For those using their toy hauler in cold conditions

[atlantaM3]

Check your underbelly coroplast! On my unit, the underbelly was not actually 'sealed' up at the back near the fuel tanks. They screwed the coroplast to a beam in front of the generator fuel tank that was much lower than the rails for the material, leaving a gap of several inches at the back. You could look over the top of the fuel tank to the front of the underbelly., so it def wasnt anything above ambient outside temp under there.

Also the space around my furnace in the basement wasnt sealed up either, you could stick you hand straight down into the underbelly. After addressing these two items, there is a lot less cold air coming in from the furnace intake.

Just some things to check if you hauler has a lot of cold air coming in via the furnace intake vent.

[farnik78]

I don’t think any toy hauler underbelly is enclosed around the fuel tank. I assume this is a safety precaution as you don’t want fuel and or vapors to be enclosed in the case of a leak.

[atlantaM3]

It isnt enclosed around the fuel tank area, ends just in front of the generator fuel tank. The issue is that were it is supposed to be enclosed, it really wasnt, since the coroplast was not brought up high enough to actually create a separation, thus cold air pouring into the underbelly over the gap at the back.

[CAG]

My Heartland Cyclone was not sealed (coroplast) over the fuel tanks. I think there is a reason and as said it has to do with safety. My unit was a 0 degree. In other words good to 0F due to the sealed and insulated underbelly. The furnace was pretty much the same as you mention on yours open to the lower area so that heat would flow to the insulated basement and underbelly to keep water lines, and the pump from freezing.



The garage was not insulated on the bottom of the 5th wheel. I wish it had been because it is also a sleeping area but the fuel tanks were also
in that area.


If you think it should have been call Jayco and ask.

[atlantaM3]

I guess I should clarify - I am not saying the area of the fuel tanks should be enclosed. The issue is that the coroplast directly in front of the fuel tanks was not sealed up to the floor, rather attached to a much lower cross bar. This left a large opening at the rear of the underbelly, so large that it would not be considered 'sealed' for the area that should have been enclosed. The gap was large enough that the underbelly would effectively be ambient temperature, it would not retain any heat in that configuration.

[CAG]

I guess you need to find out if it is supposed to be sealed and heated? If not it is simply protection for lines, electrical etc from road damage. If it is a truly heated and enclosed, as mine was, there will be insulation above the coroplast to protect water lines and tanks from freeze and the heater will be set up to pump hot air into the underbelly. My Cyclone was listed as four season, with an insulated and heated underbelly and was rated to 0F. We elk hunted at 8000 and temps to 10 with no issues. If your does not say that or is not listed that way, my guess is the coroplast covering is simply protection for road debris.



Again, to clear it up call Jayco and ask.

[atlantaM3]

It is a 4 season rated unit, polar package, tank heaters and all.

[CAG]

You don't say what rig or if you are still under warranty but if so I would be back to the dealer or calling Jayco.

[atlantaM3]

Generally I would agree. Unfortunately the apathy and sheer lack of competence dealing with Camping World service had led me to either fix things myself, or use a mobile tech to assist.

[atlantaM3]

Forgot to add - it is a Seismic. I would imagine this would potentially apply to Octane models as well.

[AZMarine]

AtlantaM3,
What / how did you seal up the gap that was just in front of the fuel tank. I have the same thing on my 2018 Octane T-30F. Underpinning from front back to just in front of fuel tank is well sealed, but there is a good 8" opening all the way across just before the fuel tank. Looking for ideas that would seal & be long lasting (relative to the existing cover of course). Pictures would help . I plan on camping in high altitudes & cold weather eventually as well.

[atlantaM3]

I used some of this insulation material I got from Amazon - https://www.amazon.com/gp/product/B0...?ie=UTF8&psc=1 - I added a layer into the underbelly too, since I had it opened up anyway.

For the gap, I cut a piece three times the height of the gap, and folded it to create a decent thickness barrier. Wedged it into place and used gorilla tape to support it. It has not moved thus far.

I had to drop the coroplast in front of the tank to get to the gap effectively.

stupid problem...

[atlantaM3]

also, after seeing how its put together under there, if you are really going to use it in cold weather, probably worth getting some pipe insulation for the water pipes. I was planning on using something like this - https://www.homedepot.com/p/Armaflex...5812/100550644 - when I open it back up next time.

Also, go around all the openings in the coroplast and check them. I had many that did not have any spray foam at all to seal the opening.

Also look at holes through the frame at the slides. There are normally some decent size holes there that aren't sealed for power/gas lines, etc. that would be allow a lot of heat to escape. I used some gorilla tape to seal the hole, but still be flexible for the pipe, etc.