HTP Phoenix is an efficient and versatile gas-fired water heater that is manufactured with super durable stainless-steel materials to last longer and provide optimum heat transfer. The Phoenix offers up to 96% thermal efficiency and a 5 to 1 turndown ratio. The unit is laser welded and constructed with a 316L stainless steel tank to resist corrosion and includes a heat exchanger that eliminates scale build-up and promotes self-cleaning, the company states.