Several members here have played with or installed tank-less water heaters. A Search will uncover the discussions. Use the Search bar up near the top next your your name. I used the terms tankless water and got some good hits.
This Thread is a good start with a link to a You Tube vid on installing a Fogatti WH
https://www.montanaowners.com/forums...ad.php?t=86398
This is a Thread about a different type tankless but it has install pictures.
https://www.montanaowners.com/forums...ad.php?t=85412
And then there is this Thread:
https://www.montanaowners.com/forums...ad.php?t=78659