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Motorhome in winter, The gray water tank

Also for this, no problem if you have insulation and heating, but lubricate the drain valve anyway with a silicone spray and, if necessary, a de- icing spray . If, on the other hand, the recovery tank is not protected, there are at least three schools of thought:

  • an antifreeze liquid

  • salt

  • an outdoor bucket

Motorhome in winter, The gray water tank
Motorhome in winter, The gray water tank

I say right away that I'm not for any of these , I'll explain why.

Put some antifreeze liquid in the tank. DON'T DO IT, it's highly polluting . I have nothing more to say, for me it is not a solution, ever.

Salt dissolved in water lowers the freezing point . Consider that sea water freezes at about -1.7 degrees Celsius. It doesn't seem like a lot of gain , so you have to increase the density. Just to make a learned quotation , Galileo Galilei had already observed in 1600 that a solution of two parts of water and one of salt froze at -20 degrees . I have read, but not experienced, that a 6 to 1 solution (water to salt) would allow water to freeze at -14degrees. 8 kilograms of salt per half tank of gray water (50 litres). Let's say our water is soapy, so it resists the cold more, let's say it's hot when it reaches the tank: is 4 kilograms enough? Maybe 3? And do the gaskets and metal elements of the guillotine get damaged in contact with a saline solution? Honestly I have NEVER adopted this solution.

Place a bucket under the tank drain valve , keep it open and empty the bucket frequently. Meanwhile, if we are free this is prohibited by the CdS , then it is not decent (how disgusting these campers, they pour sewage in buckets outside the campers), therefore, possibly, only in the campsite or in a private parking area. But there is a risk that the dirty water will overflow and form a layer of ice under the camper, after dinner, in the warmth, we won't feel like going out to empty the bucket, and the little water that could end up there during the night, the tomorrow it will be a block. In short, perhaps the bucket could be an emergency solution like "in real time", I put it on while I'm using the water and take it off as soon as I finish. This, for me, is not a solution either .

Then? For a weekend, even a long one, leave the water in the tank, as soon as you leave to return, the tossing and the rising temperature will slowly melt everything, at the Camper Service, you will empty it as soon as possible . And in other situations? For frequent and long outings? For temperatures several degrees below zero? Insulate, it's the only one. I'll talk about it in a bit


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