Ask Mr. Smarty Plants

We would certainly rather you burn it than plant it, as it is non-native. Here is a previous answer on that plant. Some non-natives, such as oleander, are so poisonous that you cannot even burn it, because of the poisonous vapors it will release in the air. We don't believe that is the case with photinia, but we also don't know much about burning in a fireplace, so we will see what we can find.

To begin with, burning the limbs of a shrub seems more like burning trash than using firewood. Don't just dump that day's cuttings in the fireplace and expect to be happy with the result. Wait until all the leaves are gone, they will just smoke, and don't use twigs and small branches, unless perhaps for tinder. It should be considered as a softwood, so remember that when you are reading our references.

This first reference is from the U.K, so you may not recognize the trees mentioned, but the points about seasoning and storage are good. That reference is from Wildeye: Firewood. From CBS News Is Your Fireplace Ready?

Finally, please don't plant any more photinia, even if you can use it for firewood.