With the exception of the 18" fireplace inserts which will run until turned off, each unit can be set to a specific temperature. The unit will then start or stop as needed to maintain that setting. Because of this, it can be difficult to figure the exact usage without specialized equipment--1400 watts would only applicable when the heater is running.
We can calculate the estimated cost of use of a fireplace insert with three pieces of information:
- The wattage. For most fireplace inserts this is 1400 watts, though some of the larger models run on 1500 watts.
- The estimated daily number of hours of used.
- The rate per kilowatt-hour charged by your local electric company. This can be obtained from your utility bill.
The formula for estimating cost of use is:
You have a 1400-watt fireplace insert that you run for three hours each evening. The local rate for usage in your area is 15.46¢ per kWh.
The cost of running your insert for three hours per day would be around 65 cents, but only if it ran nonstop. Depending on your temperature selection on the unit and that of your home, it could be less.