Phase III's exclusive design allows for the continuous production of domestic hot water without the use of a coil. Hot water from any boiler is circulated around a corrugated stainless steel tank for safe, efficient hot water at the lowest possible operating cost.
Featuring a Lifetime Warranty - See warranty certificate for full warranty information

Superior Design "Tank-inTank" Technology

When combined with any boiler, Phase III models TR and HL series indirect water heaters provide the most efficient hot water heating systems available today. Phase III's advanced technological design features two concentric tanks: an inner tank, constructed of 100% high quality stainless steel, contains domestic water. The outer tank, constructed of durable carbon steel, contains boiler water. Water in the inner tank is heated indirectly by circulating hot water in the outer tank from the boiler.

The unique surrounding heat exchanger provides a much more even distribution of heat as compared to a coil type heat exchanger.

Indirect water heaters with coils are more susceptible to isolated cold spots in the domestic hot water tank which can lead to bacteria growth. Coil heat exchangers are also more susceptible to liming. These conditions do not exist with the tank-in-tank design.