Have dealer show you how to clean it first!
My Pacific Energy Vista is out of commission right now after cleaning the liner (exhaust flue). The baffle in the insert must be removed in order to do this and is designed so poorly it will not go back in even after hours of back and arm-wrenching work. If you want to do your own chimney sweeping (it's easy), make sure the insert will actually go back together. We've missed many nights of potential cheery fires because of this and I'm wondering who'll step up to the plate (dealer or manufacturer) and get it working again.