It is one of the major concerns: what if the water freezes? In the meantime, it must be said that a compact block of ice in the tank is unlikely to be created, and then we need to clarify: which tank is it? Is there any action to take? We distinguish the different cases.
The clear water tank
The main one is generally in a bench in the dinette , therefore inside the camper and sheltered from the outside frost. Keeping the stove on all the time will allow you to have no worries. If you also have a second tank , usually external and not insulated and heated, do not use it and leave it empty . Keeping the stove lit will also repair the pump, the expansion vessel (if any), the boiler from any damage, and will prevent the Truma frostcontrol valve (for those with the Combi system) from discharging the contents of the boiler at due to the low temperature.
It may happen that in the morning water does not come out of one of the taps, this is because sometimes the canalization does not run close to the system or the latter passes too close to some grid or wall. For example, it could happen that the system passes behind the fridge in correspondence with the ventilation grilles . In these cases , the first step could be to insulate the pipes with a strip of neoprene , but the best thing is to make (or have made) a small deviation from the pipe (I'm talking about the section of the pipe), with a Y-fitting or T, and better heat the part where the pipes pass .
Remember : when you leave the camper, at night, when you travel and in general when you don't use the water, always turn off the water pump , this is a good habit to keep at all times, in any season .