Owners of vehicles that are equipped with these coolant heaters are advised not to operate the heaters until they have been repaired. Prevost will inspect the coolant heaters, replace the damaged components, and clean the heater’s internal components, as necessary. In addition, Prevost will adjust the air to fuel ratio. All repairs will be performed free of charge. Owner notification letters were mailed May 17, 2024. Owners may contact Prevost customer service at 1-866-870-2046. Prevost’s number for this recall is ER24-14.