Oil boilers are typically preferred for larger buildings, although small models may be appropriate in some homes. Both hot water and steam systems are easier to adjust when using a gas-powered boiler.
Oil boilers are typically more expensive to install than gas boilers, and operating costs tend to be similar in areas where natural gas or propane is available. For small homes, simpler systems also offer better convenience.
Larger homes have proportionally less surface area compared to total volume, so less heat is lost to the environment through the walls. While larger homes require larger systems, the potential savings of oil boilers in certain areas may make them a more attractive option.