A good question. It is unlikely that any heater repairs and servicing have been logged along with the Van servicing. When heaters are sent to reputable service centres such as Butler Technik, then there is a strong possibility that there weill be a silver foil label afixed to the heater with the date of last repair and job number etc. If there is no extra label attached, the the heater service record will remain unknown. Is your heater currently functioning okay?