Heated Tanks

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whaler23

Member
Joined
Jan 15, 2006
Posts
10
Hi guys it's been a while since I have posted.  My '99 HR Vacationer is parked in MD all winter in my driveway.  As I will be using it about twice per month this winter I am not planning on winterizing it.  My question is how do I tell if my tanks are heated, I have no indication they are from the owners manual and original window sticker.  Looking underneath the rig they are heavily boxed in with insulation (some type of foam looking material that hardens once sprayed like Great Stuff) then it was sprayed over with undercoating.  My plan was a electric liquid filled radiator in the living quaters and a small ceramic heater in the sewer bay set on about 45 degrees to keep things from freezing up  My problem is the tanks.  Any advice is appreciated.  Thanks.
 

Alaskansnowbirds

Site Team
Joined
Mar 11, 2005
Posts
2,985
Location
Camp Verde, AZ
whaler23 said:
Hi guys it's been a while since I have posted.  My '99 HR Vacationer is parked in MD all winter in my driveway.  As I will be using it about twice per month this winter I am not planning on winterizing it.  My question is how do I tell if my tanks are heated, I have no indication they are from the owners manual and original window sticker.  Looking underneath the rig they are heavily boxed in with insulation (some type of foam looking material that hardens once sprayed like Great Stuff) then it was sprayed over with undercoating.  My plan was a electric liquid filled radiator in the living quaters and a small ceramic heater in the sewer bay set on about 45 degrees to keep things from freezing up  My problem is the tanks.  Any advice is appreciated.  Thanks.

If the tanks are empty you don't have to worry about anything freezing. With the insulation you describe I would think it would take below freezing temps for over a day before you would have to worry.

IMHO
 

Gary RV_Wizard

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Joined
Feb 2, 2005
Posts
74,339
Location
At our Silver Springs FL home
If there is no switch or control for "tank heat" or some such, the tanks are most likely "heated" simply by the existence of an air duct down into the subfloor area. Usually not too effective even if the interior is kept at livable temperatures. The air simply doesn't circulate that well.

But the tanks are rarely the issue anyway. If more-or-less empty there is nothing to freeze and plenty of room for expansion if it does. Water lines to/from the tanks, water heater, valves, ice maker lines, etc. are the potential problem.  There is often residual water in them (even if drained) and a small amount of water can readily freeze and, if trapped in a small area, the expansion will break something. The area with the dump valves is one exposed place with water likely sitting inside, so providing a bit of heat there is goodness. A 75-100W light bulb does wonders on a icy night if the dump valves are in an enclosed bay - will keep the entire area above freezing.

Turn the water heater on in the evening to heat it up if a hard freeze is expected. Or drain the water heater if there will be a couple days below freezing.

Inside the rig, open cabinet doors and drawers to let convection circulate the warmed air closer to walls and other places where water lines are draped or buried.

Pour a bit of antifreeze into the drain traps and toilet bowl just to be safe - it only takes a second. Use the pink, potable water type cause automotive antifreeze is hard on plumbing. Or use some alcohol. It doesn't take much to get the freeze point down to 20 or less and that should be adequate for your area.

If you have an ice maker, the water line to it can be a problem. Recent fridges have a heater on the line that is powered off shore power, but older ones can freeze. I used a 15W light bulb in the access area at the back (outside) of the fridge when we had one of those and encountered the odd below freezing night here in central Florida. It kept the area just warm enough.

 
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