Ensure your stove is operating at the correct temperature by using this magnetic thermometer that attaches to your stove pipe. If your stove is too cold then creosote deposits will form, if its too hot then you are wasting energy and could damage your Ecofan.

Installation
Attaches magnetically, directly to metal flue pipe. Optimal location is at eye level, no less than 12" above the top of the stove, where you can easily see it in the room. The Chimguard model can also be used to attach directly onto your stove or inset fire 

Easy to Use
Consult your stove manufacturer's manual and recommendations. Approximate guidelines below, if placed at eyelevel on single wall flue pipe, for best operation:-

475° and higher: Wasting energy, possibly overheating. While this temperature will often be reached on initial firing, not advised for normal operation. Could ignite existing chimney deposits.

230°F to 475°F: Safe operating temperature. Complete combustion and best efficiency.

Less than 230°F: Temperature too low. Incomplete combustion, causing smoke, soot, and hazardous creosote. Open draught and/or add more fuel.

Stove Thermometer - Product description