Always unplug the heater before cleaning. The outside of heaters can be cleaned with a damp cloth. Using a vacuum with a dust brush attachment can clean the front and rear grills. The internal parts of a heater can be cleaned by using a blow dryer or can of compressed air. If there are heavy deposits, you may need to use a long cotton swab or paintbrush, which would be long enough to reach inside of the heater. Caution should be taken when cleaning your heater to prevent any damage to the heater. IMPORTANT: We do not recommend opening heaters to clean them as it can void the warranty as well as cause a safety hazard if it is not disassembled or reassembled properly.