Freeze proof exterior water

[Locutus]

I don't have a bus yet, just an old Class A motorhome. It has external undercarriage holding tanks and a freshwater tank under the bed (above the floor). I use the RV in the winter for ski trips with outside temperatures dipping into the low 20's (F). Here's what I did as a stopgap measure, and it seems to work okay:

I installed two small electric tank heaters, one for each tank, black and grey water:

http://www.ultraheat.com/tank_heaters.html

Then I applied Versafoam to the underside and sides of the tanks. (I couldn't access the tops without removal.):

http://www.rhhfoamsystems.com/

The heaters use a lot of electricity, even the small ones. So I only turn them on at need. The insulation works pretty well to keep the liquid from freezing overnight. I might run the heaters while boondocking only an hour or less at a time, with genset or engine running, just long enough to get the temperature up, then turn off for several hours. If connected to shore power they can be left on, as they have an internal thermostat, provided that there is fluid in the tanks.

The freshwater tank and supply lines, and greywater sink traps are inside the cabin above the floor, so cabin heat keeps them above freezing. When I'm not using the RV, I keep it connected to shore power and use an oil-filled space heater (from Walmart) on low setting to keep internal temperatures above freezing and to minimize humidity buildup.

At the end of each trip I empty the holding tanks at an RV dumpout, so I don't need to worry about the holding tanks freezing during storage.

This method has worked so far, with zero incidents of freeze damage.

[lornaschinske]

You need to keep as much plumbing inside as possible. Anything exterior needs to be insulated and heated.

We have used the water bed heater method on our (very small) waste holding tanks of our old RV. It was an old heater from our waterbed. It was a temp setup. We were parked in NE TN thru a winter and SW NC for another winter. We tended to thaw out during the day for at least a few hours... most of the time. We wrapped our holding tanks in house foam board that was duct taped together and strapped in place. Our water hose (100 ft) had heat tape from Lowes (home type) applied to the bottom side (as much as possible) then wrapped in pipe insulation foam tubes (get at least the next size bigger than your water hose if you do it this way). At the time, we had no fresh water storage. We wrapped our tank valves with more pipe heat tape. They never froze completely shut. But I hate those crappy RV valves and will use ball valves on the bus. We would dump tanks during warm spells. We had the use of the bathroom of the house we were working on at the time. All the heating stuff had built in thermostats and only came on when the temps dropped. Heat tape is preset to 40F. We set the Waterbed heater for the same temp. The system worked pretty well. I would do it again and probably will. We will also use PEX since David has gotten pretty good at working with it and we still have one of the nifty crimpers for it. The PEX seems to hold up to the freezes pretty well. Of course we plan on NEVER being in freezing temps again... but accidents will happen and one of my daughters lives in a freezing area of NM.

You might find this site informative (scroll down almost to the bottom of the page for "Tip on building a freeze proof box for holding tanks") http://users.cwnet.com/~thall/fredhobe6.htm

[GoneCamping]

I actually lived aboard my bus for a year, and I had to winterize all the plumbing, including the feeder hose from the city water connection. Keeping most of the plumbing inside really helps, but I had most of my plumbing underneath inside the cargo bay that I built. It would still have frozen under there, but I fixed that up.

First, for the outside feeder hose, I bought a 15' piece of plain old pipe heater tape, and ignoring the warnings of NOT using it on hoses, I ran this up the city pipe to the tap, and then down the lenghth of my 10' water hose (leaving a few inches hanging out at the bus). I used wire ties to hold it to the BOTTOM of the hose (heat rises), and wrapped the hose with foam pipe insulation.

The pipes under the bus in the cargo bay got a similar treatment, but since it was enclosed I didn't feel heat tape was going to be necessary, and that stuff can get expensive, especially with extensive plumbing. Instead I used rope lights (ey it was nearing Christmas and Walmart had them for like $5 for a 18' string - choose whatever color you like). I used 3 strings of them, they use very little power (about 1.2 amps for 18 feet) and also wrapped all the pipes with foam pipe insulation...the rope lights and pipe insulation became a permanent install, I even found a temp switch that would turn the lights on when the temps dropped below 39º automatically...

The coldest it got around here was about 9ºF and I never had any freeze problems. Total cost was under $50 for EVERYTHING... Also, wrapping hoses & pipes with tin foil before attaching heater/lights & foam helps distribute the heat more evenly around the hose & pipe...

[lornaschinske]

Originally Posted by GoneCamping

... I bought a 15' piece of plain old pipe heater tape, and ignoring the warnings of NOT using it on hoses,..

WHY do they have that warning on the pipe heat tape? I have been reading RV forums for several years and have never heard of anyone having a problem using this stuff in a water hose. Must be kinda like the "this product is not approved for use in recreational vehicles" warning labels...

Nifty idea using the christmas light rope. Never thought of that but some of them do put out a fair amount of heat. Maybe we need to pick up some at the next After Christmas Sale.

[Sojakai]

I'm sure that it has to do with whatever the hose is made from. They probably dont want the hose to melt if over heated, or to leach chemicals into the water and get blamed for it cause someone didnt realize. Plus its S.O.P for S.M.A/S.O.A. (Save My/Our Ass) Warn for anything that Might happen and nobody can blame you for what does, within reason.