Yes, the S 5004 can be installed in the position of the old heater if it is an S 5002 built after 05/98. With older models, the floor cut-out must be changed.
Remember that the control panel carrier is higher due to the new cover and that the cupboard door may have to be modified in some cases. The contour and, hence, the depth of the floor base have also been changed slightly – as a result, you may see the impression of the old base on the floor. Because it has a lower installation cut-out, when you install a Truma S 5004 you have to use a spacer so that the heater works properly.
When replacing, please see your nearest Truma dealership.