There is a smaller underfloor grey water tank,draining from the kitchen and washroom sinks,but the shower tray drains direct to the ground (or a bucket)
(to the left)
Fresh water tank
(to the right)
The Truma Ultrastore water heater.
This had to be raised on a plinth to allow the flue to exit above the plastic external trim on the wall outside.
This left room for the Shurflo pump to be fitted beneath.
The pipes are colour coded-red for hot,and black/blue for cold.