Calling All Brainiacs:

OK guys.
Time to put down the TV remote, stare at your computer screen, exercise your mental marbles, and use some of the ever-decreasing RVA bandwidth usage.

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Recently, I experienced a "that's impossible" situation in my 2006 Itasca Suncruiser 33V motorhome.

I was taking a shower and Linda was starting to wash her hair in the kitchen sink.
Suddenly Linda became alarmed that the water in the kitchen sink was rising, even tho the water was
off and the drain was open.

There was no standing (or rising) water in the shower--which is the lowest "open" point in the gray water system. As soon as Linda went outside and drained the gray water tank, she no longer had the problem.

I can't think of any reason, even if the two "air valves" or "trap vents" under the kitchen sink and under
the lavatory sink were somehow to freeze and not allow air to enter when water was draining through the traps.

I can't believe that there could be enough water in the kitchen sink P-trap to cause a noticeable rise in the water level in the kitchen sink (if somehow the system became pressurized with air).

Regardless, I would have expected the shower pan water level to start backing up--long before the kitchen sink would back up (being the highest "open" point in the gray water system).

Maybe one of you plumbing gurus might have an idea. The problem has never recurred, but my curiosity is driving me nuts trying to figure out why the water backed up in the kitchen sink!

What am I missing??

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Hopefully, this exercise might stimulate some serious thinking and even produce some traffic on the RVA BBS.

OK guys--think, postulate, argue, or whatever. Bounce some ideas back and forth. Lets see some activity on this BBS.

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Cheers and happy travels, Mike www.backroadtravelers.com

Mike, were you north or south of the equator? But on the serious side is your wifes hair long enough to stop up the drain? But if she said the water was riseing with the water off I guess it could not be that. Back to the thinking cap.

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mike

1. You were sober at the time.

2. Linda was sober at the time.

3. If 1 and 2 are true, then there is a puzzle. Since opening the gray water drain valve eliminated the water in the kitchen sink, then the only thing I can think of is that the shower water draining had caused an air bubble somewhere in the plumbing that made it impossible for the kitchen sink to drain. I know that's not "supposed" to happen, but it did.

Could a glob of grease have held up water from running from the sink? Then, when the gray water valve was pulled the grease glob exited along with the sink water?

Can you duplicate the phenomenon? Try to get all drains and sinks just as they were when this occurred and see if it will occur again. Try Dave's thesis--sink equality .

Good luck. Maybe you need an exorcist.

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Dutch '07 Allegro Bay 34' '09 Honda Fit Sport Whatever hits the fan will not be distributed evenly

Does by chance, your rig have a kitchen gray water tank, and a separate shower/vanity gray water tank arrangement? I've never seen this arrangement in a motor home but it's fairly common in 5th wheels and TT's. If this were the case it would answer the puzzle. When your wife went out and drained the "gray water tank" the problem went away. "If" the kitchen sink has it's own holding tank, it could easily fill up and not effect the lowest point, shower drain.

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Neil

Thanks guys and gals for the ideas.

Both Linda and Mike were sober, and yes, this really happened.

I just waited to post it since I really thought that what happened was impossible. However, the other day I noticed another long lull in RVA posts, so thought I might generate a little activity on the BBS.

No, I am not a blonde, but Linda leans a bit in that direction (but only with some help from a bottle, now and then).

Our class A motorhome only has one gray water tank, not the two commonly found on a lot of 5ers.

The situation has not reoccured although we often do the duo of showering and a separate shampoo at the same time.

Hmmm, RVA might be the closest, but we usually never put a stopper in either sink. Linda uses a small tub (and can put the dirty dish water in the Black tank if we are "out and about" and need some extra storage space).

OK, time for the other lurkers to hop in and drop their two-cents worth.

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Cheers and happy travels, Mike www.backroadtravelers.com