Published by admin at February 23, 2015 Maintenance is essential with fireplace fans. Unlike a furnace that has a filter to catch dust and dirt, the fan on your fireplace has no filter, draws in air and with it dust and debris. This can build up on your fan and cause the performance to decline and eventually will seize up and stop working. The dirtier they get the harder they have to work and therefore use more energy (hydro) to operate.