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FSAD's avatar
FSAD
Explorer
Aug 20, 2017

School me on heated tanks and enclosed underbelly stuff

I want to buy a travel trailer toy hauler that I don't have to worry about the plumbing if the temperatures drop below freezing overnight. But during the day they're fine. In other words I'm not going to camp in Sub-Zero weather for a week straight. I just might have those times when it might get really cold and I don't want to worry about my pipes freezing.

So my question or questions is/are about the heated tanks or enclosed underbelly with heat ducting through it, Etc. I guess I can understand what heated tanks are: I assume they have some kind of heaters actually on the tanks and around a plumbing Etc? But I'm not sure about the enclosed heated tanks: where people say the heater from the furnace duct goes down in there and heats up that area. So can you help me sort it out?

Thanks I've been 2 years now without a camper and we're ready to get back into it and don't want to make a mistake and buy the wrong thing.

mike
Seeking Advice
  • rockhillmanor's avatar
    rockhillmanor
    Explorer
    Aug 20, 2017
    wa8yxm wrote:
    On Trailers typically the waste lines and valves are UNDER the rig.. THis kind of scares me cause I'd hate to hit something on the road and shatter the line on the way to a place where I can legally dump.....


    X2
    I never could understand why they can't come up with a better design.

    When I first started out I wanted a Big Foot TT really bad. I finally found one that was perfect, had to have it.

    BUT when I looked at where the valves where? You had to literally get on you hands and knees and crawl underneath and reach waaay back to access them. Not to mention there were mere inches from the ground.

    I don't see how you could ever keep those from freezing being so out to the open and so low to the ground.
  • FSAD's avatar
    FSAD
    Explorer
    Aug 20, 2017
    Thanks for all the replies. I'm wondering on the ducted heat versions, is there an exit. So it goes down in there and yet eventually comes back up into the coach area? Some of you were complaining about your bedrooms being too cold because the heat is used up down there! How can you tell just by looking at something if you're buying it off of Craigslist if that is how it works is there a way to figure that out?
  • wa8yxm's avatar
    wa8yxm
    Explorer III
    Aug 20, 2017
    On Trailers typically the waste lines and valves are UNDER the rig.. THis kind of scares me cause I'd hate to hit something on the road and shatter the line on the way to a place where I can legally dump....

    On class A's often everythign is enclosed, INSIDE a bay, and there is insulation.

    Heated tanks can be one of two things
    One. They have a 'Film" that contains electric heat elements.... Kind of like the rear window defrosters, this is pealed and stuck onto the tanks and fed power either 12 V or 120V..

    Or it means the furnace had a heat duct in the "Wet" bay (how my rig is set up)

    Most "heated" tanks are good to 20F.. I have added additional heat and hit 11 once
  • WNYBob's avatar
    WNYBob
    Explorer
    Aug 20, 2017
    If you get just below freezing at night an above 40 in the day your tanks will be ok. Just keep a couple of gallons in them. It a mass to surface area thing

    But your pipe an valves are another thing! Lots of surface area and a little bit of water that will cool quickly. Most of the piping is in side, but sealed off from your heat, in a cabinet or worse (like under the shower).

    I had a TC where the CW line was directly below the opening for the electrical cord was shoved in (I could feel cold air coming in). And no insulation, bad plumbing layout to lessen the chance of freezing. This is where you need light bulbs for heat. Also check the area around the fill connections or pump cabinet.

    Hope this gives you an idea what to look for.
  • tinstartrvlr's avatar
    tinstartrvlr
    Explorer
    Aug 20, 2017
    I've got electric pads, and ducted heat (although I don't know how well it heats anything in the underbelly) and have survived several days with temps in the mid/upper 20's overnight with no issues (that I know of anyway). I turn on the tank heating pads and run the furnace at night at about 55 degrees. Also leave all the cabinet doors open so heat can get into the nooks and crannys where the plumbing hides. Did have to bring in the fresh water hose since it's not heated.
  • time2roll's avatar
    time2roll
    Nomad
    Aug 20, 2017
    If the RV actually has electric pads there should be a switch to activate them.

    http://www.ultraheat.com/

    I added these pads to my open belly trailer and did fine down one time to -15F. Although some fresh water line did still freeze so I only had cold water in the bathroom and no water in kitchen. Have since added a recirculating pump but have not been down that far to really test it.
  • stickdog's avatar
    stickdog
    Explorer
    Aug 20, 2017
    Some rvs have heated tanks by the propane furnace some have electric pads some have both. If your hooked up to electric and not paying for the electric that's the way to go even if you have propane furnace ducted heated tanks. If your boondocking you better run the furnace to keep the tanks liquid. We only have ducted heated tanks and have never boondocked but if the temps are headed south of freezing we make sure the furnace is ready to go.
  • GordonThree's avatar
    GordonThree
    Explorer
    Aug 20, 2017
    I heated my own tanks, so I know what I got and how it works...

    60 watts on the 20 gallon black tank, 120 watts on the 35 gallon gray tank - PLUS and this is the important part, heat trace and insulation on the drain plumbing and valves. 40 watt bulb in the pump bay, and heat trace on the fresh line coming off the pump (it runs outside on my trailer)

    it will take a lot of cold to freeze a waste tank, but freezing a valve is much easier, and the valves are the weak link, much easier to damage than the tank.

    to keep the fresh water system limber, a pump on a timer recirculates hot water through the cold water line every 20 minutes.

    my system's good to about -14F and then exposed plumbing for the bathroom that I can't access starts to freeze up - my plan is to run the recirculation more frequently or continuously when it drops past -10F
  • rockhillmanor's avatar
    rockhillmanor
    Explorer
    Aug 20, 2017
    You have to PHYSICALLY get under or into and LOOK at what the manufacturer is calling "heated" anything before you buy! Don't even bother asking the salesman either.

    I found out my "heated" tanks turned out to be nothing more than splitting my bedroom heat duct and sending half of the heat intended for the bedroom to the sewage bay to 'heat' the tanks.

    Yup my sewage tanks and valves never freeze but I sure do get cold in winter time in the bedroom with half the heat being diverted to the sewage bay. :R

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