The T-M32 was developed specifically for commercial applications.  The T-M32 offers many benefits including the following: 

240,000 BTU/U, up to 9 GPM (Max)

The versatility of being installed either indoor, outdoor, or with a direct vent, all with the same unit.

Easy-link capability up to 4 units.  You may connect up to 20 units and generate over 180 GPM using a multi-controller unit.

Uses HRS copper, the most durable copper in the industry.  HRS copper is stronger and harder than the standard copper, making it much more resilient against erosion and leaks.

Offers precise control of the water valves.

8 new dipswitch temperature settings: 100 F, 115 F, 120 F, 135 F, 145 F, 155 F, 165 F, and 185 F.  These temperatures are better suited for commercial applications.

7-segment LED for error codes:  Remote controller is not required to pinpoint problems.

Ignition indicators: indicates which burner is fired up at the moment.

Utilizes the air-fuel ratio rod for added safety.

The drum thickness has been increased 25% for greater heat exchanger performance and to be more resistant to thermal stress. 

Increase in fin pitch:  Fins are more "spread out" which improves the durability of the heat exchanger. More space in-between the fins reduces build-up.  Higher temperatures at the top of heat exchanger reduces condensation.

ASME version is coming soon.