In the book of Kings all you really see with King Ahaz (the father of Hezekiah) is that he found a nice altar in Damascus and then asked Uriah the Priest to build one like it in the Temple. But in Chronicles it took the priests and Levis two weeks to clean out the Temple when Hezekiah began his reign. That seems to indicate that the whole Temple area was completely unusable. Also you can see this from the fact that Hezekiah did not want to bring the Passover in uncleanliness as he could have if the Temple had been usable.[ Instead he made the 14 of Iyar the Passover as the Torah requires for people that did not manage to make the first one.
