If you have not completed the rest of your return, or have no income tax liability this may be why the credit is not appearing. Self-employment tax is not included as income tax for purposes of this credit. The energy credit is non-refundable, so if you don't have enough income tax being computed, the credit won't be generated.
If you have entered all your income, and still are not getting a credit, be sure you have entered your information in the correct place in TurboTax Online:
1. Upon opening TurboTax, choose Deductions & Credits
2. Locate Your Home
3. Start/Revisit Home Energy Credits
4. On the Energy Efficient Home Improvements screen, select Yes then Continue.
5. Answer the next few questions until you get to Did you have any of these residential energy property costs in 2024? Heat pumps are listed here. Select Yes and continue.
6. Make sure you enter the total cost and answer the questions about ownership and location of the home.
See this article for a summary of the amounts available: Energy Efficient Home Improvement Credit (EEHIC)