Yes. They should guarantee that they will perform their inspections in accordance both with a specific standard of professional practice and the terms and conditions of their written inspection agreement and scope of work. Because professional inspectors cannot predict the future, they should not be expected to provide any guarantees regarding the continued performance of or the efficiency of any system or component inspected or conditions which are not visible or which are not able to be determined in the course of the inspection.
Professional home inspectors are to houses what doctors who perform general physical examinations are to patients. They perform general examinations and recommend further examinations and evaluations by specialists when they believe that it is necessary to do so. Neither a doctor nor a professional home inspector can guarantee that they have “found everything” in the course of performing their respective work and they cannot and are not expected to predict the future. Both are highly trained and skilled professionals who do the best that is possible within the scope and limits which define their work. That is all anyone can or should expect or ask of either.