Quote Originally Posted by bretsk2500 View Post
the only thing I can think of is it's to add water into the heat exchanger to make steam and blow the creosote out of it...
Ya, that creosote can be deadly. The heat exchangers I've used can easily cause the chimney temp to drop to a point where the flue gas condenses on the chimney. The creosote will liquefy and plate out on the heat exchanger. The trick is to keep the stack discharge temperature high enough so the gas won't condense.
A creosote fire is something to behold, once it takes off, it's kinda like a jet engine. It's wise to have some fire snuffing sticks near the stove. They are kind of like a road flare. Apparently burn out the oxygen and starve the creosote fire.