Fireplace inserts have several potential disadvantages. The cost of the insert and its installation can be a significant investment, as the process can be complicated and expensive, particularly if modifications to the existing fireplace are necessary. Aesthetically, some people find that inserts lack the traditional look and authentic ambiance of an open, crackling fire. There are also ongoing costs for maintenance, cleaning, and fuel. Fuel type can be a limitation; for example, an insert may be unusable if you don't have access to its specific fuel source. Maintenance and repairs can also require specialized services, especially for gas or electric models. Finally, while an insert is more efficient than an open fireplace, it may not heat a home as evenly as a central HVAC system.

The cost to clean and inspect an oil-fired chimney generally ranges from $150 to $500. The price is influenced by factors such as the chimney's height, the level of soot buildup, local labor costs, and whether any additional repairs or liner replacements are required.

Creosote logs can help to reduce new creosote build-up by about 60%, however they don’t replace regular cleaning. While creosote logs can help to prevent build-up of creosote in your chimney, they won’t remove build-up that’s already there. Creosote logs can be used as a preventative measure in conjunction with regular cleaning, but you will still need to clean your chimney about once per year.

Some types of electric fireplaces use more electricity than others. Models that produce 1,500 watts will have more of an effect on your heating bill than 750-watt models. 

Electric fireplaces use an average of $1.85 of electricity every eight hours. These minimal operational costs aren’t likely to make a big difference in your electric bill—unless you’re using it as a primary heating source for your home and it’s running most of the time.