We have had a good 15 years from this unit, and our plumber informs us that a slow gas leak is the problem, and given the life of the unit, we would be best served to replace it. We have a small one-bathroom home requiring pipe upgrades (due to old gal pipes). We love the continuous hot water model that we have been used to, so what replacement model is recommended? Like for like, is the Bosch 16P the same unit only re-badged/ rebranded?