Thanks for the reply.
From the IRS pub, this is what I am reading. The bold line shows that it should be 30% of the cost, up to a maximum of $1200. So, I'm still a bit confused how you are getting $600.
======Pasted From the IRS Link=====
These expenses may qualify:
- Exterior doors, windows, skylights and insulation materials
- Central air conditioners, water heaters, furnaces, boilers and heat pumps
- Biomass stoves and boilers
- Home energy audits
The amount of the credit you can take is a percentage of the total improvement expenses in the year of installation:
- 2022: 30%, up to a lifetime maximum of $500
- 2023 through 2032: 30%, up to a maximum of $1,200 (heat pumps, biomass stoves and boilers have a separate annual credit limit of $2,000), no lifetime limit
