There is a large puddle of water under my motorhome?

In the category The living area of the van
The Frost Control is probably the cause. The Frost Control ensures that the water heater will drain in colder temperatures (4 -6°C) to prevent the water from freezing and causing irreparable damage. In this case, it is advisable to turn on the heating so that the motorhome warms up. Then you can close the Frost Control and refill the water heater.