Our 631 series is perfect for homes with 1-2 showers.  When properly sized, they provide an endless supply of hot water to an entire home.  With state-of-the-art gas combustion technology, Noritz burners maximize output and provide temperature stability while maintaining low emissions.  Built-in features include safety lock-out, freeze protection, and high elevation adjustment.  These units also offer several innovations:

Safety lock out - Default max. 120 degrees (refer to owner's manual for higher temp)

Fully modulating burner - Automatically adjusts burner level accordingly.

Turbo Flow - Up to 7.1 GPM @ 35 degree temperature rise (6.3 GPM @ 45 degree rise).

Direct ignition - No standby pilot light.

Thermal fuse - Automatic overheat protection system.

Resin coated PC board - Increases durability and protection from elements.

Automatic air regulator - Monitors internal temperature/maximizes burner efficiency.

Resin coated PC board - Increases durability and protection from elements.

*Energy Factor (EF) is a measurement of relative energy efficiency for a water heater; the higher the EF, the more energy efficient the water heater.