Water Line Freezing Issues

steve2777 · 03-02-2021, 03:01 PM

We have a 2018 Thor Siesta 24ST. Prior to spending the winter in Arizona, I knew we'd be going through some cold nights coming and going to Cincinnati, OH, so I took what I'd hoped would be sufficient protective measures. We would be running the furnace at night, and most of the fresh water system is above the floor, and would be kept sufficiently warm to prevent freezing. However our layout had one "achilles heel": the lines running to and from the water distribution system, which is in the wet bay. The to/from lines run down through the floor, out into the cold air behind the wet bay, then turn 90 degrees into the back of the wet bay to the distribution system. Of course, this means that even though your fresh water tank and 95% of the lines between it and the sinks are kept warm, ALL water used has to pass OUT to the cold outside, through the WDS valve, and back IN to the coach. Knowing this would be a problem, I stuffed the open bottom of the WDS box with insulation, and outside behind the wet bay, I sprayed the water lines with as much expanding spray foam as I could.

Well, not good enough! One evening where the overnight temperature fell to mid or maybe low 20's for a few hours, the system froze and we had no running water, and it didn't unfreeze until well into the afternoon. I hadn't let the water drip overnight because we were boondocking and had low fresh and high grey tank levels. And it simply wasn't that cold for that long, and I'd hoped my protective measures would be enough.

I'm trying to decide what the next step is: If I'd been at a campground with electricity, I could have put my work light out in the wet bay to provide additional heat inside (although that wouldn't have helped the lines hanging out back between the wet bay and the floor). But what's the solution if you're boondocking?

The only other solution I can think of is wrapping the lines and stuffing the
WDS box with electric heat tape. The heat tape I've found is 120V AC, and I COULD wire it to run off the inverter, although that COULD take a lot of watts overnight. I also got several 7 watt 12V heat wafers that I could wire in, and place inside the WDS box, and maybe near the hoses in back if I built some kind of surrounding box out of reflectix to hold the heat in.

Has anyone tried something like this, or come up with any other approaches to this problem? I really don't want to have to winterize the coach, drink out of jugs and flush the toilet with antifreeze, just for several hours of overnight sub-freezing.

Judge · 03-02-2021, 03:14 PM

You could try purchasing 12V heating pads used to heat the black and gray tanks and wrap them around the water lines. Then you could heat the lines even when on battery power by flipping a switch.

They come in different sizes. Here is one example:

https://www.amazon.com/Heater-Holdin...07ZJN2JW7&th=1

If you wanted to go with AC instead of DC, you could try radiant floor heating mat but you would need to rig up a thermostat for it:

https://www.amazon.com/dp/B083XVP9CN...jaz10cnVl&th=1

JamieGeek · 03-02-2021, 03:22 PM

You could just put a 60w or 100w light in the compartment--if you can find a good old incandesent lamp. They produce enough heat by themselves to keep it from freezing there.

Bluetreak · 03-02-2021, 03:37 PM

We ran into a similar situation in our TT 2 years ago just after we moved to Missouri and were staying in our trailer while our house was being finished...in the dead of a bad winter for the area!

We stored water in containers for cooking, washing up and toilet use. Showers were a no-go. I could not find a way to keep an 18" section of the water system from freezing without major surgery to the rig. On the two mornings it happened, I braved the cold and took a shower in the bathhouse at the campground.

I think the 12 Volt heat pads, with insulation, are the way to go. Besides the typical RV types, there are a lot of different sizes made for commercial and industrial purposes. a search on Amazon can be useful.

Good Luck!

steve2777 · 03-02-2021, 04:28 PM

Thanks! I think I will try the 12 volt pads.

Hooligan2 · 03-03-2021, 05:01 PM

My 2016 24ST. The water lines come thru the floor into the metal box, all inside the rotocast compartment. Not outside. I use a clamp light with 100 watt bulb with temps teens or lower..(120volt) Not viable when boondocking.
Most 12 volt heat tape or pads draw 10 amps or more.
Furnace is right above that compartment. It may be possible to cut opening into compartment and use 12 volt computer fan to direct warm air from under the bed into the metal box from above.

steve2777 · 03-03-2021, 05:13 PM

Hooligan: I sure wish my water lines ran into the compartment like yours do: I'd be able to concentrate on heating only the WDS box, instead of a bundle of lines hanging out the back side of the rotocast. I guess that the location of the Girard tankless water heater covered up the pathway that allowed the lines to pass directly down into the rotocast. But what was Thor thinking, moving them out into the weather like that?

Hooligan2 · 03-04-2021, 02:03 AM

Bummer.. That does un-simpify the problem..

Campnjoe · 03-04-2021, 04:00 PM

Quote:

Originally Posted by steve2777

We have a 2018 Thor Siesta 24ST. Prior to spending the winter in Arizona, I knew we'd be going through some cold nights coming and going to Cincinnati, OH, so I took what I'd hoped would be sufficient protective measures. We would be running the furnace at night, and most of the fresh water system is above the floor, and would be kept sufficiently warm to prevent freezing. However our layout had one "achilles heel": the lines running to and from the water distribution system, which is in the wet bay. The to/from lines run down through the floor, out into the cold air behind the wet bay, then turn 90 degrees into the back of the wet bay to the distribution system. Of course, this means that even though your fresh water tank and 95% of the lines between it and the sinks are kept warm, ALL water used has to pass OUT to the cold outside, through the WDS valve, and back IN to the coach. Knowing this would be a problem, I stuffed the open bottom of the WDS box with insulation, and outside behind the wet bay, I sprayed the water lines with as much expanding spray foam as I could.

Well, not good enough! One evening where the overnight temperature fell to mid or maybe low 20's for a few hours, the system froze and we had no running water, and it didn't unfreeze until well into the afternoon. I hadn't let the water drip overnight because we were boondocking and had low fresh and high grey tank levels. And it simply wasn't that cold for that long, and I'd hoped my protective measures would be enough.

I'm trying to decide what the next step is: If I'd been at a campground with electricity, I could have put my work light out in the wet bay to provide additional heat inside (although that wouldn't have helped the lines hanging out back between the wet bay and the floor). But what's the solution if you're boondocking?

The only other solution I can think of is wrapping the lines and stuffing the
WDS box with electric heat tape. The heat tape I've found is 120V AC, and I COULD wire it to run off the inverter, although that COULD take a lot of watts overnight. I also got several 7 watt 12V heat wafers that I could wire in, and place inside the WDS box, and maybe near the hoses in back if I built some kind of surrounding box out of reflectix to hold the heat in.

Has anyone tried something like this, or come up with any other approaches to this problem? I really don't want to have to winterize the coach, drink out of jugs and flush the toilet with antifreeze, just for several hours of overnight sub-freezing.

I am assuming your coach isn't rated 4 season. This would explain it. Good luck in finding a solution. The 12v heat pads sounds like a good option to me.

Mousemate · 03-04-2021, 07:50 PM

I would suggest a small spray-foam kit and insulate the bay and lines that are exposed.

I did this in my house crawlspace and and wet bed of my rv and have had no issues since.

steve2777 · 03-05-2021, 01:58 AM

Thanks! I'm going to be trying everything.

Bob Denman · 03-05-2021, 02:17 AM

Good luck!

(I like the spray foam plan.)

steve2777 · 03-10-2021, 11:14 PM

Well, I decided to bring the water lines into the wet bay, like should have been run in the first place. Not as hard as I thought. Drilled a new hole in the wet bay and most of the original hoses still reached. Only 6 inch move needed to reach the wet bay with the new hole. Why on earth couldn't Thor have done that?

JoeDS · 03-11-2021, 01:27 AM

Quote:

Originally Posted by Mousemate

I would suggest a small spray-foam kit and insulate the bay and lines that are exposed.

I did this in my house crawlspace and and wet bed of my rv and have had no issues since.

What foam product did you use? I cant imagine being able to use "Great Stuff" foam to do that.

Mousemate · 03-11-2021, 07:08 PM

Quote:

Originally Posted by JoeDS

What foam product did you use? I cant imagine being able to use "Great Stuff" foam to do that.

I used a spray foam kit.
https://www.energyefficientsolutions...tem=FOAM605E84

I got the kit half price on facebook because it was almost out of date.
Hope this helps

Jimmers · 03-12-2021, 12:06 AM

I would think to place as your thinking into a closed bay & add a small heat duct tube to give occasional heat from the furnace / coach would be safe enough and not much money.

JoeDS · 03-12-2021, 01:08 AM

Quote:

Originally Posted by Mousemate

I used a spray foam kit.
https://www.energyefficientsolutions...tem=FOAM605E84

I got the kit half price on facebook because it was almost out of date.
Hope this helps

Thanks for info. That's pretty slick!

Did you have to put your MH on a lift to do this?

How is it holding up to rain and road debris when traveling?

Also in this thread the term "wet bay" is used. What constitutes a wet bay?

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