32rdb cougar kitchen sink not draining

Da30pointer · 05-30-2020, 02:27 PM

Hi I have a 2018 cougar 32rdb that the kitchen sink does not drain. This has happened twice. The galley tank is empty and the sink still retains water. It acts like it is vapor locked. Am I missing something? I have snaked the drain from the vent to behind the stove. It seems free of obstructions. I’m at a loss.

**chuckster57** · 05-30-2020, 02:53 PM

Look under the sink. Where the drain pipe goes down is there a screwed on fitting on the top. It might be failing.

wiredgeorge · 05-30-2020, 03:12 PM

I think the screwed on fitting is a vent; common in mobile homes and apparently some campers. I believe these can be found at any home repair box store. There are some that are much higher quality than others; cheapo (like used in a camper) would be about $5-10 and the higher quality about $20 more. The better quality are worth the money imho as you don't get stink out of them. Make sure you have the correct PVC adapter, if needed, to use a different one. Take yours off before buying a new vent and if the sink drains, the vent was the issue. If not, time to start some plumbing adventures!

Da30pointer · 05-31-2020, 11:01 AM

It is boggling. I am aware of the vent. It is functioning, I can even unscrew that vent and open the tank valve and the water stayed in the sink. I ran a snake through it last year when it happened. I didn’t meet any real resistance. The underbelly is all enclosed so it is hard to diagnose anything without tearing it apart. I was just curious if anyone knew if there was a second type of backflow prevention valve that I could not see. I am very familiar with plumbing issues and this acts like a pure vapor lock issue. It will hold water overnight even. Now I went out there today and it is draining fine. Something is definitely amiss. Just not sure where to go next.

**chuckster57** · 05-31-2020, 11:12 AM

See if you can locate the tank vent on the roof. Make sure its not plugged. also it may be stuck too deep into the tank. be careful if you start pulling up as you may pull it out of the tank

**flybouy** · 06-01-2020, 06:04 AM

If you are at a full hook up site then open the dump valve and leave it open. Let water run in the sink. If it backs up in the sink then the problem is between the sink and the tank. If it drains ok then close the valve ( water still running). If the sink stops draining before the tank fills then it's not venting properly.

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