Gas heaters are usually paired with another heat source. Fireplace inserts and wall-mounted units that burn natural gas or propane are most common.
Gas flows through lines into the heater, where it’s lit by a pilot light or an electric starter. All gas heaters should also have a shutoff valve.
Most gas heaters vent to an outside wall. A blocked vent can send fumes back into your home. Ventless gas heaters can raise humidity in your home. Make sure humidity stays below 50%.