Keeping Tanks from Freezing During Transit

I don't keep the gray onboard if possible, and I add a few gallons of blue windshield cleaner to the holding tank otherwise and dump frequently.

I also run the furnace going down the road and also when not going down the road to keep the camper up above freezing temps.

I put a small unit in my valve compartment...ran a 12v line and cigar plug (female)...all I do is plug in while moving, just remember to unplug when stop...don't ask how I know...the other way to remember to unplg is to put a 12v bed heat blanket in cabover it has LED reminder...yes don't forget to unplug that one too...but I tell you when you stop and it is 1* outside the warm bed feels so good. My tanks are in heated space so left furnace run at low setting...thing to remember is all you got to do is keep it above 32*. When I do my rebuild I will install a tank pad, just because I am doing a rebuild. All this made the travel in the cold much better.
12 v heat
Mine similar to red one..but yellow and got it a HF $13 works fine. Also insulated the door of that compartment and sealed air leaks around drain pipe and other places, stays dry now from road wash.

My tanks are heated with a duct from my furnace, so I don't have that problem.
People that do not have a heat duct usually have to dump them.

A few things that you could try and will help depending on the how severe the temps are :

Black tank....wrap the tank with some kind of insulation and use windshield washer antifreeze fluid to flush . you'll get a slushy mix but can usually still dump it .

If you use the gray water tank, you have to dump it before it freezes.

Keeping the wind off the tanks by insulating them , the trucks movement as well as the mixture of windshield washer antifreeze helps with complete freeze ups.
Carry a hair dryer , sometimes the dump valve freezes.

They also make 12 v pads :
Rv holding tank heating pads

another heating pad

more rv.net discussion on topic

Good luck ,

Bob

Unless your furnace directs hot air down into the basement such that all tanks and pipework are kept above freezing at all times (a big ask unless all holes are blocked and all hatch doors seal effectively and required insulation is installed correctly and is in all the right places which is doubtful) you might be better to start out completely winterised and use bottled water for everything including toilet flushing and add enough RV antifreeze to dose grey and black water as the tanks fill to keep them from freezing solid. Still need to run the furnace while travelling to keep the temperatures at least above freezing inside, but at least you won't have to worry about the water and waste system

Hi,

12 volt heaters are mostly pretty whimpy. They just don't produce many watts of heat.

If your tanks are in "heated space", just run the furnace.

Otherwise, winterize your water system.

We run our furnace in below freezing temps.

It would help others help you if you posted what kind of TC you have.

Wayne