Hi cavetter,
Welcome to the Heartland Owners Forum and to the family. We have a great bunch of folks here with lots of information and all willing to share their knowledge when needed.
I suggest you call Heartland Customer Service, 574-262-8030 or 877-262-8032, have your VIN when you call. They can tell you for sure I would think, but almost all units as a standard have a 40 gal capacity fresh water tank.
Be sure and check out our
Heartland Owners Club. Join us at a rally when you can and meet lots of the great folks here and make friends for a lifetime.
Enjoy the forum.
Jim M