If you are looking to buy a second-hand camping vehicle or hire a vehicle, please note the following with regard to the gas supply:
Carefree holidays with hired vehicles. XXX
Always check that the gas system has been tested and has a valid gas testing certificate. This testing certificate may only be completed and signed by a gas expert. In addition to the testing certificate, a test plate in compliance with G607 is attached to the outside of the vehicle, assuming that it has passed the inspection (see figure bottom right).
Also check whether the gas system can be operated whilst the vehicle is driving. If there is no safety lock (like the Truma crash sensor) in the vehicle, the heating cannot be operated when on the road.
Gas test plate attached to the vehicle
In this case the valves on the gas cylinders need to be closed. A warning sticker attached to the gas cylinder box states that the gas cylinders need to be closed when the vehicle is on the road.