Winter Use of our T@B

Interesting idea. Just a word of caution though, @gregp, cuz I'm a little curious about how the antifreeze would get inside the gate valve with this method.

When I learned this particular lesson about the gate valve, water had worked its way into the works of the valve, the place that the blade pulls back into. 

Then when the water froze, it expanded and cracked that 'blade housing'.

Sharon_is_SAM said:

@gregp. Somewhere I read that you can use a spray bottle filled with antifreeze and spray the gate valves(s) of the tanks.  That would be an easy fix.

Wouldn't this solve the issue with water lines freezing?
https://www.campingworld.com/freeze-ban-heated-drinking-water-hose-25?CAWELAID=120030630000000649&gclid=Cj0KCQiAurjgBRCqARIsAD09sg_aMpCDCPO_fiM14Kwuwc0uhyslgSvddapCv7eujWbw7n_iEm72HFsaAgvZEALw_wcB

Just camped in freezing temperatures and used the heated garden hose Steven recommended above (I was connected to city water).  Also poured 1/2 gallon of RV anti-freeze down the black and grey tanks each.  Camped for several days and used the sink, toilet and shower without any problems.  Dumped when the temps were somewhat mild without any valves sticking.  However, I'll be following Greg's lead and adding an Alde convector to the undercarriage to heat the fresh and grey tanks while boondocking.  By the way, the folks at Alde USA are VERY helpful and consumer-oriented.  Unfortunately, none speak with a cool Swedish accent.

Awca12a:

I don't plan on camping anywhere with freezing temperatures during the day, so I won't go as far as Greg by adding an insulated "basement." Also, I don't want to do anything to decrease ground clearance.  I looked at the heating pad idea first, but now may use both based on your comments above.  Electric heating pads while traveling and Alde at the campsite.  The fresh water drain tap and sewer valves still need a viable solution to keep them from freezing.  Perhaps some electric heat tape and a DIY cover that can be put on at the campsite?  

There's actually plenty of room for the Alde convector in front of the fresh water tank and next to the grey waste tank.  Just lower the front portion of the coroplastic sheet covering the undercarriage to take a look.  In addition, there appears to be about 1/2" to 3/4" of space between the bottom of the fresh water tank and the top of the coroplastic.  This would allow a sheet of thin insulation to rest on top of the coroplastic.  The large axle inspection holes on the frame behind the tires would also need to be sealed.  Please send a link to those elbow pads.  With that low wattage, they could easily be used when boondocking.

Here are a couple of ideas from the newsletter RVTravel.net regarding prevention of plumbing freeze.  These involve stationary RVs.

@Tabaz you’ve got me thinking of doing the same.  To make that happens I guess you’d have to find the last convector in the line and then tap into it.  According to this factory tour video that last convector is under the shower.  I’m not a plumbing guy.  How would you add that additional convector?
https://m.youtube.com/watch?v=if066aMnC2U

Awca - I have a 320 (similar to Greg). I would be tapping into the convector under the passenger seat pedestal like he did. So glad I just saw Greg's post above.  He's using a "mini" convector and its more than enough for the tank area.  Alde is out of the mini's, so I almost bought a regular convector for that area.  That would obviously be over-kill.

@gregp, I'm surprised that you can only get it up to 60°, with those outside temps.

I see you don't have the fridge vent covered (next to the door). We found that to be a big source of draft, especially in the wind. (It's for the fridge 'waste heat', which you might as well not waste!)

Also in ours there was a large gap (drafty) between the insulation and the outer shell, under the back shelf, which I taped up with aluminum tape (really sticky).

Also, around the AC unit was drafty.

Those fixes made a big difference for us. 

@jkjenn yes the idea was to be able to use fresh and grey water systems in the winter.  Actually got down to 8 degrees last night and no problems, even took a shower.  @ChanW thanks for the insights on the fridge vents, I had no clue we could cover those so will give this a try. Did you cover both vents?  Also I have had to bleed air from the Alde system a couple of times to avoid an airlock but I think that issue is now resolving.  Also thanks for the identifying gap issue between the insulation and the outer shell behind the back shelf, I am going to pull the shelf out and see if I have the same problem.  I do have the AC unit opening fully sealed and have replaced it with a microwave.  Hopefully all of the this will help!  Thanks!  Also @Tabaz did you go ahead and enclose your tanks yet?  Am curious how the project went? Drop me note if I can be of any help!

Greg

Thanks again to grepP for being the first to trailblaze this mod.  Here's where I'm at today.
Photo of the Alde floor mesh that dissipates heat from the Alde floor heating system (see their parts catalog).  Using PEX flexible pipe from Home Depot instead of the Adle pipe (only comes in HUGE rolls). Did a test with very hot water and the red pipe got very warm, so should heat the aluminium mesh.  The mesh will be wrapped around the PEX pipe next to the valves (next photo).

The PEX "loop" on the inside of the grey and black valves.  Red arrow is my cable-activated grey valve (non-factory).  Yellow arrow is bottom of black valve.


Bottom view of the Loop.  Yellow line follows the standard Alde rubber hose around the grey tank.

Top view of the Loop. Pipe is very flexible, so should huge the ABS pipe pretty well.

New mini-convectors at rear of trailer frame looking towards front of T@B.  Blue arrow is convector, yellow is new hole for new Alde hose, grey arrow points to back of fresh water tank. 

Two mini-convectors along the driver's side of the T@B.  Grey tank is to the left. This shot faces the rear of the trailer.

Rear convector with Alde hose clip (red), New hole into the cabin (not metal brace to left of yellow arrow), existing propane line into the cabin (blue).

The new "basement" convectors continue the factory "loop" in the cabin.  The PEX hose forms a sub-loop in the main hose line.  Still need to figure out how to cover the PEX loop with the aluminum mesh.

Attached is their parts catalog.  Speak with Mandy at 360-597-3017.  She is very helpful and a joy to work with.  No ground clearance lost with this mod.  I'll be adding 1/2" of foam board on top of the existing Colorplast belly covering.  I think I've found a way to swivel the fresh water tank drain up so that it no longer hangs down off the frame (it will now live in the heated basement).  It will be covered with an insulated 4-gang electrical cover.  Photos to come when I get that far.

I'm thinking of incorporating a 3-way valve so I can manually, divert fluid into a separate basement heating loop, or not. No sense wasting heat there if no freezing temps or not carrying fluids. I'll have a remote temp sensor down there. All theoretical so far as I've barely used my new T@b so far.

First test of the "basement heater" was a success.  The Alde hose and 4 mini-convectors generated a good deal of heat (considering its 85 degrees now in Phoenix).  Once the underbelly is insulated and covered, no way will the grey or fresh tanks freeze.  I didn't realize the Alde rubber hose generates heat in addition to the convectors, so another plus there (i.e. the entire perimeter of the basement is generating heat).  I was a little disappointed with the heat generated by the 1/2" red PEX tubing.  Will definitely be replacing the PEX with the larger Alde hose.  Once enclosed, I can't see the black or grey drain valves freezing.  Thinking of making a valve enclosure out of Coroplast with magnets that attach to the metal frame - only to be used at the campsite.  Any enclosure ideas for this area would be appreciated.