Black tank flusher

[fireidiot]

Had our first weekend trip of the season and all went well until I tried to use the black tank rinse connection. I noticed I wasn't getting a whole lot into the tank, and then I could see water pouring from the underbelly. Long story short, I put about 15 gallons inside my trailer. Under the bathroom sink is what looks like an anti siphon the tube from the outside goes up to this device and then back down. This is where I found a 1 inch puddle of water underneath. I assume this piece froze, but my dealer just told me to squeeze anti freeze into the line from the outside. I assumed it went straight down into the tank. I assumed wrong. Off to the dealer tomorrow.

How would you winterize this connection without some sort of pump?

I'll take a photo later tonight when I go pull the fans out that are drying the inside right now.

Great weekend until this happened.

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[davidjsimons]

I used an electric pump on mine. I flushed system with antifreeze. I don't know if it was all that necessary but all was well when I de-winterized.


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[labs4life]

I used a $12 hand pump that can bought at most camping supply stores. This is all I use the pump for.

[SteveC7010]

We just had part of this discussion yesterday:

http://www.keystonerv.org/forums/sho...ht=black+flush

What I'd suggest is make up a little adapter to go from your outside shower fitting (or other place where the water pump can move pressurized antifreeze) to the black tank flush fitting. On my trailer, it came with a coiled hose that quick connected to the water fitting and already had a male garden hose fitting on the other end.

With the adapter, you can winterize by pumping antifreeze into the black tank flush the same as you pump it throughout the rest of the fresh water plumbing system.

Plan B would be to buy one of the $4 Camco air fittings and blow out the black tank flush.

[fireidiot]

Thanks for the replies. I didn't know it was called a vacuum breaker, I see all the threads now.

If I had a outside shower, that's exactly what I would do, but this one doesn't. I guess I'll use a water thief next time I winterize. For now, I'll see if they will correct it, but if I have any issues with this again, I'll be removing that device and installing a check valve or a manual quarter turn valve. I do not like that this connection is on the other side of my TT, so maybe it will be a good excuse to move it.



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[SteveC7010]

Originally Posted by fireidiot

If I had a outside shower, that's exactly what I would do, but this one doesn't. I guess I'll use a water thief next time I winterize.

You could tap one of the low point drains and use a piece of old garden hose to reach the black tank flush point.

[KJcachers]

Just had this happen to me today. Had water pouring out of the cabinet and running out the door. Ran water thought the flusher back in early August but never again. Never ran antifreeze or air through it. I wonder if there was enough remaining water in there from August to freeze up and break over the winter. Dammit!

[KJcachers]

Btw, cleaned it up fast and have been running a heater/fan into the vanity. Hoping to avoid any real damage as its a new camper.

[fireidiot]

Originally Posted by SteveC7010

You could tap one of the low point drains and use a piece of old garden hose to reach the black tank flush point.

That's a better idea. Thank you.

[cathcartww]

I have a short (maybe 18") of garden hose with standard fittings. I hook it up to the flushing inlet, then pour it full of pink stuff. Then I screw on the fitting that I hook the air hose too, and blow it out. I figure whatever gets left in the valve won't freeze. Only one winter, but so far so good ....

[SteveC7010]

Originally Posted by KJcachers

Just had this happen to me today. Had water pouring out of the cabinet and running out the door. Ran water thought the flusher back in early August but never again. Never ran antifreeze or air through it. I wonder if there was enough remaining water in there from August to freeze up and break over the winter. Dammit!

The standard vacuum breaker in our Keystones is a little plastic assembly that is not made out of anything durable or flexible. It's designed to keep some water inside itself and there is no way for it to evaporate away. So when it freezes, the water expands and breaks things.

The valve system in many RV toilets is equally sensitive to freeze damage.

The vacuum breaker is usually located under the bathroom sink because it needs to be at a high point several feet above the tank to function properly. So when it breaks, you've got a troublesome flood in the living area of the trailer.

A lot of us have or are planning to remove the vacuum breaker and replace it with a brass check valve just like the one on the hot water heater.

FWIW, the existing black tank flush can be adequately winterized with compressed air and/or RV antifreeze.

[x96mnn]

I bought a part at the local rv shop for $6 that has a garden hose style connection that screws on the fresh water or tank flush. On the other end looks like a tire valve which I hook my air compressor to at 40psi and blow out the black water flush. I still use anti freeze for the rest of e camper but many people winterized their entire system this way.

[fireidiot]

Originally Posted by KJcachers

Btw, cleaned it up fast and have been running a heater/fan into the vanity. Hoping to avoid any real damage as its a new camper.

I've got a fan in the vanity, and three pointing at the carpet now. Hoping to not have it get into the osb.

[KJcachers]

Luckily my bath is in the rear and the trailer was leaning towards the rear door so I was able to sweep most of the water out quickly... Minutes, and towel up the rest Before hitting the area with the heater and fan. No carpet in mine but there were a couple area rugs back there acting as sponges too so they went right out also.

[Numbers624]

A vacuum breaker and a check valve are two different devices that do two different operations you have a vacuum breaker in the line is so that what is in the black water tank stays there and will not come out into the water line that you have connected to it when you flush the tank. if you change it to a check valve can you guaranty that what in that black water tank will not come back into your drinking water if there was problem water the water line when its connected to the flusher? I found my by accident when I was winterizing mine otherwise I'd would of been like you. It should be in the videos or mentioned somewhere about it.

[gepaine]

I expect this is going to draw a lot of fire, but here goes.

I called the manufacturer of the flush system installed in my TT a while back with a question unrelated to the topic of this post. I talked with the gentleman that designed the system. He happened to mention that if I had a problem with the vacuum breaker (which I didn't), he would send me another one for free. He also said I could just remove the breaker and connect its input hose to its output hose. He was of the opinion that the breaker was unnecessary because "there is no way water in the black tank is going to climb up 2 feet" to reach the flush connection.

Just another thing to consider.

[SteveC7010]

Originally Posted by Numbers624

A vacuum breaker and a check valve are two different devices that do two different operations you have a vacuum breaker in the line is so that what is in the black water tank stays there and will not come out into the water line that you have connected to it when you flush the tank. if you change it to a check valve can you guaranty that what in that black water tank will not come back into your drinking water if there was problem water the water line when its connected to the flusher? I found my by accident when I was winterizing mine otherwise I'd would of been like you. It should be in the videos or mentioned somewhere about it.

Point #1: The vacuum breaker that Keystone uses has two major weaknesses. They tend to disintegrate on their own, and they are way to sensitive to freeze damage. Continuing to rely on the Keystone supplied vacuum breaker is pretty much a recipe for trouble.

Point #2: If you use a high quality check valve similar to the one used on the back of your water heater, the chances of a back flow are very small.

Point #3: I always use double back flow prevention by placing a hose bib vacuum breaker on the male end of any hose that I connect to the flush port. They are available in brass and plastic and look like this:


Point #4: It's a good practice to never use your white food grade supply hose to operate the black flush. 'nuff said.

Point #5: I rarely camp with full hookups so I am always using the campground's hose at the dump station for the flush. Most CG's mark that water supply to be non-potable. If I do camp with full hookups, I carry a 50' garden hose that is never used for any "clean" purpose that I use for the black tank flush. I use the same hose if I have to do a wand job on the black tank.

Point #6: I only connect a hose to the black tank flush when actually doing a flush. When I am done with the flush and as soon as I turn the water off, the hose is disconnected and stored. Leaving a hose connected to the flush port when not in use is just another disaster waiting to happen.

I am not at all concerned with any back flow of the contents of the black tank.

[JRTJH]

Way back in 1993 when we bought our Holiday Rambler, we bought the optional black tank quick flush which was installed at the factory. The hose connection on the outside of the trailer was about shoulder height above the black tank valve. I often wondered why it was like that, rather than down with all the other plumbing connections. I think it's because being "way up there" gravity drained any residual water from flushing the tank down the hose and into the black tank so there wasn't the standing water that apparently freezes and causes damage.

I still question why the black tank flush has a separate connection and goes to the black tank yet apparently it is also connected to the fresh water supply????? I ask that because unlike some are suggesting, I don't think it is connected to the fresh water supply, rather it is routed into the wall to act as an anti-siphon device so the black water won't flow out of the connection on the side of the RV. Without the anti-siphon valve, it may be possible in some circumstances to siphon the effluent out of the black tank and have a puddle of poop under the black tank flush connector. But not in the fresh water tank!!! I'm almost completely certain that those two are not connected, or else you'd just turn a valve and the city water connection and route the fresh water supply to the black flush fitting which would flush the black tank. NOPE, you have to connect a separate hose to the separate system to flush..... The fresh water and the black tank flush are not interconnected.

Camping World sells a flush system for about $30 that screws into the tank and has a clear plastic hose with a fitting on one end to connect to that flush device and the other end has a bracket with a garden hose connector which installs on the trailer frame near the black tank valves. This is so you can attach a hose to flush the tank. There is an backflow preventer valve built into the fixture in the tank.

Here's the link to the system: http://www.campingworld.com/shopping...nnection/28091

As for contaminating the fresh water system in the RV, removing the anti-siphon device won't (can't) contaminate the fresh water because the two systems aren't connected, they just run side by side in some plumbing applications. Now, as for freezing and causing damage, yes, that's very likely to happen IF the second water system in the RV (the black tank flush system) wasn't properly winterized.

I'd think that to completley eliminate the problem for future winters, if you're going to remove parts or replace with different parts, the best way to rebuild the system is simply to run a plumbing line from the black tank flush connector on the side of the RV to the fitting in the black tank and install an anti-backflow valve in that line, preferably at the tank end of the new plumbing line. That would completely eliminate any and all tank flush plumbing inside the trailer and/or inside the walls.

[fireidiot]

Originally Posted by SteveC7010

Point #3: I always use double back flow prevention by placing a hose bib vacuum breaker on the male end of any hose that I connect to the flush port. They are available in brass and plastic and look like this:

I have the same one that came with the "Tornado" that I had installed on my old trailer. It works great. I always put that back flow protection piece between my hose and the faucet. I also use a dedicated hose for the black tank. I bought a 50 foot section of forestry grade fire hose that rolls up flat into a 9 inch diameter. http://www.niedner.com/en/econoflo-162.aspx

[SteveC7010]

Originally Posted by JRTJH

I still question why the black tank flush has a separate connection and goes to the black tank yet apparently it is also connected to the fresh water supply????? I ask that because unlike some are suggesting, I don't think it is connected to the fresh water supply, rather it is routed into the wall to act as an anti-siphon device so the black water won't flow out of the connection on the side of the RV. <snip for brevity> The fresh water and the black tank flush are not interconnected.

You are 100% correct, at least as far as my trailer goes, and I suspect all of them. My Dad was a plumbing and heating contractor. I grew up helping him with all sorts of jobs so I am pretty comfortable with all things plumbing. When we bought the Cougar, the first thing I did when I got it home was get out my drill driver and #2 square bit and opened up every panel, etc. and dropped the coroplast enough to see everything. I traced all the plumbing and noted where all the wiring is located. I inspected the furnace, water heater, pump, fridge, and stove. The two systems are definitely not interconnected.

The black tank flush system is totally separate from the rest of the trailer's plumbing. It has two weak spots. We've chewed on the vacuum breaker more than enough. The other weak spot is the chintzy plastic fitting used at the connection point. I am replacing both of them this summer with high quality brass fittings.

BTW, for those that don't know, the connection point for the black flush and the connection point for the city water hook up are identical. They both have check valves in them. On the black flush, it is a secondary protection against a back flow and keeps water from dribbling out when you disconnect. On the city water connection, the check valve is required otherwise, the water pump would just push water from the fresh water tank out through there. It's one of the things that keeps your system pressurized when using the on board pump and water supply.