Disclosed is a volatile liquid emanation system consisting of a plug-in device and replaceable refills. The refills have a reservoir housing containing a liquid reservoir of volatile liquid and a wick extending from the inside to outside of the reservoir. The device has a housing with plug pins on the rear, a heater inside, an aperture that holds the releasable refill and a vent for the vapour. The refill receiving means holding the refill within the device housing such that the side of the refill adjacent the refill aperture is contiguous with the device housing wall. The refill aperture may be a slot in the side the device. The refill may be provided with a carrier member that connects to the reservoir housing and supports the wick.