When forced to burn his own house by Chief Beatty, Montag feels conflicting emotions. He is sorry to burn the books, sorry to burn his house itself in some ways because it still has happy memories for him. He is also filled with rage about being turned in by Mildred and filled with angry joy at being able to destroy the parlour television screens, which he hates so much.
And as before, it was good to burn, he felt himself gush out in the fire, snatch, rend, rip in half with flame, and put away the senseless problem. If there was no solution, well then now there was no problem, either. Fire was best for everything!
(Bradbury, Fahrenheit 451, Google Books)
He returns, in a way, to the joy he took in burning at the beginning of the book, but does not have the visceral reaction he had to burning books themselves; instead, he feels the need to destroy everything, since everything -- not just television, not just books -- is part of the problem. The burning is liberating because everything that ties him to the city is destroyed; it is emotionally trying because he feels a connection to the books; it is joyous because he is finally able to escape convention and conformity and do something wrong in public, without condemnation.
Montag remains emotionally detached in this section. He enjoys burning his own house as much as he enjoyed burning those of others, and he begins to agree with Beatty that fire is removing his problems.