Home Energy Credit is incorrect. Should be $300 (according to https://www.energystar.gov/about/federal_tax_credits/water_heaters_non_solar) but only get $150.

I installed a qualifying water heater in 2016, and the credit should be $300, but TurboTax doesn't seem to properly factor in that credit from form 5695 and instead indicates credit would only be $150.  Waiting to complete my filing until I have a better understanding of what I should do.  Thanks!