Leaving your RV’s gray valve open when fully hooked up allows you to take long showers without worrying about dumping or filling up the gray tank. But what about sewer smells that can come up from the campground sewer system? Here’s how to get the best of both worlds!
One of the luxuries of staying in a full-hook-up campground is the ability to use water freely for showers, cooking and washing dishes. The sewer connection allows you to leave your RV’s gray valve open, so water can run right out instead of filling up your gray tank.
Of course the black valve can NEVER be left open, since “solids” will build up in the black holding tank when the “liquids” run out. But there’s a fair amount of discussion about the gray valve. Some people recommend that you should never leave the gray valve open either, as it can allow odors from the park’s sewer system up into your RV.
Leaving the gray valve closed does mean having to pay attention to the water level in the gray tank, and dumping it every few days. Seems like a shame to have to do that when your RV is connected to a sewer line, especially when you’re staying in a full hook-up site for an extended period of time.
Even though the drains under every sink and shower in an RV are equipped with a p-trap, there is a pipe with a direct connection to the sewer hose…. leading to the tank vents on the roof of the RV. This can allow air from the sewer system to come up through the roof vents. If you’ve ever smelled sewer odors in a full hook-up campground, it’s possible that someone’s RV is venting the park’s sewer system out through their roof.
In a recent RV Travel newsletter, we read about the simplest way imaginable to enjoy the luxury of a full hook-up RV park. You can leave your gray valve in the open position so water runs right down the drain. You don’t have to pay any attention to how full your gray tank is and you don’t have to dump it every few days. But there’s no chance for sewer odors to escape either. It’s the best of both worlds.
Watch the video to see how to do it!
Please use your full hook-up powers responsibly and don’t waste water!
Just a brief follow-up... Although this wasn't a video about tank dumping, it is related, and there were some comments and questions about it. If the gray valve is left open, there isn't any gray water available to flush the sewer hose after dumping the black tank. Here's how we handle that.
Conserving water and monitoring tank levels are just part of life for most RVers, so it's a luxury to be able to forget about it once in a while. When we're in a full hook-up RV park for an extended stay, leaving the gray valve open allows us to take longer showers, while completely ignoring the level in the gray tank. We just use the trick we demonstrated in the video to prevent sewer odors from coming in through the open gray valve.
Then all we need to do is keep an occasional eye on the black tank level. Since we often take the load (sorry) off the black tank by making periodic use of the park's bathrooms (as long as they're clean), it takes a solid (sorry again lol) two weeks or more to fill it up. When it shows 3/4 full, we close the gray valve for a day or two, allowing gray water to accumulate in the tank.
When we're ready to dump, we take a few seconds to put the entire sewer hose back up on the sewer hose support, then dump both tanks, black first of course. Plenty of water has now accumulated in the gray tank, allowing us to flush the sewer hose after dumping the black tank. When we stay in one place for an extended period, we appreciate being able to completely ignore both tanks for two-plus weeks at a time. This way of managing our tanks allows us to do that.
This is a perfectly fine way to handle shorter stays too. After boondocking for extended periods, we'll sometimes treat ourselves to the luxury of full hook-ups for a week or so, leaving the gray valve open and using the same sewer hose technique. We simply close the gray valve a day or two before we'll be leaving the park, and dump both tanks on the morning of our departure.
We don't pretend to be experts on any particular RV topic, and mostly know about maintaining our own rig. But many systems are the same on different RVs. The advice we give works well for us, but be sure to consult a professional technician if you're unsure about working on your own RV.
With valves open the odor may not just be sewage but methane gas which can accumulate in your holding tank. We have also been in parks where there are things like cockroaches and sewer flies down in the underground sewer lines. Some of these critters can and will swim through your P-trap - roaches can survive for days underwater. Holding tanks are designed to hold and not as a flow-through system so they should be used as they are designed. There are reasons. Think long and hard before deciding to leave valves open. The dipped hose P-trap may work if it is done perfectly but can cause problems if everything does not stay perfectly setup. Some think grey water is a good flush for black but keep in mind that grey can also contain disease bearing pathogens that only a very good flush with lots of clean fresh water can eliminate. Raw sewage of any kind can be a serious problem.
ReplyDeleteThanks Sue & Brian for the additional thoughts on this topic. The potential for any accumulation of gasses inside the holding tanks can be eliminated by the use of quality roof vents, such as 360 Siphon Fume Extractors, which create continuous positive air flow up and out of both tanks.
DeleteWhile we've read about the potential for critters such as sewer flies getting into RVs through the sewer system, we've never experienced anything like that, while leaving our gray valve wide open during 11+ years of full-timing. As we only recently learned the sewer hose p-trap trick, we didn't even have that small water barrier all those years, and have never had a problem, nor do we know anyone who has. And we don't agree that the gray valve was "designed" to be used in the closed position only. If it were, it would probably be spring loaded. lol
We appreciate where you're coming from, but our attitude is slightly different. While we're thoughtful, considered and careful about our RVing practices, we also enjoy living our lives free of unnecessary fear or alarm. We certainly don't see our gray water flowing freely down and out of the RV as a raw sewage, disease-bearing pathogen danger. That's why boats can freely release gray water, even in harbor (most boats don't even have a gray tank), as there is a dramatic difference between soap & food particles and human waste. If gray water pathogens were a danger, we'd suggest that leaving it stewing in the tank would pose a greater threat than simply letting it run out.
I don't get it. Especially since the stinky slinky hose is presumably already deployed, what's the huge deal of pulling a clean handle for a few minutes every 3-7 days? We're a family of four who never pay for site hookups, seldom use the campground showers/toilets, and still seldom get near to full tanks faster than twice a week (with lots, but perhaps efficient showers). For 90 seconds twice a week, this is WAY over debated...
ReplyDeleteBtw, as an engineer, the issue with "designed to be closed valves" is misunderstood slightly - many gate cable's seals take on a deformed set when left open for prolonged periods, and then don't seal as tight when closed. Other seals take a flattened set when held closed and don't press as tight even though they mate perfectly. Both are not so common or severe as to worry about it. What IS a concern is if you (naughty) allow significant food wastes down the grey pipe, and leave the valve open you have the same "slow solids" issues as newbies who leave the black valve open. The slow solids tend to build up on the ripple of the gate valve and jam it, and THAT is where all the open valve leak issues/stories really come from. For my money and time, just pull the fast dump handles weekly!!!
Wolfe Rose
Hi Wolfe. Nothing is being "debated" here. We never said that there was only one way to manage the gray valve... but simply offered an alternative. It's not the "huge deal" of pulling the valve (which is of course very easy), so much as the luxury of being able to completely forget about having to keep an eye on the level in the tank from time to time. As full-timers who do a lot of boondocking, that is indeed a luxury which we appreciate, as resource management is generally an ongoing task.
DeleteYour tanks must be larger than ours. When fully hooked up after a week or two of boondocking, a couple of long-ish showers, 2 or 3 loads of laundry and cooking somewhat more elaborate meals (i.e. more clean-up afterwards) can easily fill our gray tank in one day, or less. The last thing we want to worry about when paying for a full hook-up is flooding the RV from an overflowing shower drain while the washing machine is running. That would be the DOH! of all time for us, since we're connected to the sewer! lol
As far as damage to the gray valve seal, our 9+ year old RV still has its original seal, working perfectly leak-free since day one, despite almost always being left open at full hook-ups. If leaving it open had caused a problem, we certainly would have made a change to our procedures.
We know our choices aren't necessarily best for part-timers or weekenders, or even all full-timers. Everyone's needs, preferences and habits are different. We just shared a technique that we've found works well for us. As the video currently has 213 thumbs up and zero thumbs down, we're guessing that others may appreciate this option as well. Thanks so much for your thoughts and input. We value everyone's voice on all RVing topics. Safe Travels!
I didn't mean to debate your certain expertise - I was referencing how much goofy debate over tanks I've heard from various other RV folk when (IMHO) power management is 10x as complex as water. People debate "getting away with" leaving black valves open, just "how" dangerous is using your white hose to rinse your toilet and then fill your fresh tank, etc. Doing it right is quick and simple, but people seem determined to push wisdom, take chances, or outright do things wrong. The p-trapped hose is a great idea for long stays, but it's still easier FOR ME to just close the valves until I want to dump forcefully - my valves are right under the tanks and (i've timed it) take 90-100 seconds to drop most of 84 gallons safely.
ReplyDeleteMaybe there's a feedback loop of knowledgeable people finding dumping trivial because they know the right ways to prevent "black watered shoes", not waiting for the tub to backup before dumping, etc. Good practices save needing remedial tactics (having the BEST tank rinser is less important if you don't let your tank collect dried 'stuff' in the first place, right?)
My tanks are 42G x3. I've always wondered at that symmetrical math at least for boondockers, as a 3x2x1 (fresh, grey, black) makes more sense in usage. We pay for power occasionally when we know we want A/C without the genny, but rarely onsite water in or out since we move every few days even when away from homebase for a month. We take efficient but very needed showers after hiking all day. We don't have a washer in our rig, so we do laundry in a Tucker tote while driving or stop at laundromats every two weeks on the road. Dishes are definitely our big water hog, so we try to use paper plates when reasonable and recycle by starting fires with them (we cook heavily, intentionally not from cans/boxes that create too much trash to store when booning). We live quite comfortably without sacrificing, but allow that we are not at our home base with "unlimited" resources.
As you suggest, different strokes for different folks, and our efficient front end saves much real worry on the dumping end. If you would otherwise be dumping every day, I can see why you resent monitoring your tanks! I had forgotten that some people have things like dish/clothes washers onboard to support...
-W
No worries Wolfe! Isn't it amazing how many different ways there are to RV, each giving us a different perspective? We all have our methods that work for us, and by sharing ideas this way, we get to pick up some new ones from time to time. Safe travels! Thanks for sharing. - Peter
ReplyDelete