Keeping dump valves from freezing

[Grand Adventure]

We have a 2016 Evo by Forest River T2050 travel trailer with the "Arctic Package." That package includes an insulated and enclosed underbelly, increased insulation all the way around, and tank heater pads. The water lines to each appliance and fixture run around the inside of the trailer rather than between the walls, with the exception of the hot and cold lines leading from the water heater to the kitchen sink, which is on a pedestal. However, that one runs just below the thin floor and above the tanks and underbelly insulation, so I'm not terribly concerned about that one freezing, either, as long as we maintain a reasonable temperature inside the rig.

We intend to do some winter camping this season at several different ski resorts. Unfortunately, Forest River didn't see protecting the dump valves as anything important when putting together their "Arctic Package." The pipes to the dump valves drop out of the insulated underbelly before terminating at the valves, leaving them rather exposed to the elements and prone to freezing up.

As that's got the potential for a messy disaster in cold weather, we decided to do something about it. We've frost-proofed our dump valves and exterior plumbing, and made a video as we completed the job to share our idea:

https://www.youtube.com/watch?v=KABF205es_U

I welcome your feedback, including any weaknesses you still see, or any better ideas around this subject. 

[dartmouth01]

Nice.  We have a similar pipe set up on our rig, the two main weak points I found after spending about a week in 0 degree daytime temps (some of it towing) last year was 1) the freshwater feed pipe to my water pump and 2)the exposed dump tubes.  The issues reared themselves not when we were sitting still, but rather when we were driving for hours and couldn't retain enough heat in the underbelly or pipes.  I have tank heaters as well, and we were running the furnace while driving, but to no avail.  I would consider hooking up that heat tape to either an inverter or change over to 12V stick on heat pads for the dump tube, if you plan on driving in sub zero temps, so you can keep them running.  As for my fresh water feed tube freezing between the tank and the floor, I didn't come up with an elegant solution, we just disconnected the line and plumbed a new line to onboard 5 gallon containers, so we could at least use water to wash dishes and flush.  We just had to wait till the weather warmed up enough to defrost that section of tube.

[Grand Adventure]

2 minutes ago, dartmouth01 said:

Nice.  We have a similar pipe set up on our rig, the two main weak points I found after spending about a week in 0 degree daytime temps (some of it towing) last year was 1) the freshwater feed pipe to my water pump and 2)the exposed dump tubes.  The issues reared themselves not when we were sitting still, but rather when we were driving for hours and couldn't retain enough heat in the underbelly or pipes.  I have tank heaters as well, and we were running the furnace while driving, but to no avail.  I would consider hooking up that heat tape to either an inverter or change over to 12V stick on heat pads for the dump tube, if you plan on driving in sub zero temps, so you can keep them running.  As for my fresh water feed tube freezing between the tank and the floor, I didn't come up with an elegant solution, we just disconnected the line and plumbed a new line to onboard 5 gallon containers, so we could at least use water to wash dishes and flush.  We just had to wait till the weather warmed up enough to defrost that section of tube.

Excellent feedback -- thank you! I'd already thought of running off an inverter while traveling if necessary, but I hadn't expected the feed tube to the water pump to be an issue as it comes straight up from the tank. Is your underbelly enclosed and insulated?

[dartmouth01]

Yep, Forest River Sandstorm with "Arctic" Package, including insulation and sealed underbelly.  Water didn't freeze because of the tank heaters, but the feed tube did.  Dripping water would probably have avoided it, but didn't want to do that while driving.  Only option i can think of is trying to cut around the hole in the floor bigger to get more air to circulate around the tube, or dropping the tank to insulate the tube.  Alternatively, if you think ahead of time, disconnecting the tube at the water pump so the water will drain back into the tank, and hopefully leave the feed tube clear of water.   Anyways, the odds of us seeing those conditions again while driving so long (about 8 hrs at 0-10 degrees) will be low, so I'll just deal with it as it comes.

Oh, another couple weak points:  My low point drain comes below the belly, and will freeze.  It is attached to the lines that are below the floor and go to the separate vanity sink.  in the coldest temps, it would freeze and also freeze the junction to the vanity.  A quick hit with a hair dryer would solve that.  Next time I'll put a faucet cover over the low point drains and throw some insulation in it as well to try to avoid this from happening again.  Oh, and I had to replace the drain valve on my fresh tank, since it also sits below the sealed underbelly, and developed a slow leak after having too many freeze cycles.  The tank heaters would keep the whole tank from freezing, but the valve itself would freeze since it was exposed to outside air.

[Grand Adventure]

13 minutes ago, dartmouth01 said:

Oh, another couple weak points:  My low point drain comes below the belly, and will freeze.  ...Next time I'll put a faucet cover over the low point drains and throw some insulation in it as well to try to avoid this from happening again.  Oh, and I had to replace the drain valve on my fresh tank, since it also sits below the sealed underbelly, and developed a slow leak after having too many freeze cycles.  The tank heaters would keep the whole tank from freezing, but the valve itself would freeze since it was exposed to outside air.

More excellent advice thanks to your experience! I thank you sincerely. I didn't expect the fresh water tank drain to freeze if I was able to keep the tank liquid, but apparently I was wrong. I also wasn't too worried about my low point drains that are just like yours because, well...they're just low point drains. I suppose they could crack and split, but I'd think that the force of the expanding ice would merely run back up those tubes. I wonder if I ought to wrap those in heat cable as well? Or do you think that the insulated faucet cover would be sufficient?

[dartmouth01]

My low point drains froze repeatedly over the winter, but thankfully no issues.  The only time I had to address was when the ice went up high enough to affect the junction of the low point drain tube and the vanity feed tube, in which case hitting it with a hair dryer cleared it up pretty quick.  Usually only froze overnight, when the water sat for hours.  I'm skirted now for the winter (at Heavenly, waiting for it to snow!!) but if I were to travel in super cold weather, I'd throw a faucet protector and some fiberglass in it and cross fingers.

[Kirk W]

1 hour ago, Grand Adventure said:

I didn't expect the fresh water tank drain to freeze if I was able to keep the tank liquid, but apparently I was wrong.

I moved mine up to the inside of the RV, next to the potable water tank. It was outside where it not only was exposed to cold but also to dirt and grime from travel. Just put it at the top of the drain tube in place of the bottom. 

[Grand Adventure]

21 minutes ago, Kirk Wood said:

I moved mine up to the inside of the RV, next to the potable water tank. It was outside where it not only was exposed to cold but also to dirt and grime from travel. Just put it at the top of the drain tube in place of the bottom. 

That won't work for me. My fresh tank drain is mounted flush to the bottom of the tank. However, as is the case for Dartmouth01 it sticks out of the "enclosed" underbelly.

And Dartmouth, we Alta skiers are also playing the waiting game. Worst start to a season that I can remember, although they are letting us ski about half the mountain's acreage. Backside opened last Sunday and I was literally the first member of the public through the gate:

Skier: Dalles Keyes; Photo: me

[dartmouth01]

Nice!  I've been dragging my feet and only have been out a few times, but no excuses, living under the gondola and all.  :-)  

 

 

[Grand Adventure]

17 minutes ago, dartmouth01 said:

Nice!  I've been dragging my feet and only have been out a few times, but no excuses, living under the gondola and all.  :-)  

 

 

Score!!! Now my 17-minute drive to Alta/Snowbird/Brighton/Solitude will feel like an eternity. LOL!