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GordonThree's avatar
GordonThree
Explorer
Sep 28, 2013

Heat tape vs rv specific heat patches?

I'd like to add some freeze protection to my three season RV to maybe get 3 and a half seasons out of it.

I accept the cost of the large surface area heating pads for the gray and black tanks, but they really seem to zing you on the small pads for the sewage plumbing.

Having a constant supply of 120vac power on my TT is no problem, so I'm hoping to use plastic pipe compatible heat-tape on the plumbing instead of the rv specific heat pads.

Even the plastic compatible tape is for pipes that hold water, under pressure... every brand I've found claims its not for drainage / waste pipes, I assume because those pipes normally aren't full of water.

My logic is this... on an RV, the waste plumbing is typically going to have water in it all the time, unless its just after a dump, and after a dump, there's no need to have the heat tape turned on. If the dump station provides a hose with usable thread, I usually push a few gallons of water back into the black tank to keep whatever's left in there lubricated.

Sound reasonable?

oh, for the fresh water, only a small section of PEX runs outside the cabin, and it has a marginal layer of fiberglass on it. I'll try to fish some incandescent rope-light through the hole the pipe runs through.

3 Replies

  • Hi,

    It's too bad no one has found a safe way to use the waste heat from the propane furnace and water heater for freeze prevention.

    If there is a way to enclose your tanks, do it and include the dump valves, too.

    smk's fresh water recycling is an elegant way to go.
  • I went with 120v pads and heat tape for my exposed tanks and waste pipes. 12v load was too high in total for the converter IMO and at those temps I would be plugged in anyway. Worst case I would run the heat using the inverter while in transit. But no plan to drive ALL day in below freezing temps. I used www.ultraheat.com pads.

    I did go with 12v/120v combo pad on the fresh water as the tank is larger and more critical. Used some 12v elbow heat pads on the low point drains.

    http://www.morelectricheating.com/default.aspx?page=item%20detail&itemcode=EASY10065

    Get about 50% to 100% longer than the 1.5" pipe and wrap it around as you go the length. Need longer with 3" black water.

    Then I covered with self stick foam wrap.
    http://www.homedepot.com/p/Armacell

    This all worked fine. Had some interior fresh water pipes freeze and ended up adding a hot recirculating pump. I think I am good to at least -10F at this point.
  • we set up a '97 32' HR WFS TT for extreme cold weather. Wintered over in it in Whitecourt, Alberta in '00. -46f a couple of times, no problems.
    I used thermostatic contact heat tapes on the water lines and the water pump the same as mobile homes use, and old waterbed heaters on the fresh and waste tanks. all power lines ran up to the inverter, so when on the road with the truck runnng the water system was heated. Of course when parked we turned the inverter off and moved the heat tape plugs to shore power.
    Fresh water supply is easy with a heat taped insulated hose, if the camp can supply a freeze proof faucet. If not, then fill your fresh tank as needed from their faucet near or far.
    When winter living in an rv it is best to 'batch dump' your waste water to prevent your waste hose becoming a 3" icicle, backing up into ,even flooding your rig in the night. Never leave a faucet trickling to keep your fresh water hose from freezing. It will freeze up your waste hose. Next most importantly is to keep from the waste trickle from freezing up the possibly shallow sewer pipes. Ask the camp operator if that is a concern. If not, then heat taping your waste hose and wrapping it with waterproof insulation will do fine.
    Inside comfort and heatability is another matter. Lots of ideas abound about that as well.