A friend of mine suffers from rheumatism. Therefore, when he prays at home, he uses hot water for Wudu' (ablution). And when he prays at work, he performs Tayammum (dry ablution with clean earth)
due to the unavailability of hot water there. Is the Salah (Prayer) he performs with Tayammum valid?
It is not permissible for your friend to offer Salah with Tayammum in the stated situation, because he is a resident and can easily get hot water by returning home or by any other means.May Allah grant us success. May peace and blessings be upon our Prophet Muhammad, his family, and Companions.