(Title altered for search purposes.)
We winterized our brand new Tab 400 in the middle of May due to some late season freezing temps, so- in preparation for our long awaited first trip - we got to do our first de-winterizing routine in early June. It went off without a hitch! We opened the low point drains to clear whatever antifreeze was in the plumbing, flipped our Nautilus valves to "City Water" and flushed the line. Easy-peasy! We switched to "Power-Fill" and put a few gallons of fresh water in the tank- and flushed the lines, then switched over to "Dry Camping" mode (all while leaving the Bypass on of course), and flushed the pump and the lines again... No problem. This was getting easy.
With the hot water tank still on bypass- we got ready to sanitize using a bleach solution mixed in about a gallon of water (ratio of 1/4 cup bleach to 15 gallon of fresh). I put the Nautilus into "Sanitize" mode and added the solution to the fresh water tank -It worked wonderfully. The pump was already primed from the previous flush -so it "sucked real good"... I was stoked. Next on the list; fill the fresh-water tank, draw some bleach water through the lines, let it sit overnight, drain in the morning - we're ready to go camping...!
I put the Nautilus back in Power-Fill mode, hooked up the hose, and turned on the water. I could hear the water flowing, and everything looking good outside, I went inside the trailer to watch the Fresh tank meter so I would know when to get back outside to turn off the water. Empty.... Empty.... 1/3 full... I stood there at the door and waited. 1/3 full.... 1/3 full... 1/3 full.. waiting.. waiting... I heard a strange noise. "What was that?" Maybe the weight of the water tank filling was putting pressure on the floor or something - just a natural creaking sound....? 1/3 full... 1/3 full... Something must be wrong... What is taking so long? (probably about 5-7 minutes have passed so far). I just happened to look down at the area between the fridge and the wardrobe... the floor looked, odd, right? Or, ...wait- Was the floor rising?
IT WAS!!
I ran to the water line at the house and shut off the water- then immediately called for my wife who was inside the house organizing things- "HONEY COME HERE QUICK...!" You know what I mean- like some of us do when something is wrong and we need to validate what we're seeing with our own eyes with our spouses -to make sure it's really happening... She came and saw the same thing I was seeing- the floor in our trailer in the area above our fresh water tank was...not right.
Have you guessed yet?
Our fresh water tank (bladder) was expanding like a balloon. As water was being added - the air inside the tank had nowhere to go. The tank continued to read 1/3 full, because it was 1/3 full - with water. The floor in the area in front of the bed, and directly between the wardrobe and fridge was expanded (bloated really) perhaps as much as an inch or more - with a similar bloat showing on the bottom of the fresh-water tank. I imagined our tank puffed up like a big pillow.... I opened the fresh water drain, and yes; water (and don't forget concentrated bleach solution..) came rushing out.... No problem with these tanks holding pressure I can tell you! Anyway, we were pretty freaked out at this point. How could something so simple - and something being done for the first time- come this close to being a complete catastrophe?
Know what this is?
It's the fresh water tank overflow/breather tube, located on the underside of trailer to the left of the Nautilus and behind the tire... You guessed it: a mud wasp, (or something else that does this kind of thing)- had sealed the damn overflow tube, and I do mean SEALED! - No air or water- or anything except little wasps were going to emerge from this hole without immediate intervention.
It took us about 20 minutes to pick and poke all of the "larval stuff" out of the breather tube. We used a couple of long and then longer zip ties- to get as far as we could go. The corners were a bit tricky. We ultimately opened up the lower wardrobe area to get to the drain tube from the top...which really didn't seem to help -and I did not want to mess with the crimp on hose clamps used on all of the fittings (anyone know what those are called?)

Finally- we got the tube cleaned out as best we could- and tried again to fill tank. My wife monitored the drain tube while I turned the water on- She swore she felt a puff of air...! I ran to the trailer and watched the fresh water indicator. Empty... Empty... 1/3 full.... 1/3 full.... getting nervous..... 2/3 full.... feeling relieved, the floor was not rising... yeah! I continued to watch all the way to full- and then, gloriously- water came spurting out of the overflow tube - HALLELUJAH!! We put water in our fresh tank without blowing up the trailer!!!
I flushed out all of the lines to make sure we got all of the bleach solution out of the system- then emptied, and re-filled the fresh-tank again- twice... We checked all of the hoses/plumbing wherever we had access and saw no leaks- I do not think the pressure made it into the lines particularly after I relieved it at the drain. The drains themselves appear fine. The floor while initially a little raised, after stepping around and "jumping without leaving the floor" - returned to what appears to be normal....We bought some stainless mesh drain covering to protect the area around the breather tube. And if you're wondering- yes, I had already bought and installed a stainless mesh cover for the Alde heat vent to protect that system against mud wasps and the like...
For now, things appear okay,-and actually we just returned from that first trip yesterday and all systems appear to be fine but we will continue to monitor... Now that we're back we intend to let NuCamp know about this and see if they want to do anything (via the dealer or otherwise) to check things out... Curious what other owners thoughts are on that?
There is probably more than one moral to this story, but please do check your fresh water tank breather tube for blockage before every fill-obviously. If you have a trailer with the Nautilus system - air MUST BE ABLE TO ESCAPE during fill cycles - it does not come out through the old style hose fill tube. I hope NuCamp or any manufacturer using the Nautilus system reads this and decides to put some protection on the breather tube. This should not be something any brand new trailer owner should have to experience. This should also be noted (in bold print) in the manual for both the trailer and the Nautilus system.
Hope this helps you make sure this
does not happen to you....!
Re: Frankly its unbelievable that NuCamp builds a quality camper but just doesn't make it work better...
The TaB and other nüCamp products stood out in the mass of poorly built units I had looked out. The only other manufacturer coming close was Airstream, which was more money yet. We went for a previously owned TaB400, which was in grand condition and at a good price at the time. Local dealer support has also been grand.
While there have been minor issues, they were quickly resolved by nüCamp and our local TaB dealer who provided excellent service. The TaB is well made, bit as all things mechanical, tunings can and do go wrong. It’s advanced systems, like the Alde have a bit of a learning curve, but knot that complicated or difficult to work out.