Replace leaking Navien unit with warranty unit. Disconnect all plumbing from old tankless and removed from crawl space. Mount new warranty unit in place and reconnect plumbing. Condensate drain was backpitched so we corrected that. Also extended exhaust line out of house and moved up 18†to create proper spacing between exhaust and intake. Turned new unit on and bled fixtures and test for hot water. Everything is in working order at this time.