- Showing 1 - 36 out of 180 results for "rheem-ruud commercial gas water heater%2c 100.0 gal tank capacity%2c natural gas%2c 199%2c900 btuh - water heaters model%3a gnu100-200"Sort by:FeaturedProduct added to your wishlist! View wishlistSign in to see your saved products on any deviceProduct removed from your wishlist! View wishlistSign in to see your saved products on any deviceSomething went wrong. Please try again later.Product is added to compare already. Please refresh the page.Product is not found in compare. Please refresh the page.5 Products already added. Please delete existing selection to add this.