Heated Chamber for Waste Valves

[MSL]

I've seen a lot of posts for frozen waste valves and ways to thaw them. I've seen a couple of posts using 12-volt heat tape to preempt freezing (they mention it doesn't work so well to defrost an already frozen pipe/valve).

I'm wondering if anybody's built and insulated box around their waste valves and run a furnace duct into this box; much like Airstream does with the holding tanks.

Just wondering how that might work.

Mark

[Steamy1]

RV gate valve heater pads are available. I personally do not have any experience with these, but maybe Tim A can comment.

[MSL]

Originally Posted by Steamy1

RV gate valve heater pads are available. I personally do not have any experience with these, but maybe Tim A can comment.

Yes, but these use additional power. If done via the furnace, you wouldn't be using additional power

[Al and Missy]

Maybe I misunderstand, but doesn't the furnace heat the tank area and wouldn't that heat the valves? My classic has a tank pan around the gray and black tanks and the valves are inside the pan with the tanks. Maybe it only heats the fresh water tank pan, which is separate.

[Tim A.]

Some Airstreams have the valves enclosed and some don't. The drains and valves from the gray- and black-water tanks are completely exposed in our trailer. That's why we have the 12 V heating pads on those drains and valves. The pads work well, but are not what MSL wants.

Tim

[MSL]

Originally Posted by Tim A.

Some Airstreams have the valves enclosed and some don't. The drains and valves from the gray- and black-water tanks are completely exposed in our trailer. That's why we have the 12 V heating pads on those drains and valves. The pads work well, but are not what MSL wants.

Tim

Correct. My Sport 22 also has the valves exposed.

I'm hoping for a solution that doesn't use extra power so I can use it if I'm boondocking 1 or 2 nights. The heat tape would probably use 4+ amps, which would deplete one of my 2 Li batteries I'll be installing in a full day. They say the heat tape works for stopping freezing from occurring, but not great for defrosting once it happens.

Thanks, Mark

[Silvr_Bullet]

There’s no room to fashion a box around the exposed dump valves and handles. Even if you could I don’t think there’s an insulating material alone that would prevent freeze ups in -F temperatures.

[Tim A.]

Originally Posted by MSL

Correct. My Sport 22 also has the valves exposed.

I'm hoping for a solution that doesn't use extra power so I can use it if I'm boondocking 1 or 2 nights. The heat tape would probably use 4+ amps, which would deplete one of my 2 Li batteries I'll be installing in a full day. They say the heat tape works for stopping freezing from occurring, but not great for defrosting once it happens.

Thanks, Mark

I have posted on other threads that we use the heat pads (ours are Ultraheat) only when we are hooked up to shore power. We still have a single AGM battery and the pads would drain it in an hour if we weren't hooked up.

The pads will eventually defrost everything, but it takes some time. We have separate switches for the pads on the pipes, the valves, and the water inlet (ours is exposed). That way we can select what we heat.

Tim

[MSL]

Originally Posted by Tim A.

I have posted on other threads that we use the heat pads (ours are Ultraheat) only when we are hooked up to shore power. We still have a single AGM battery and the pads would drain it in an hour if we weren't hooked up.

The pads will eventually defrost everything, but it takes some time. We have separate switches for the pads on the pipes, the valves, and the water inlet (ours is exposed). That way we can select what we heat.

Tim

Any idea how long it would take to defrost? I know there are a lot of variables, but any idea at all? Do you put insulation on the outside of the pads?

I currently have 2 AGMs but am putting in 2 Li 100Ah prior to a southwest trip we're doing in March/April. I know they'll do better, but I wouldn't want to leave them on 24 hr/day. We also plan to do provincial parks in the fall when it can get cold, and electric is frequently not available in them.

I think the idea of a chamber with a heat duct makes sense (it looks to me like there's room in my trailer), but it's a fair amount of work for something I may never need. I've camped when it's been down in the 20s overnight, and the only problem I had was the valves ... it was not fun out there with a hair dryer when I wanted to hit the road.

Thanks for the info. Mark

[Tim A.]

I have never checked on how long defrosting takes. If we are going to leave after a freezing night, we dump the day before when temperatures are above freezing. Freezing days we try to avoid!

The pads for our tanks and valves are not insulated. For our water inlet, we made a small, somewhat insulated enclosure and the heating pad is inside that. The inlet pipe is up against the trailer's steel frame by the bumper, so not much that insulation can do! Sounds like a stupid arrangement for the inlet and, yet, we like it.

Tim

[MSL]

Originally Posted by Tim A.

I have never checked on how long defrosting takes. If we are going to leave after a freezing night, we dump the day before when temperatures are above freezing. Freezing days we try to avoid!

The pads for our tanks and valves are not insulated. For our water inlet, we made a small, somewhat insulated enclosure and the heating pad is inside that. The inlet pipe is up against the trailer's steel frame by the bumper, so not much that insulation can do! Sounds like a stupid arrangement for the inlet and, yet, we like it.

Tim

Good thoughts. Thanks, Tim

[dsatwork]

I don't understand your logic, you want to boondock in subzero weather and dump which tank where?

[ASFC25_2019]

Once valves are frozen, they can take some time to open up. So, figure dumping might be an issue for a while. I have to use a portable heater to get these valves to open. It takes some time. I have been debating adding a heat option. Thank you. I might use the ultra heat https://www.ultraheat.com/retofit-rv-drain-pipes

[MSL]

Originally Posted by dsatwork

I don't understand your logic, you want to boondock in subzero weather and dump which tank where?

Subfreezing, not subzero F. I just don't want the exposed piping to freeze. Dump later, someplace else. Or maybe I'm at a state or provincial park without power, but they have a dump station. This doesn't make sense?

[PaulBristol]

Originally Posted by MSL

Subfreezing, not subzero F. I just don't want the exposed piping to freeze. Dump later, someplace else. Or maybe I'm at a state or provincial park without power, but they have a dump station. This doesn't make sense?

Dumping in Winter

Dumping north of St Louis is always a problem in late fall through early spring. Different campgrounds close dump stations at different times.

Wisconsin State Parks remain open, but close dump stations and enforce closure. I found a municipal dump station that is closed, but not supervised. I bring enough water on-board to do all the flushing needed.

Enclosing Dump Valves

Enclosing dump pipes and valves is possible. It depends on how long they are as to what extra heating is needed. Some trailers have the dump valves remotely controlled and inside the heated belly. Some do not.

Short pipes can get enough heat from the liquid in the tank as long as the exposed parts are insulated and covered to protect from slush, snow, and ice. This worked successfully in my last trailer that had 1 foot of pipe below the belly. I have not yet enclosed the pipe and valves on my Trade Wind.

In order to keep dump valves working in empty tanks during freezing weather, you can protect them by dumping a gallon of RV antifreeze into the drained tank. Hopefully there is little to no water in the tank.

I do pack a hair dryer. I used it once. I was testing the new trailer in my driveway. A pipe inside the "enclosed and heated" underbelly froze within four hours of 28 degree F temperatures. I needed the hair dryer to thaw low point drains and dump valves in order to quickly winterize the trailer.

Now, plumbing remains winterized unless I have a tested solution. It cost me $200 to replace a water pump. I cannot imagine the possible damage to frozen pumps, pipes and other fixtures. Even small leaks can cause serious water damage.

It cost about $3000 and three years of part time DIY work to winter proof an "All Season" Dutchmen Kodiak Cub. After that, we frequently camped in temperatures down to 15 degrees F with no issues.

Freeze damage is specifically excluded from warranty.

[dsatwork]

Originally Posted by MSL

Subfreezing, not subzero F. I just don't want the exposed piping to freeze. Dump later, someplace else. Or maybe I'm at a state or provincial park without power, but they have a dump station. This doesn't make sense?

Sorry I must have been really grumpy when I wrote that or tired of being cold after going to Portland for a week and dealing with cold dumping myself. It only got to 29 but I never had trouble with the gate valves because typically by the time I was dumping the temperature was rising or the sun was out helping. The dump valves I have heard and seen on videos can freeze even on the inclosed ones. I know that I could Tee off the hose going to the bathroom in our 30 and route it to that area because they are on the same side.

[MSL]

Originally Posted by dsatwork

Sorry I must have been really grumpy when I wrote that or tired of being cold after going to Portland for a week and dealing with cold dumping myself. It only got to 29 but I never had trouble with the gate valves because typically by the time I was dumping the temperature was rising or the sun was out helping. The dump valves I have heard and seen on videos can freeze even on the inclosed ones. I know that I could Tee off the hose going to the bathroom in our 30 and route it to that area because they are on the same side.

No problem. I'm just looking for something passive to keep my valves from freezing when I don't have shore power. I have a trip coming up and I'll probably throw some antifreeze in the pipes if I need to. I'm still thinking about making a box around the valves though ;-) I had to do the hair dryer thing once and hated it.
Mark