For overnight burning, load the heater at least half an hour before going to bed. Only turn the air supply down to minimum once all the wood is charred (about 15-20 minutes) to avoid creosote problems. Most heaters should still burn for eight hours without difficulty and you will have far less creosote problems than if you fill the heater and turn it to slow-burn straight away. However, long periods of slow burning will always produce more creosote than burning on medium or h