We, like you at times, have been innocently hanging out in our 5th Wheel (Boyhauler) and various incredibly vile smells have occurred. I mean make you want to head for the hills smells. Ahh, such is life in RVs, right? Well. Lately we’ve had a new one and it has been very intermittent. Over the last few weeks as the weather has warmed up, I’ve been using the ceiling vent fans to bring in cool air in the mornings. I typically turn on the fan to full blast and open windows that I’d like to pull fresh air in from. Well sometimes (possibly many times), I become distracted and don’t open more than one window or even forget to open any windows. No Problem right? Not so, says the stink that began ensuing after doing so. It turns out that when I don’t allow enough air flow in, the vacuum created causes various oddities to happen, like the vent check on my kitchen sink to start fluttering, allowing gray water sewer gas to flow into our coach. This is not only difficult to pinpoint because of the stench, but was confusing because no one had ever told me why I had these stubby little pipes above the P-traps in our home. After a bit of DuckDuckGo research, I found that we RVers are privy to a Plumbing device deemed illegal for most of the developed world (sticks and bricks), known as the Air Admittance Valve (AAV). I found that these black stubby pipes save the RV manufacturers from taking the proper measure to vent the sewer pipes to the roof, so instead the AAV is a one way air valve that allows air into the grey sewer pipes and does not (when working properly) allow sewer gases to flow back out of that vent.
Therein lies my predicament, when running a heavy vacuum (2 or 3 high volume ceiling fans) against these poorly designed valves and the daily earthquakes they’re subjected to as we travel down the road, causes them to fail in short order and allow gas to slip on by.
My discovery was that I simply had to unscrew the old valve, in my case a Vent Check 2 by J&B Products. I inspected it and all seemed well, but when I screwed it back on and turned the vent on sans window opening, I began to hear a fluttering noise coming directly from the valve. I have 4 of these guys, but one happens to be located in the basement under my shower. My thought is that when the garage is open and I run the fan without windows, it forces air into the garage vent check and sucks it out of the failing kitchen sink vent check.
Based on Amazon ratings I discovered that a better brand may be the Studor Redi-Vent AAV (model B00390EMT4). Both are made in the USA. The Redi-Vent seems a bit more complex, but also higher quality.
I installed this thing today, super easy. If your old one was installed correctly, it should only be hand tight, but if not a simple pipe wrench or maybe even a jar opener will get it off. Add teflon pipe tape to the threads on the new vent and screw it back in. In my case, it seems that more than one may have failed at the same time, so I ordered a few.
One more memory that we can tell our kids when they’re older!
Adventure Forth –>