I have wood siding too. But the woodpeckers do not bother it. Instead they like to bring their nuts to the sides of my windows. They stick the nuts in the small cracks on the sides of the windows and peck away.
When I open the windows in the spring, I have to wipe away the nuts they have pushed into the cracks.

Maybe they are helping to insulate around my windows :-) But I doubt it.

Steem on,
Mike