Oasis Concepts Diesel and AC Heating System for Recreational Vehicles and Yachts - Manual (Page 43)

Plumbing the System
7.1 Before You Begin
For efficient and safe operation of the Oasis™ Heating Module,
follow all recommendations for properly installing the plumbing
system. Any deviations from these must be approved in advance by
ITR.
The Oasis™ Heating Module when attached to the Distribution
Module (optional) must use the following:
Section
7