Looking for a new water heater? Matt Risinger shows off the AO Smith Vertex 100-gallon gas water heater and lets us know about the three things that separates this beast from other water heaters. The water heater can hold 75 gallons, has a 100,000-BTU burner, and some other cool features like the recirculating tap and the heater's ability to do space heating. The top three things he specifically likes about this unit Efficiency. This unit is 96% thermally efficient and a .8 on the uniform energy factor. Power. With this unit's storage capacity and huge engine, it can output four gallons per minute without ever slowing down. Performance ability. The concentric vent is so cool that you can use spray foam to seal the envelope. Learn more in the video.