A History of Innovation

Bock is committed to supplying the highest level product quality and service built around industry leading product innovations. This innovation commitment is part of Bock’s heritage. From our breakthrough in heat conduction and fuel efficiency with our Turboflue helical-fin heat exchanger, to leading the industry in first to market modulating water heaters with our OptiTHERM. And this commitment continues today with our recently launched Outdoor OptiTherm to maximize space in climate acceptable areas, to our new line of ElectriTherrm Heavy Duty Digital Electric Water Heaters.

Bock, committed to product innovation…committed to quality…committed to service…committed to you.


Bock OptiTHERM provides up to 99% Thermal Efficiency by modulating fuel input to supply variable domestic hot water demand. These first to market modulating condensing water heaters in sizes 125,000 to 500,000 BTU provide up to 25% annual saving over regular water heaters. With an automatic cathodic protection system that is virtually maintenance free, LCD user interface for easy set up and monitoring and five year warranty, it is no wonder OptiTHERM is the product of choice in commercial applications everywhere. OptiTHERM, your choice for Optimal Thermal Efficiency and Savings.

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OptiTHERM® Outdoor

Industry leading innovation from Bock…New OptiTHERM Outdoor, providing the same high efficiency, performance, quality and five year warranty of OptiTHERM, now in Outdoor models from 125,000 to 500,000 BTU. Minimize the need for space in your utility room in climate acceptable areas.


Turboflue helical-fin heat exchangers utilize hundreds of steel fins, engineered in a precise spiral design, to provide superior heat conduction and fuel efficiency. This patented maintenance free technology is the cornerstone of the exceptional thermal efficiency levels found across Bock Water Heaters.


The latest in Bock’s line-up of high efficiency, state of the art water heaters, ElectriTHERM utilizes a digital control system with LED diagnostic readout for exacting temperature settings and status. With immersion thermostat for superior set point accuracy, ElectriTHERM exceeds all standards for DOE standby loss. Dual cold inlets allow for ease of installation, thickest steel in the industry, and incoloy elements provide superior corrosion resistance and is why we offer a five year tank warranty. Simple ordering allows you to easily choose your correct tank size (50, 80 and 119 gallon), kW, voltage and field conversion kits.