The SO3 moves to the cold end of your boiler and condenses on surfaces with temperatures below acid dew issue (ADP). This is particularly the situation from the rotary air heater, where SO3 condenses and kinds sulfuric acid deposits. Keep this medicine within the container it arrived in, tightly closed. https://travisakszh.blogsvila.com/18630922/top-guidelines-of-pentol-4d