It may take a bit of time before you get a response to your email, @Flatcat.
The hotel itself is not continually staffed. It is owned by the same man who owns the bar just down the street. (Which is the place where you get your room key and also is the only place to eat, btw.) As this is a slow time of year for both businesses, it would not be a surprise if he were taking a vacation.
In 2014, I wanted to phone them to make a booking a day or two in advance. There was never any answer. When I got there, I discovered that it was fully booked by a group from Ireland. I was advised by two Spanish ladies to walk down to Atapuerca, an easy walk, and stayed in the newish private Albergue, El Peregrino, which also has private rooms- a really nice place.
Peaceable Projects Inc. is a U.S.-based non-profit group that brings the vast resources of the wide world together with the ongoing needs of the people who live, work, and travel on the Camino de Santiago pilgrim trail network in Spain.