Sinks won't drain

[dlwilliams48]

Worked fine the last time I used the camper, in January. Now the outside kitchen sink and the bathroom sink won't drain. The outside sink overflowed and caused quite a mess. I see a false vent under the kitchen sink and the bathroom sink but appear OK. Anything else I can check? It is a 2013 model so well out of warranty. Plus I am on the first leg of a 1000 mile trip to a campground and 450 miles from home. Can't go 3 weeks without water. Any help greatly appreciated.

EDIT: Well, apparently there was some kind of vacuum that prevented it from draining. The campground host came over and said it was probably a full gray water tank. I said not likely because the bathtub would have water in it. Anyway I had emptied the gray water tank before winterizing. Then she said maybe it was a vacuum, and proceeded to open the gray water drain! I said you shouldn't be doing that, but she said she would tell the ranger. Anyway, a boatload of clear water came out and now it seems to drain. Not sure what was going on, but hopefully that was the problem.

[mark5w]

That's a vacuum release under the sink. Probably not working. There should be a vacuum break on a stand pipe under each sink, it's a common problem. They are available at Lowes or Home depot. The purpose of the vacuum breaker is to let air into the tank when you open the big valve outside.

[dlwilliams48]

Thanks for that information, Mark. Sorry I haven't gotten back on but I was on the road until yesterday and just didn't get on the Internet.

Still not sure I fully understand what happened... it seems to be draining fine now, and I have dumped the gray water since so I know the sinks are emptying into the tank. I removed both vacuum releases under the sinks (bath and kitchen) and both seem fine. Pretty simple construction and the rubber was still very pliable. What appears to have "fixed it" was when the gray water tank was opened. Weird. Hope it doesn't happen again though.

[mark5w]

Glad it's now working for you.