Hello
The tax guidance for home energy credits is incorrect. It states that the credit must be used on your main home. This was changed in 2024 to reflect that it could be used for second homes as long as they were not rented out or used for business purposes. This was the case for us as we purchased a new woodstove and a heat pump for our second home and wish to make use of these credits.
from the IRS form(see below)
You may be able to claim a credit for certain improvements made to a second home located in the United States that you live in part-time and don't rent to others. You can't claim a credit for fuel cell property for a second home or for a home that is not located in the United States. Find more on qualifying residences.