Yes, you can close off a fireplace both temporarily and permanently with extremely wide price ranges. Temporary solutions involve fireplace plugs that can be inflated to block air and deflated to open the fireplace, covers, and boards. Permanent methods of shutting off fireplaces usually involve bricking up the fireplace or covering it with drywall. No matter the method, it’s probably best to hire a professional.

In some cases, you can use a fireplace once the insert has been removed. However, before burning a fire, you must have a professional inspect it and the chimney to make sure they're functioning properly and no damage has occurred from removing the insert. That’s because using a fireplace without an insert could create fire hazards due to issues with airflow and heat dispersion, depending on the fireplace design and material. A professional can advise on whether you should make certain repairs or modifications before using your fireplace as an open hearth.

According to the National Fire Protection Association’s Code NFPA 25 (titled “Standard for the Inspection, Testing, and Maintenance of Water-Based Fire Protection Systems”), private fire hydrants must undergo inspection once per year, with an accompanying flow test and any necessary maintenance performed on the same schedule. Keep in mind that your town, city, or county may adopt more or less strict testing requirements. 

In most cases, having a fire hydrant installed on your property, whether it’s maintained by you personally or your municipality, will reduce your insurance premiums. Its proximity to any buildings on the property will reduce the time it takes to put out a fire, thus reducing the resulting damage.