@jjmillerx21 the tax liability is Line 22..... that line can be reduced to no lower than zero by the heat pump tax credit (that is what is meant by "non-refundable").
the payments section doesn't change (lines 25-33) so the result on Line 34 can be a larger refund (because line 22 is reduced to zero).
there are other tax credits that are 'refundable' meaning that Congress is adding to the payment section on your behalf.