When Our RV Toilet Failed 200 Miles From Civilization
We were three hours into a stretch of Nevada highway with nothing but sagebrush and the occasional cattle guard when the flush pedal on our fifth wheel went from stiff to completely dead. No water. No pressure. A hollow click and the sinking realization that we had another four hours of driving before we would hit anything resembling a town. That’s when we learned how key portable toilets for RVs really are, especially when you’re miles from the nearest service center with no backup plan.
It was 2 PM on a Tuesday in July. The temperature outside was pushing 102 degrees. We had Maggie in the back, two full water tanks, and a black tank that was already half full from the previous three days of boondocking. The nearest RV service center was in Elko, which we would not reach until after 6 PM, and that was assuming they were even open when we rolled in.
Our first move was the wrong one. We pulled over at a rest area and tried to diagnose the problem ourselves, convinced it was something simple like a stuck valve or a blown fuse. We spent an hour in the heat pulling panels and checking connections while Maggie panted in the shade under the rig. Nothing. The flush mechanism was completely shot, and we had no backup plan.
The rest area bathroom was a cinder block building with two stalls and a door that did not lock. We used it. Then we got back on the road and spent the next four hours trying not to think about what would happen if we needed to go again before we reached Elko.
We made it to the service center at 6:15 PM. They were closed. We found a Walmart parking lot, plugged in our portable toilet that we had bought two years earlier and never actually used, and learned a very expensive lesson about preparedness.
That night, sitting in the Walmart lot with a functional backup toilet and a broken primary system, we realized we had been thinking about portable toilets for RVs all wrong. We thought of them as something you bought for tent camping or festivals, not as legitimate emergency equipment for a 40-foot fifth wheel with a full bathroom. We were wrong. The question is not whether you need a backup toilet. The question is which one will actually work when your system goes down at the worst possible moment.
Why Composting and Chemical Portable Toilets Aren’t Actually Competitors
Chemical portable toilets win for RV backup use, and it is not even close. We have used both. Composting toilets are incredible for full-time vanlife or tiny home setups where they are your primary system. But as an emergency backup for an RV that already has a black tank and a bathroom? They are overkill.
A chemical portable toilet costs under $200, fits in a bay, and works exactly like your regular RV toilet. You flush, waste goes into a sealed tank, you dump it when it is full. No learning curve. No installation. No explaining to your spouse why there is a bucket of sawdust in the bathroom.
Composting toilets cost $1,000 or more, require ventilation, and need you to manage solids and liquids separately. They are brilliant if you are off-grid full time and want to eliminate your black tank entirely. But if your regular toilet breaks and you need something that works until you can get it fixed? A $100 chemical toilet does the job without the commitment.
The Two Portable Toilets That Actually Earned Space in Our Bay
We have tested four different portable camping toilets since that Nevada breakdown. Two of them are still in our bay storage. The other two got donated to a friend with a popup camper after a single trip.
The RVGUARD 5.3-gallon model is the one we reach for first. We bought it in 2024 after reading reviews from other full-timers, and it has been with us through two cross-country trips and more boondocking nights than we can count. The waste tank holds three to four days of use for the two of us, which is 50% more capacity than the standard 3.5-gallon models we tried before. That extra capacity matters when you are dry camping in Utah and the nearest dump station is 40 miles away.
The smart level indicator is the feature we did not know we needed until we had it. Three LED colors tell you exactly how full the tank is: green for under half, yellow for getting close, red for time to dump. No more guessing. No more lifting the tank to feel the weight. We glance at the light.
The rotating spout makes dumping less miserable than it could be. The 45-degree angle and the dual silicone gaskets mean we have never had a spill, even when we were dumping in high wind at a BLM site outside Moab. The whole unit is high-density polypropylene, which means it does not crack in the cold and does not warp in the heat. We have left it in our bay through Florida summers and Colorado winters, and it still works like new.
The second toilet we keep is a basic Dometic 5-gallon model that we picked up for under $200 in 2023. It does not have the fancy indicator light or the angled spout, but it has more capacity than the RVGUARD and it fits in a different bay compartment, which matters when we are traveling with extra gear. We used it as our primary backup for a full year before we upgraded to the RVGUARD, and it never let us down.
The Dometic has one quirk: the seal fails in extreme heat. We learned this in Arizona in August when the temperature inside the bay hit 140 degrees and the smell started seeping into the rig. In winter, it needs to be winterized like your regular plumbing, which means draining it completely and adding RV antifreeze if you are camping below freezing. The RVGUARD does not have that problem.
The rest of the market is either too small, too flimsy, or too expensive for what you get. We tried a Walmart portable toilet in 2023 that required dumping every other day and cracked after six months. We looked at a Laveo Dry Flush waterless toilet that costs $1,000 and uses disposable cartridges that feel like overkill for a backup toilet. If you are choosing between a dozen options, save yourself the trial and error. Get the RVGUARD if you want the best all-around option, or get the Dometic if you need maximum capacity and do not mind babying it a little in extreme temperatures.
How We Actually Empty These Things Without Losing Our Minds
The first time we emptied a portable toilet, we made the mistake of waiting until the red light came on. The tank was completely full, which made it heavy and awkward to carry. We were at a dump station in New Mexico with a line of RVs behind us, and we fumbled the whole process while people waited.
Now we dump at yellow. The tank is easier to handle, and we are in and out in under five minutes.
The trick most people miss is relieving the pressure before you open the spout. If you have been driving to higher altitude or if the tank has been sitting in the sun, the waste compartment pressurizes. Open the valve too fast and you will get splash back. We learned this the hard way on I-40 outside Amarillo. Now we crack the valve slowly, let the air hiss out, then open it the rest of the way once the pressure equalizes.
We always bring a small bottle of denatured alcohol and a rag. After we dump, we rinse the spout with clean water from a jug, then wipe the whole tank down with the alcohol. It takes 30 seconds and it keeps the smell from building up over time. We also add a dose of RV holding tank treatment to the tank after every dump, the same enzyme formula we use in our black tank. It breaks down solids and keeps the seals from drying out.
The one thing we do not do is try to dump at a regular campground bathroom. Some campgrounds allow it, but most do not, and it is not worth the argument with the camp host. We plan our routes around dump stations or we use the dump at the campground if we are staying there. If we are boondocking, we carry the waste until we hit a truck stop or a public dump site. It is not glamorous, but it is part of the deal.
Matching a Portable Toilet to Your Actual RV Life (Not the Brochure Version)
The size of your RV matters less than you think. We tow a 40-foot fifth wheel, and we use the same 5-gallon portable toilet that a couple in a Sprinter van would use. The difference is not the toilet itself. The difference is how often you are using it and how much bay storage you have.
If you are boondocking more than a few nights a month, get a toilet with at least 5 gallons of waste capacity. Anything smaller means you are dumping every other day, which defeats the purpose of having a backup. We have found that 5 gallons gives us three to four days of use for two people, which matches the interval we would normally dump our black tank anyway.
If you are traveling solo or as a couple, the RVGUARD or the Dometic will handle everything you need. If you are traveling with kids, you will want the larger Dometic or you will want two smaller units. We met a family in Colorado with three kids who kept two 5-gallon portable toilets for RVs in their toy hauler, and they said it was the only way to avoid constant dumping.
If you are using the portable toilet as a true emergency backup and not as a regular system, get something with a level indicator. You do not want to be guessing how full the tank is when you are already dealing with a broken primary toilet and a stressful situation. The RVGUARD’s LED system has saved us from overfilling more than once.
If you are in a camper van or a Class B and the portable toilet is your only option, skip the RV-specific models and look at composting toilets instead. The upfront cost is higher, but you will save money on dump fees and chemicals over time, and you will not be hauling a waste tank every few days. We have friends who went that route in their Promaster build, and they have never regretted it.
If you are weekend camping or using the toilet only a few times a year, get the cheapest chemical model you can find that has decent reviews. You do not need the fancy features. You need something that works when you need it. We kept a basic $30 bucket toilet with a snap-on seat in our popup camper for years before we upgraded to the fifth wheel, and it did the job fine.
Build Your Emergency Toilet Kit Before You Need It at 2 AM
We realized we needed a full emergency kit the night our toilet failed in Nevada. We had the portable toilet, but we did not have toilet paper that fit the smaller bowl. We did not have extra treatment chemicals. We did not have gloves or a dedicated jug for rinsing. We made it work, but it was harder than it needed to be.
Now we keep a dedicated kit in the same bay as the portable toilet. It lives in a plastic bin with a lid, and everything we need is in one place. The kit includes a four-pack of RV toilet paper, a bottle of enzyme treatment, a pair of nitrile gloves, a small spray bottle of denatured alcohol, a collapsible water jug for rinsing, and a roll of heavy-duty trash bags in case we need to line the waste tank for extra protection.
We also keep a printed copy of the nearest dump stations along our regular routes. We use apps like Sani Dumps and iOverlander to find dump sites on the road, but we learned the hard way that cell service is not guaranteed when you need it most. The printed list lives in the bin with the rest of the kit.
The whole setup costs less than $50 if you already have the toilet, and it turns a potential disaster into a manageable inconvenience. We have used it twice since Nevada, once when our flush valve stuck open and flooded the bathroom, and once when a campground’s sewer connection was broken and we had to use the portable toilet for two days while they fixed it. Having a well-stocked emergency kit alongside reliable portable toilets for RVs has saved us from countless headaches on the road.
Do this before your next trip. Buy the best portable RV toilet you can afford, build the kit, and put it in your bay where you can actually reach it. You will not think about it again until the day your system fails, and on that day you will be very glad you did not wait.
We still think about that rest area in Nevada every time we check our portable toilets for RVs before a trip. The cinder block bathroom. The heat. The four hours of driving with no backup plan. We do not ever want to be in that situation again, and now we do not have to be. Neither do you.
