Method of draining a system for anchoring a structural cable to a construction element, the anchor system comprising a first chamber delimited by an envelope, the first chamber containing a first part of the structural cable and a first filling material, the method comprising: inserting at least one heating element into the first filling material via an opening in the envelope of the first chamber; heating the first filling material with the aid of the heating element to fluidize some or all of the first filling material; and extracting the fluidized first filling material via an opening in the envelope of the first chamber.