If a Hanafi makes جمع بين الصلاة, would we say the salaah that he read out of its time is invalid?
بِسْمِ اللهِ الرَّحْمنِ الرَّحِيْم
In the name of Allah, the Most Gracious, the Most Merciful
In the Hanafi school, the Zuhr/Asr prayers and Maghrib/Isha prayers may only be combined during Hajj. In the Shafi’i and Hanbali schools, it is allowed to combine these two prayers while travelling a long distance. So if you are asking whether a person who follows the Hanafi school may combine those prayers while travelling, the answer is that according to their own school it is not allowed to do so.
Imam Quduri explains, “Combining prayers for the traveller is allowed in practice but not in point of time.” By this, he means that you can perform one prayer at the end of the time and the other prayer at the beginning of the time, but all prayers must still be done in their own respective times.
Only Allah knows best
Written by Maulana Mustafa Umar
Checked and approved by Mufti Mohammed Tosir Miah
Darul Ifta Birmingham
 See Mukhtasar Al-Quduri p. 61, Taha Publishers, 2010