It could be that other deductions and credits have reduced your tax to $0 already. You can check for this by looking at the total tax on your tax summary.   Here is how to do that:

1. Log in to your tax return at TurboTax.com.
2. Click on Tax Tools on the left side of the screen (you may need to click on Continue in the center first).
3. Click on Tools.
4. In the box that pops up in the center, click on View Tax Summary.

Thank you for the response, but no the tax burden is not $0. Does the IRS subtract the home energy tax credit when they receive the filing and then, for instance, I would not get a charge at all from them once they've subtracted the credit from the amount due? Or should the Turbotax Federal amount in the browser window reflect the amount due AFTER the home energy tax credit? Our Federal amount in the browser did not reflect the home energy tax credit.