizertical! Now I get it. Guess we'll find out if it works real soon!

 

[gyrfalcon]

Ah! So the short section is horizertical! Now I get it. Guess we'll find out if it works real soon!

Yeah, sorry if that wasn't clear. Funny how many words one can use up trying to describe something you could show in 2 seconds just by gesture.

I'm going to wait until Sunday, after a nice double-digit below zero overnight, to see if it works. I figure if it does the job after the brutally cold week we'll have had by then, I'm golden.

Got a pic of that wonderful sounding stove of yours?

 

[Ehouse]

Yeah, sorry if that wasn't clear. Funny how many words one can use up trying to describe something you could show in 2 seconds just by gesture.

I'm going to wait until Sunday, after a nice double-digit below zero overnight, to see if it works. I figure if it does the job after the brutally cold week we'll have had by then, I'm golden.

Got a pic of that wonderful sounding stove of yours?

Hope it works! I do have a couple of pics., New years res., figure out how to post 'em.

 

[ironpony]

If I have read everything correctly, there are several issues,

3 inch pipe holding water is at least 3 inches out of level going up hill, not good however

if it did have correct fall and did drain completely, you will have sewer gas coming back into the house because you have no p trap

so if you can not fix it properly, leave it as is, at least you do not have sewer gas coming back into the house.

also the way it is described I would say it is safe to say there is no vent allowing air behind water to allow proper drainage which could be causing an air lock in the drain line..

 

[Ehouse]

If I have read everything correctly, there are several issues,

3 inch pipe holding water is at least 3 inches out of level going up hill, not good however

if it did have correct fall and did drain completely, you will have sewer gas coming back into the house because you have no p trap

so if you can not fix it properly, leave it as is, at least you do not have sewer gas coming back into the house.

also the way it is described I would say it is safe to say there is no vent allowing air behind water to allow proper drainage which could be causing an air lock in the drain line..

Phooey, I was gonna lay back 'n see if the RV anti worked, but now you've gone 'n made it interesting. I don't think the slope in the "horizontal" pipe is enough to create a trap, therefore the drain is vented back up and out the DW. However, Its also close enough to the main drain stack to be vented there, so little or no sewer gas getting out the DW. Well vented so air lock is not the problem. I'm writing this while testing out my own plumbing system by tossing various celebratory fluids down my neck. Ten minutes to go. Will I be able to pee with my mouth closed? Cheers! and a Happy New Year!

 

[Smoke Stack]

Ah! So the short section is horizertical! Now I get it. Guess we'll find out if it works real soon!

Excellent hidden sarcasm, or, irony if you like.

Horizertical...

 

[gyrfalcon]

Phooey, I was gonna lay back 'n see if the RV anti worked, but now you've gone 'n made it interesting. I don't think the slope in the "horizontal" pipe is enough to create a trap, therefore the drain is vented back up and out the DW. However, Its also close enough to the main drain stack to be vented there, so little or no sewer gas getting out the DW. Well vented so air lock is not the problem. I'm writing this while testing out my own plumbing system by tossing various celebratory fluids down my neck. Ten minutes to go. Will I be able to pee with my mouth closed? Cheers! and a Happy New Year!

Nah, no sewer gas. At all. And I don't know where the "3 inches out of level" idea came from. Maybe it's 1/8 or 1/4 inch out of level, max. There flat out isn't room for it to be more than that with a 3-inch pipe in a 4-inch space.