Certainly, Imām Ibn Taymīyah had errors in both aqidah and fiqh.
Nevertheless, the Imām of the Hanafis of his time Badr ud-Din al-Ayni, who lived in the same century as Ibn Taymīyah, wrote:
"Shaykh al-Islam, the unique, the great Scholar, the defender AGAINST AHL UL-BIDA'..."